chore(knowledge): move canonical docs to shared SoMC wiki

.gitignore

@@ -1,5 +1,6 @@
 .gradle/
 build/
+.local-server/
 out/
 .idea/
 *.iml

AGENTS.md

@@ -1,40 +1,9 @@
-# Spigot Quest Board Agent Guide
+# spigot-quest-board agent entrypoint
 
-## Project
+The canonical stories, engineering guidance, and **all process documents** are in the private [SoMC OKF wiki](https://git.garvis.dev/dmg/somc-okf/src/branch/main/index.md).
 
-Spigot Quest Board is a Java 25 plugin for Purpur 26.2. It provides shared physical quest boards where players escrow rewards, deliver requested block items, and claim delivered or returned items.
+Before work, read the sibling `../somc-okf/index.md`, `../somc-okf/processes/index.md`, `../somc-okf/projects/spigot-quest-board/index.md`, `engineering.md` in that project section, and relevant `../somc-okf/user-stories/spigot-quest-board/` stories. Also follow the parent workspace `AGENTS.md` when present.
 
-## Canonical knowledge
+For standalone checkouts, start at the [project page](https://git.garvis.dev/dmg/somc-okf/src/branch/main/projects/spigot-quest-board/index.md) and [shared process](https://git.garvis.dev/dmg/somc-okf/src/branch/main/processes/development.md). Obtain wiki access before feature work; do not recreate a local knowledge bundle. Source builds do not require private wiki access.
 
-- `knowledge/` is the canonical OKF v0.1 knowledge bundle.
-- Read `knowledge/index.md` and the relevant documents in `knowledge/user-stories/` before changing behavior.
-- Every feature or behavior change requires an approved user story with task-list acceptance criteria.
-- Preserve unknown YAML frontmatter fields when editing knowledge documents.
-- Keep `knowledge/index.md`, `knowledge/log.md`, and `knowledge/user-stories/index.md` current.
-
-## Development
-
-- Compile against the Purpur API version declared in `build.gradle.kts`.
-- Use Java 25 and enable strict compiler linting.
-- Prefer small, server-independent domain objects and services that can be unit tested.
-- Use test-driven development where practical: add a failing test, implement the minimum behavior, then refactor.
-- Treat escrow, completion, cancellation, expiry, and claiming as atomic state transitions. Never duplicate or silently discard player items.
-- Key players by UUID, not display name.
-- Persist board, quest, escrow, and claim state safely across restarts using atomic file replacement where supported.
-- Use UTC and RFC 3339 timestamps for persisted or documented date-times.
-- Keep player-facing command autocomplete permission-aware and context-sensitive.
-- Use Purpur's supported Paper dialog API for native dialog interfaces.
-
-## Verification
-
-Run before completing a story:
-
-```bash
-./gradlew clean check jar
-```
-
-Mark acceptance criteria complete only after implementation and verification.
-
-## Git
-
-Use conventional commits in the form `type(scope): description`, with summaries under 72 characters.
+Development follows [Development cycle](https://git.garvis.dev/dmg/somc-okf/src/branch/main/runbooks/development-cycle.md): approved stories, failing tests, passing implementation, verification, then source/wiki commit and push. GitOps updates are committed locally **without pushing**; only [Do release](https://git.garvis.dev/dmg/somc-okf/src/branch/main/runbooks/do-release.md) authorizes a reviewed GitOps push.

README.md

@@ -1,12 +1,12 @@
 # Spigot Quest Board
 
-A Purpur 26.2 plugin for shared physical quest boards. Players can escrow rewards for requested block items, deliver those blocks at any quest board, and claim delivered or returned items safely.
+A Purpur 26.2 plugin for shared physical quest boards. Players can escrow rewards for requested items, deliver those items at any quest board, and claim delivered or returned items safely.
 
-The approved behavior is specified in the [OKF knowledge bundle](knowledge/index.md).
+The approved behavior is specified in the [SoMC OKF wiki](https://git.garvis.dev/dmg/somc-okf/src/branch/main/projects/spigot-quest-board/index.md).
 
 ## Status
 
-Administrators can register persistent shared quest boards by targeting a block within five blocks and running `/questadmin createboard`. Right-clicking any registered board opens a native dialog where a player can request a block and quantity while escrowing the exact reward stack held in their main hand. Every board and `/quests list` show the same active quests with requested blocks, rewards, issuers, and time remaining. Delivery and claims remain under development.
+Administrators can register persistent shared quest boards by targeting a block within five blocks and running `/questadmin createboard`. They can instead run `/questadmin createboard physical` to generate a five-wide oak board above the targeted ground anchor, with glowing centered title and browsing-instruction signs above three decorative signs; its visible panel blocks and all five signs are registered. Right-clicking any registered board opens a compact native dashboard with dedicated browsing, creation, and claim screens. A player can request any inventory item material and quantity while escrowing the exact reward stack held in their main hand. Every board and `/quests list` show the same active quests with requested items, rewards, issuers, and time remaining; custom reward names are shown together with their material type. Players can complete quests at any board or with `/quests complete <quest>` by delivering the required items. Exact escrowed rewards are granted immediately, and delivered items are held for the issuer. Issuers can cancel their own active quests at any board or with `/quests cancel <quest>`. Completed deliveries and rewards from cancelled or seven-day-expired quests are held durably and can be collected at any board or with `/quests claim`; inventory overflow drops at the claimant's feet.
 
 ## Requirements
 
@@ -21,9 +21,9 @@ Administrators can register persistent shared quest boards by targeting a block
 
 The plugin JAR is written to `build/libs/`.
 
-## Planned player commands
+## Player commands
 
-Player commands are disabled by default and can be enabled by an administrator.
+Player commands are disabled by default and can be enabled persistently by an administrator. When disabled, players within five blocks of a registered board can still use `/quests create <item> <quantity>` with material and quantity autocomplete; other player command forms remain disabled.
 
 ```text
 /quests
@@ -34,12 +34,13 @@ Player commands are disabled by default and can be enabled by an administrator.
 /quests claim
 ```
 
-## Planned administration
+## Administration
 
 The `spigotquestboard.admin` permission is granted to server operators by default.
 
 ```text
 /questadmin createboard
+/questadmin createboard physical
 /questadmin commands <enable|disable>
 ```
 

knowledge/index.md

@@ -1,15 +0,0 @@
----
-type: Index
-title: Spigot Quest Board Knowledge
-description: Entry point for the Spigot Quest Board OKF knowledge bundle.
-okf_version: "0.1"
----
-
-# Spigot Quest Board Knowledge
-
-This bundle specifies shared physical quest boards, reward escrow, block deliveries, item claims, player commands, administration, persistence, and plugin delivery requirements.
-
-## Explore
-
-- [User stories](user-stories/index.md)
-- [Knowledge log](log.md)

knowledge/log.md

@@ -1,49 +0,0 @@
----
-type: Log
-title: Spigot Quest Board Knowledge Log
-description: Chronological record of material decisions affecting Spigot Quest Board.
----
-
-# Spigot Quest Board Knowledge Log
-
-## 2026-09-05 — Initial quest-board design
-
-- Administrators create physical quest boards, and every board exposes the same global quests and claims.
-- Players create quests by selecting a requested block material and quantity and escrowing reward items from their inventory.
-- Completing players deliver the requested block items at a board and immediately receive the escrowed reward.
-- Delivered blocks remain held by the quest system until the issuer claims them at a board.
-- Cancelled and seven-day-expired quests return escrowed rewards through the same claim system rather than direct inventory delivery.
-- Inventory overflow from rewards or claims is dropped at the receiving player's feet.
-- Player `/quests` commands are disabled by default so administrators can require physical-board interaction.
-- The board interface follows Spigot Base by using Purpur's supported native dialog API.
-
-## 2026-09-05 — Foundation started
-
-- Approved work begins with an OKF knowledge bundle, Java 25/Purpur 26.2 Gradle foundation, automated verification, and a public Gitea repository.
-
-## 2026-09-05 — Foundation completed
-
-- Published the project to the public `dmg/spigot-quest-board` Gitea repository.
-- Added strict Java 25/Purpur 26.2 Gradle builds, plugin metadata, a metadata regression test, and CI/release workflows modeled on Spigot Base.
-- Verified the plugin foundation and JAR with `./gradlew clean check jar`.
-
-## 2026-09-05 — Shared physical quest boards
-
-- Added durable world-UUID and block-coordinate board registration through `/questadmin createboard`.
-- Registered main-hand interactions open one shared native Purpur dialog while unregistered blocks remain untouched.
-- Persistence publishes a board only after an atomic YAML save succeeds and rejects duplicate locations.
-- Verified 11 tests and the plugin JAR with `./gradlew clean check jar`.
-
-## 2026-09-05 — Quest creation and reward escrow
-
-- Added board-dialog and `/quests create <block> <quantity>` creation using a valid block material, positive quantity, and the exact held reward stack.
-- Escrow preserves full Bukkit item metadata in durable Base64-backed YAML and rolls inventory removal back if persistence fails.
-- Quests receive UUID identifiers and UTC creation and seven-day expiration timestamps.
-- Verified 26 tests and the plugin JAR with `./gradlew clean check jar`.
-
-## 2026-09-05 — Shared quest browsing
-
-- Added globally shared active-quest listings to every board and to `/quests` and `/quests list`.
-- Listings include requested blocks, exact reward summaries, issuer names, and boundary-safe remaining durations.
-- Added persisted lifecycle status with backward-compatible active defaults and filtered stale quest IDs from contextual completion and cancellation suggestions.
-- Verified 37 tests and the plugin JAR with `./gradlew clean check jar`.

knowledge/user-stories/index.md

@@ -1,16 +0,0 @@
----
-type: Index
-title: Spigot Quest Board User Stories
-description: Catalog of user stories for the Spigot Quest Board plugin.
----
-
-# Spigot Quest Board User Stories
-
-1. [US-001: Build and release the plugin](us-001-build-and-release-plugin.md)
-2. [US-002: Create and use shared quest boards](us-002-create-and-use-shared-quest-boards.md)
-3. [US-003: Create a block-delivery quest](us-003-create-a-block-delivery-quest.md)
-4. [US-004: Browse available quests](us-004-browse-available-quests.md)
-5. [US-005: Deliver blocks and complete a quest](us-005-deliver-blocks-and-complete-a-quest.md)
-6. [US-006: Cancel an owned quest](us-006-cancel-an-owned-quest.md)
-7. [US-007: Expire quests and claim held items](us-007-expire-quests-and-claim-held-items.md)
-8. [US-008: Control player quest commands](us-008-control-player-quest-commands.md)

knowledge/user-stories/us-001-build-and-release-plugin.md

@@ -1,28 +0,0 @@
----
-type: User Story
-title: "US-001: Build and release the plugin"
-description: Give maintainers repeatable Purpur builds, automated verification, and versioned public Gitea releases.
-status: done
----
-
-# US-001: Build and release the plugin
-
-As a **plugin maintainer**, I want automated builds and releases modeled on Spigot Base so that tested, correctly versioned artifacts can be distributed consistently.
-
-## Acceptance criteria
-
-- [x] The Gradle project compiles against Purpur API `26.2.build.2618-stable` using a Java 25 toolchain.
-- [x] Compiler lint warnings fail the build.
-- [x] Automated JUnit 5 tests run as part of the Gradle check lifecycle.
-- [x] Plugin metadata declares the entrypoint, player and admin commands, and permissions.
-- [x] Pushes and pull requests build and test the plugin in Gitea Actions.
-- [x] Pull requests validate conventional commit messages.
-- [x] CI stores a development JAR as a workflow artifact.
-- [x] Main-branch conventional commits drive semantic versioning.
-- [x] A successful release builds a versioned JAR and attaches it to the corresponding Gitea release.
-- [x] The project is published in the public `dmg/spigot-quest-board` Gitea repository.
-- [x] Build files, Gradle wrapper, workflows, and release behavior follow `../spigot-base/` where applicable while using Spigot Quest Board names and identifiers.
-
-## Related
-
-- [User-story catalog](index.md)

knowledge/user-stories/us-002-create-and-use-shared-quest-boards.md

@@ -1,27 +0,0 @@
----
-type: User Story
-title: "US-002: Create and use shared quest boards"
-description: Let administrators establish persistent physical boards that expose one shared quest system.
-status: done
----
-
-# US-002: Create and use shared quest boards
-
-As an **administrator**, I want to turn a targeted block into a quest board so that players can interact with quests at controlled physical locations.
-
-## Acceptance criteria
-
-- [x] An authorized administrator can use `/questadmin createboard` to register the block they are targeting.
-- [x] Creation rejects a missing, invalid, or already registered target without changing state.
-- [x] Registered boards persist across server restarts with their world and block coordinates.
-- [x] Interacting with any registered board opens the quest-board interface.
-- [x] Every registered board exposes the same global quests and claimable items.
-- [x] The interface uses Purpur's supported native dialog API and follows the interaction style of Spigot Base.
-- [x] Ordinary block interaction is not intercepted at unregistered locations.
-- [x] Administrative actions require the `spigotquestboard.admin` permission, granted to server operators by default.
-- [x] Automated tests verify board registration, persistence, shared visibility, authorization, and interaction routing.
-
-## Related
-
-- [US-003: Create a block-delivery quest](us-003-create-a-block-delivery-quest.md)
-- [US-004: Browse available quests](us-004-browse-available-quests.md)

knowledge/user-stories/us-003-create-a-block-delivery-quest.md

@@ -1,28 +0,0 @@
----
-type: User Story
-title: "US-003: Create a block-delivery quest"
-description: Let a player request block items while safely escrowing an inventory-funded reward.
-status: done
----
-
-# US-003: Create a block-delivery quest
-
-As a **player**, I want to request a block material and quantity in exchange for items I already own so that another player can fulfill my request safely.
-
-## Acceptance criteria
-
-- [x] A player can create a quest through a registered quest board by selecting a valid block material, a positive quantity, and reward items from their inventory.
-- [x] Reward items must exist in the issuer's inventory and are removed only when quest creation succeeds.
-- [x] Removed rewards are held durably in escrow by the quest system.
-- [x] A created quest records a unique identifier, issuer UUID and current name, requested material and quantity, exact reward items, creation time, and expiration time.
-- [x] Each quest expires exactly seven days after successful creation.
-- [x] Invalid input, insufficient reward items, or persistence failure leaves the issuer's inventory unchanged and creates no quest.
-- [x] When player commands are enabled, `/quests create ...` provides equivalent validated creation behavior with contextual autocomplete.
-- [x] Quest state and item metadata survive server restarts without duplication or loss.
-- [x] Automated tests verify validation, escrow, rollback, timestamps, command routing, and persistence.
-
-## Related
-
-- [US-002: Create and use shared quest boards](us-002-create-and-use-shared-quest-boards.md)
-- [US-005: Deliver blocks and complete a quest](us-005-deliver-blocks-and-complete-a-quest.md)
-- [US-007: Expire quests and claim held items](us-007-expire-quests-and-claim-held-items.md)

knowledge/user-stories/us-004-browse-available-quests.md

@@ -1,25 +0,0 @@
----
-type: User Story
-title: "US-004: Browse available quests"
-description: Let players inspect globally available quests and their essential terms.
-status: done
----
-
-# US-004: Browse available quests
-
-As a **player**, I want to browse current quests so that I can decide which block deliveries to fulfill.
-
-## Acceptance criteria
-
-- [x] Every registered board lists the same active quests.
-- [x] Each listing shows the requested block material, quantity, reward, issuer, and time remaining.
-- [x] Remaining durations are clear and never display an expired quest as active.
-- [x] Completed, cancelled, and expired quests are excluded from the active listing.
-- [x] When player commands are enabled, `/quests` and `/quests list` provide the same active quest information in chat.
-- [x] Listing and autocomplete do not expose stale quest identifiers as completable or cancellable.
-- [x] Automated tests verify filtering, displayed fields, duration boundaries, and command aliases.
-
-## Related
-
-- [US-002: Create and use shared quest boards](us-002-create-and-use-shared-quest-boards.md)
-- [US-005: Deliver blocks and complete a quest](us-005-deliver-blocks-and-complete-a-quest.md)

knowledge/user-stories/us-005-deliver-blocks-and-complete-a-quest.md

@@ -1,29 +0,0 @@
----
-type: User Story
-title: "US-005: Deliver blocks and complete a quest"
-description: Let a player deliver requested blocks at a quest board and receive the escrowed reward.
-status: backlog
----
-
-# US-005: Deliver blocks and complete a quest
-
-As a **player**, I want to deliver requested blocks to a quest board so that I receive the promised reward and the issuer can claim my delivery.
-
-## Acceptance criteria
-
-- [ ] An active quest offers a Complete Quest action through every registered board.
-- [ ] Completion requires the delivering player to possess the full requested quantity of the exact block material.
-- [ ] Successful completion removes the requested blocks from the delivering player's inventory and stores them as a claim for the issuer.
-- [ ] Successful completion gives the exact escrowed reward items to the delivering player.
-- [ ] Reward items that do not fit are dropped safely at the delivering player's feet with a clear message.
-- [ ] The issuer is notified immediately when online or on their next login when offline that delivered blocks can be claimed at a quest board.
-- [ ] When player commands are enabled, `/quests complete <quest>` provides equivalent behavior with contextual autocomplete.
-- [ ] Completion is atomic and exactly one player can complete a quest, including simultaneous attempts.
-- [ ] Validation or persistence failure does not consume delivered blocks, release rewards, or change quest state.
-- [ ] Completed quests are no longer shown as active or completable.
-- [ ] Automated tests verify inventory validation, settlement, overflow, notifications, rollback, and concurrent completion protection.
-
-## Related
-
-- [US-003: Create a block-delivery quest](us-003-create-a-block-delivery-quest.md)
-- [US-007: Expire quests and claim held items](us-007-expire-quests-and-claim-held-items.md)

knowledge/user-stories/us-006-cancel-an-owned-quest.md

@@ -1,27 +0,0 @@
----
-type: User Story
-title: "US-006: Cancel an owned quest"
-description: Let an issuer cancel an active quest and reclaim its escrowed reward safely.
-status: backlog
----
-
-# US-006: Cancel an owned quest
-
-As a **quest issuer**, I want to cancel my active quest so that I can reclaim the reward when I no longer need the requested blocks.
-
-## Acceptance criteria
-
-- [ ] An issuer can cancel their own active quest through any registered board.
-- [ ] A player cannot cancel a quest issued by another player.
-- [ ] Completed, cancelled, and expired quests cannot be cancelled.
-- [ ] Cancellation removes the quest from active listings and converts its exact escrowed reward into a claim for the issuer.
-- [ ] The reward is not inserted directly into the issuer's inventory during cancellation.
-- [ ] When player commands are enabled, `/quests cancel <quest>` provides equivalent behavior and only autocompletes the player's cancellable quest identifiers.
-- [ ] Cancellation and simultaneous completion are serialized so items cannot be duplicated or lost.
-- [ ] Persistence failure leaves the quest active and its reward escrowed.
-- [ ] Automated tests verify ownership, state validation, claim creation, autocomplete, rollback, and completion races.
-
-## Related
-
-- [US-003: Create a block-delivery quest](us-003-create-a-block-delivery-quest.md)
-- [US-007: Expire quests and claim held items](us-007-expire-quests-and-claim-held-items.md)

knowledge/user-stories/us-007-expire-quests-and-claim-held-items.md

@@ -1,30 +0,0 @@
----
-type: User Story
-title: "US-007: Expire quests and claim held items"
-description: Hold delivered blocks and returned rewards until their owner safely claims them.
-status: backlog
----
-
-# US-007: Expire quests and claim held items
-
-As a **quest issuer**, I want delivered blocks and returned rewards held at the shared quest board so that I can retrieve them safely.
-
-## Acceptance criteria
-
-- [ ] An uncompleted quest expires seven days after its creation time.
-- [ ] Expiration removes the quest from active listings and converts its exact escrowed reward into a claim for the issuer.
-- [ ] Completed-quest claims contain the exact block items delivered by the completing player.
-- [ ] Claims from completion, cancellation, and expiration can be collected through any registered board.
-- [ ] The board clearly distinguishes delivered blocks from returned rewards.
-- [ ] Online issuers receive a real-time message when items become claimable.
-- [ ] Offline issuers receive a message on their next login.
-- [ ] When player commands are enabled, `/quests claim` collects the same pending claims.
-- [ ] Items are inserted into the claimant's inventory where space permits; overflow is dropped safely at their feet with a clear message.
-- [ ] A claim is removed only after all of its items have been inserted or dropped successfully.
-- [ ] Pending claims and notification state survive logout and server restart without duplication or loss.
-- [ ] Automated tests verify expiry boundaries, each claim source, notifications, overflow, failure recovery, and persistence.
-
-## Related
-
-- [US-005: Deliver blocks and complete a quest](us-005-deliver-blocks-and-complete-a-quest.md)
-- [US-006: Cancel an owned quest](us-006-cancel-an-owned-quest.md)

knowledge/user-stories/us-008-control-player-quest-commands.md

@@ -1,27 +0,0 @@
----
-type: User Story
-title: "US-008: Control player quest commands"
-description: Let administrators require physical-board interaction by controlling access to player quest commands.
-status: backlog
----
-
-# US-008: Control player quest commands
-
-As an **administrator**, I want to enable or disable player quest commands so that I can require players to use physical quest boards.
-
-## Acceptance criteria
-
-- [ ] Player `/quests` commands are disabled by default.
-- [ ] An authorized administrator can use `/questadmin commands enable|disable` with contextual autocomplete.
-- [ ] The command setting persists across server restarts.
-- [ ] When disabled, `/quests`, `list`, `create`, `complete`, `cancel`, and `claim` reject execution with a clear message directing the player to a quest board.
-- [ ] Disabling commands does not prevent any equivalent action through a registered board.
-- [ ] `/questadmin` remains available to authorized administrators regardless of the player-command setting.
-- [ ] Unauthorized users cannot change the setting.
-- [ ] Automated tests verify the default, persistence, authorization, every gated subcommand, and autocomplete.
-
-## Related
-
-- [US-002: Create and use shared quest boards](us-002-create-and-use-shared-quest-boards.md)
-- [US-003: Create a block-delivery quest](us-003-create-a-block-delivery-quest.md)
-- [US-007: Expire quests and claim held items](us-007-expire-quests-and-claim-held-items.md)

src/main/java/games/dmg/spigotquestboard/BoardFacing.java

@@ -0,0 +1,54 @@
+package games.dmg.spigotquestboard;
+
+import org.bukkit.block.BlockFace;
+
+/** The direction from the board toward its viewer. */
+enum BoardFacing {
+    NORTH(0, -1),
+    EAST(1, 0),
+    SOUTH(0, 1),
+    WEST(-1, 0);
+
+    private final int x;
+    private final int z;
+
+    BoardFacing(int x, int z) {
+        this.x = x;
+        this.z = z;
+    }
+
+    int x() {
+        return x;
+    }
+
+    int z() {
+        return z;
+    }
+
+    int rightX() {
+        return -z;
+    }
+
+    int rightZ() {
+        return x;
+    }
+
+    BlockFace blockFace() {
+        return switch (this) {
+            case NORTH -> BlockFace.NORTH;
+            case EAST -> BlockFace.EAST;
+            case SOUTH -> BlockFace.SOUTH;
+            case WEST -> BlockFace.WEST;
+        };
+    }
+
+    static BoardFacing towardPlayer(BlockFace playerFacing) {
+        return switch (playerFacing) {
+            case NORTH -> SOUTH;
+            case EAST -> WEST;
+            case SOUTH -> NORTH;
+            case WEST -> EAST;
+            default -> throw new IllegalArgumentException("Player must face a cardinal direction");
+        };
+    }
+}

src/main/java/games/dmg/spigotquestboard/BoardProximity.java

@@ -0,0 +1,8 @@
+package games.dmg.spigotquestboard;
+
+import java.util.UUID;
+
+@FunctionalInterface
+interface BoardProximity {
+    boolean isWithin(UUID worldId, double x, double y, double z, double maximumDistance);
+}

src/main/java/games/dmg/spigotquestboard/BoardRegistry.java

@@ -1,12 +1,13 @@
 package games.dmg.spigotquestboard;
 
 import java.io.IOException;
+import java.util.Collection;
 import java.util.LinkedHashMap;
 import java.util.Map;
 import java.util.Objects;
 import java.util.Set;
 
-final class BoardRegistry {
+final class BoardRegistry implements BoardProximity {
     private final BoardRepository repository;
     private Map<BoardId, RegisteredBoard> boards;
 
@@ -16,12 +17,22 @@ final class BoardRegistry {
     }
 
     synchronized BoardRegistrationResult register(RegisteredBoard board) throws IOException {
-        Objects.requireNonNull(board, "board");
-        if (boards.containsKey(board.id())) {
-            return BoardRegistrationResult.ALREADY_REGISTERED;
-        }
+        return registerAll(Set.of(Objects.requireNonNull(board, "board")));
+    }
+
+    synchronized BoardRegistrationResult registerAll(Collection<RegisteredBoard> additions)
+        throws IOException {
+        Objects.requireNonNull(additions, "additions");
         Map<BoardId, RegisteredBoard> candidate = new LinkedHashMap<>(boards);
-        candidate.put(board.id(), board);
+        for (RegisteredBoard board : additions) {
+            Objects.requireNonNull(board, "board");
+            if (candidate.putIfAbsent(board.id(), board) != null) {
+                return BoardRegistrationResult.ALREADY_REGISTERED;
+            }
+        }
+        if (additions.isEmpty()) {
+            return BoardRegistrationResult.CREATED;
+        }
         repository.save(new BoardState(Set.copyOf(candidate.values())));
         boards = Map.copyOf(candidate);
         return BoardRegistrationResult.CREATED;
@@ -35,6 +46,34 @@ final class BoardRegistry {
         return boards.size();
     }
 
+    @Override
+    public synchronized boolean isWithin(
+        java.util.UUID worldId,
+        double x,
+        double y,
+        double z,
+        double maximumDistance
+    ) {
+        Objects.requireNonNull(worldId, "worldId");
+        if (maximumDistance < 0.0) {
+            return false;
+        }
+        double maximumDistanceSquared = maximumDistance * maximumDistance;
+        return boards.keySet().stream()
+            .filter(id -> id.worldId().equals(worldId))
+            .anyMatch(id -> {
+                double deltaX = x - id.x();
+                double deltaY = y - id.y();
+                double deltaZ = z - id.z();
+                return deltaX * deltaX + deltaY * deltaY + deltaZ * deltaZ
+                    <= maximumDistanceSquared;
+            });
+    }
+
+    synchronized Map<BoardId, RegisteredBoard> registeredBoards() {
+        return Map.copyOf(boards);
+    }
+
     private static Map<BoardId, RegisteredBoard> index(BoardState state) throws IOException {
         Map<BoardId, RegisteredBoard> indexed = new LinkedHashMap<>();
         for (RegisteredBoard board : state.boards()) {

src/main/java/games/dmg/spigotquestboard/BukkitIssuerNotifier.java

@@ -0,0 +1,74 @@
+package games.dmg.spigotquestboard;
+
+import java.io.IOException;
+import java.time.Clock;
+import java.util.Objects;
+import java.util.UUID;
+import java.util.logging.Level;
+import java.util.logging.Logger;
+import org.bukkit.Server;
+import org.bukkit.entity.Player;
+import org.bukkit.event.EventHandler;
+import org.bukkit.event.Listener;
+import org.bukkit.event.player.PlayerJoinEvent;
+
+final class BukkitIssuerNotifier implements IssuerNotifier, Listener {
+    private final QuestService quests;
+    private final Server server;
+    private final Logger logger;
+    private final Clock clock;
+
+    BukkitIssuerNotifier(QuestService quests, Server server, Logger logger) {
+        this(quests, server, logger, Clock.systemUTC());
+    }
+
+    BukkitIssuerNotifier(QuestService quests, Server server, Logger logger, Clock clock) {
+        this.quests = Objects.requireNonNull(quests, "quests");
+        this.server = Objects.requireNonNull(server, "server");
+        this.logger = Objects.requireNonNull(logger, "logger");
+        this.clock = Objects.requireNonNull(clock, "clock");
+    }
+
+    @Override
+    public void notifyIfOnline(UUID issuerId) {
+        Player player = server.getPlayer(issuerId);
+        if (player != null && player.isOnline()) {
+            deliver(player);
+        }
+    }
+
+    @EventHandler
+    public void onPlayerJoin(PlayerJoinEvent event) {
+        Player player = event.getPlayer();
+        int count = quests.activeQuests(clock.instant()).size();
+        String summary = switch (count) {
+            case 0 -> "No quests are currently available.";
+            case 1 -> "1 quest is currently available.";
+            default -> count + " quests are currently available.";
+        };
+        player.sendMessage(summary + " Visit the quest board to accept or create a quest.");
+        if (!quests.claimsFor(player.getUniqueId()).isEmpty()) {
+            player.sendMessage(
+                "You have items waiting to be claimed. Visit the quest board to collect them."
+            );
+        }
+        deliver(player);
+    }
+
+    void deliver(Player player) {
+        for (IssuerNotification notification
+            : quests.pendingNotifications(player.getUniqueId())) {
+            player.sendMessage(notification.message());
+            try {
+                quests.markNotificationDelivered(notification.id());
+            } catch (IOException exception) {
+                logger.log(
+                    Level.WARNING,
+                    "Could not persist delivery of issuer notification " + notification.id()
+                        + "; it will be retried",
+                    exception
+                );
+            }
+        }
+    }
+}

src/main/java/games/dmg/spigotquestboard/BukkitItemMaterialCatalog.java

@@ -6,11 +6,11 @@ import java.util.Locale;
 import java.util.Optional;
 import org.bukkit.Material;
 
-final class BukkitBlockMaterialCatalog implements BlockMaterialCatalog {
+final class BukkitItemMaterialCatalog implements ItemMaterialCatalog {
     @Override
-    public Optional<String> normalizeBlock(String input) {
+    public Optional<String> normalizeItem(String input) {
         Material material = Material.matchMaterial(input == null ? "" : input);
-        if (material == null || material.isAir() || !material.isBlock()) {
+        if (material == null || material.isAir() || !material.isItem()) {
             return Optional.empty();
         }
         return Optional.of(material.name());
@@ -20,7 +20,7 @@ final class BukkitBlockMaterialCatalog implements BlockMaterialCatalog {
     public List<String> suggest(String prefix) {
         String normalizedPrefix = prefix.toUpperCase(Locale.ROOT);
         return Arrays.stream(Material.values())
-            .filter(material -> material.isBlock() && !material.isAir())
+            .filter(material -> material.isItem() && !material.isAir())
             .map(Material::name)
             .filter(name -> name.startsWith(normalizedPrefix))
             .sorted()

src/main/java/games/dmg/spigotquestboard/BukkitPhysicalBoardWorld.java

@@ -0,0 +1,137 @@
+package games.dmg.spigotquestboard;
+
+import java.util.List;
+import java.util.Objects;
+import net.kyori.adventure.text.Component;
+import net.kyori.adventure.text.format.NamedTextColor;
+import net.kyori.adventure.text.format.TextDecoration;
+import org.bukkit.Material;
+import org.bukkit.World;
+import org.bukkit.block.Block;
+import org.bukkit.block.BlockState;
+import org.bukkit.block.Sign;
+import org.bukkit.block.data.BlockData;
+import org.bukkit.block.data.type.WallSign;
+import org.bukkit.block.sign.Side;
+import org.bukkit.block.sign.SignSide;
+
+final class BukkitPhysicalBoardWorld implements PhysicalBoardWorld {
+    private static final Component DECORATIVE_TEXT = Component.text("xxxxxxxx")
+        .color(NamedTextColor.DARK_GREEN)
+        .decorate(TextDecoration.OBFUSCATED);
+    private static final List<Component> TITLE_TEXT = List.of(
+        Component.text("Quest"), Component.text("Board"), Component.empty(), Component.empty()
+    );
+    private static final List<Component> INSTRUCTION_TEXT = List.of(
+        Component.text("Right-click"), Component.text("a sign below"),
+        Component.text("to browse"), Component.text("quests")
+    );
+    private final World world;
+
+    BukkitPhysicalBoardWorld(World world) {
+        this.world = Objects.requireNonNull(world, "world");
+    }
+
+    @Override
+    public boolean isEmpty(BoardId location) {
+        return block(location).getType().isAir();
+    }
+
+    @Override
+    public Object snapshot(BoardId location) {
+        return block(location).getState();
+    }
+
+    @Override
+    public void place(PhysicalBoardPlan.Placement placement, BoardFacing facing) {
+        Block block = block(placement.location());
+        Material material = Objects.requireNonNull(
+            Material.matchMaterial(placement.material()),
+            "Unknown physical board material " + placement.material()
+        );
+        block.setType(material, false);
+        if (!placement.sign()) {
+            return;
+        }
+
+        BlockData data = block.getBlockData();
+        if (!(data instanceof WallSign wallSign)) {
+            throw new IllegalStateException("Oak wall sign did not create wall-sign data");
+        }
+        wallSign.setFacing(facing.blockFace());
+        block.setBlockData(wallSign, false);
+        BlockState state = block.getState();
+        if (!(state instanceof Sign sign)) {
+            throw new IllegalStateException("Oak wall sign did not create sign state");
+        }
+        List<Component> lines = signLines(placement.signKind());
+        SignSide front = sign.getSide(Side.FRONT);
+        for (int line = 0; line < lines.size(); line++) {
+            front.line(line, lines.get(line));
+        }
+        front.setGlowingText(placement.signKind() != PhysicalBoardSignKind.DECORATIVE);
+        if (!sign.update(true, false)) {
+            throw new IllegalStateException("Could not configure physical quest-board sign");
+        }
+    }
+
+    @Override
+    public boolean matches(PhysicalBoardPlan.Placement placement, BoardFacing facing) {
+        return matches(placement, facing,
+            placement.signKind() != PhysicalBoardSignKind.DECORATIVE);
+    }
+
+    @Override
+    public boolean matches(
+        PhysicalBoardPlan.Placement placement, BoardFacing facing, boolean glowingText
+    ) {
+        Block block = block(placement.location());
+        Material material = Material.matchMaterial(placement.material());
+        if (material == null || block.getType() != material) {
+            return false;
+        }
+        if (!placement.sign()) {
+            return true;
+        }
+        if (!(block.getBlockData() instanceof WallSign wallSign)
+            || wallSign.getFacing() != facing.blockFace()
+            || !(block.getState() instanceof Sign sign)) {
+            return false;
+        }
+        SignSide front = sign.getSide(Side.FRONT);
+        if (front.isGlowingText() != glowingText) {
+            return false;
+        }
+        List<Component> expected = signLines(placement.signKind());
+        for (int line = 0; line < expected.size(); line++) {
+            if (!expected.get(line).equals(front.line(line))) {
+                return false;
+            }
+        }
+        return true;
+    }
+
+    @Override
+    public void restore(BoardId location, Object snapshot) {
+        if (!(snapshot instanceof BlockState state) || !state.update(true, false)) {
+            throw new IllegalStateException("Could not restore block at " + location);
+        }
+    }
+
+    static List<Component> signLines(PhysicalBoardSignKind kind) {
+        return switch (Objects.requireNonNull(kind, "kind")) {
+            case TITLE -> TITLE_TEXT;
+            case INSTRUCTION -> INSTRUCTION_TEXT;
+            case DECORATIVE -> List.of(
+                DECORATIVE_TEXT, DECORATIVE_TEXT, DECORATIVE_TEXT, DECORATIVE_TEXT
+            );
+        };
+    }
+
+    private Block block(BoardId location) {
+        if (!world.getUID().equals(location.worldId())) {
+            throw new IllegalArgumentException("Physical board location belongs to another world");
+        }
+        return world.getBlockAt(location.x(), location.y(), location.z());
+    }
+}

src/main/java/games/dmg/spigotquestboard/BukkitQuestClaimInventory.java

@@ -0,0 +1,66 @@
+package games.dmg.spigotquestboard;
+
+import java.util.ArrayList;
+import java.util.List;
+import java.util.Map;
+import org.bukkit.entity.Item;
+import org.bukkit.entity.Player;
+import org.bukkit.inventory.ItemStack;
+import org.bukkit.inventory.PlayerInventory;
+
+final class BukkitQuestClaimInventory implements QuestClaimInventory {
+    @Override
+    public PreparedClaim prepare(List<EscrowItem> items) {
+        List<ItemStack> stacks = items.stream().map(EscrowItem::toItemStack).toList();
+        return player -> deliver(player, stacks);
+    }
+
+    static Delivery deliver(Player player, List<ItemStack> stacks) {
+        PlayerInventory inventory = player.getInventory();
+        ItemStack[] snapshot = cloneContents(inventory.getStorageContents());
+        List<Item> drops = new ArrayList<>();
+        int overflow = 0;
+        try {
+            for (ItemStack stack : stacks) {
+                Map<Integer, ItemStack> leftovers = inventory.addItem(stack.clone());
+                for (ItemStack leftover : leftovers.values()) {
+                    Item drop = player.getWorld().dropItem(player.getLocation(), leftover.clone());
+                    drops.add(drop);
+                    drop.setOwner(player.getUniqueId());
+                    overflow += leftover.getAmount();
+                }
+            }
+        } catch (RuntimeException exception) {
+            inventory.setStorageContents(cloneContents(snapshot));
+            drops.forEach(Item::remove);
+            throw exception;
+        }
+        int deliveredOverflow = overflow;
+        return new Delivery() {
+            private boolean rolledBack;
+
+            @Override
+            public int overflowAmount() {
+                return deliveredOverflow;
+            }
+
+            @Override
+            public void rollback() {
+                if (rolledBack) {
+                    return;
+                }
+                inventory.setStorageContents(cloneContents(snapshot));
+                drops.forEach(Item::remove);
+                rolledBack = true;
+            }
+        };
+    }
+
+    private static ItemStack[] cloneContents(ItemStack[] contents) {
+        ItemStack[] copy = new ItemStack[contents.length];
+        for (int index = 0; index < contents.length; index++) {
+            copy[index] = contents[index] == null ? null : contents[index].clone();
+        }
+        return copy;
+    }
+}

src/main/java/games/dmg/spigotquestboard/BukkitQuestCompletionInventory.java

@@ -0,0 +1,92 @@
+package games.dmg.spigotquestboard;
+
+import java.util.ArrayList;
+import java.util.LinkedHashMap;
+import java.util.List;
+import java.util.Map;
+import java.util.Objects;
+import org.bukkit.Material;
+import org.bukkit.entity.Item;
+import org.bukkit.entity.Player;
+import org.bukkit.inventory.ItemStack;
+import org.bukkit.inventory.PlayerInventory;
+
+final class BukkitQuestCompletionInventory implements QuestCompletionInventory {
+    @Override
+    public RemovedDelivery remove(Player player, String materialName, int amount) {
+        Objects.requireNonNull(player, "player");
+        Material material = Objects.requireNonNull(Material.matchMaterial(materialName), "material");
+        PlayerInventory inventory = player.getInventory();
+        ItemStack[] contents = inventory.getStorageContents();
+        int available = 0;
+        for (ItemStack stack : contents) {
+            if (stack != null && stack.getType() == material) {
+                available += stack.getAmount();
+            }
+        }
+        if (available < amount) {
+            throw new IllegalArgumentException(
+                "You need exactly " + amount + " " + material.name()
+                    + " to complete this quest (you have " + available + ")."
+            );
+        }
+
+        Map<Integer, ItemStack> snapshots = new LinkedHashMap<>();
+        List<EscrowItem> removedItems = new ArrayList<>();
+        int remaining = amount;
+        for (int slot = 0; slot < contents.length && remaining > 0; slot++) {
+            ItemStack stack = contents[slot];
+            if (stack == null || stack.getType() != material) {
+                continue;
+            }
+            snapshots.put(slot, stack.clone());
+            int removedAmount = Math.min(stack.getAmount(), remaining);
+            ItemStack removed = stack.clone();
+            removed.setAmount(removedAmount);
+            removedItems.add(EscrowItem.fromItemStack(removed));
+            if (removedAmount == stack.getAmount()) {
+                inventory.clear(slot);
+            } else {
+                ItemStack reduced = stack.clone();
+                reduced.setAmount(stack.getAmount() - removedAmount);
+                inventory.setItem(slot, reduced);
+            }
+            remaining -= removedAmount;
+        }
+
+        return new RemovedDelivery() {
+            private boolean rolledBack;
+
+            @Override
+            public List<EscrowItem> items() {
+                return List.copyOf(removedItems);
+            }
+
+            @Override
+            public void rollback() {
+                if (rolledBack) {
+                    return;
+                }
+                snapshots.forEach(inventory::setItem);
+                rolledBack = true;
+            }
+        };
+    }
+
+    @Override
+    public PreparedReward prepare(List<EscrowItem> reward) {
+        List<ItemStack> stacks = reward.stream().map(EscrowItem::toItemStack).toList();
+        return player -> {
+            int overflow = 0;
+            for (ItemStack stack : stacks) {
+                Map<Integer, ItemStack> leftovers = player.getInventory().addItem(stack.clone());
+                for (ItemStack leftover : leftovers.values()) {
+                    Item dropped = player.getWorld().dropItem(player.getLocation(), leftover);
+                    dropped.setOwner(player.getUniqueId());
+                    overflow += leftover.getAmount();
+                }
+            }
+            return overflow;
+        };
+    }
+}

src/main/java/games/dmg/spigotquestboard/ClaimCollectionResult.java

@@ -0,0 +1,4 @@
+package games.dmg.spigotquestboard;
+
+record ClaimCollectionResult(int claimsCollected, int overflowItems) {
+}

src/main/java/games/dmg/spigotquestboard/EscrowItem.java

@@ -2,10 +2,17 @@ package games.dmg.spigotquestboard;
 
 import java.util.Base64;
 import java.util.Objects;
+import net.kyori.adventure.text.Component;
+import net.kyori.adventure.text.serializer.plain.PlainTextComponentSerializer;
 import org.bukkit.Material;
 import org.bukkit.inventory.ItemStack;
+import org.bukkit.inventory.meta.ItemMeta;
+
+record EscrowItem(String material, int amount, String serializedItem, String customName) {
+    EscrowItem(String material, int amount, String serializedItem) {
+        this(material, amount, serializedItem, null);
+    }
 
-record EscrowItem(String material, int amount, String serializedItem) {
     EscrowItem {
         Objects.requireNonNull(material, "material");
         material = material.trim().toUpperCase(java.util.Locale.ROOT);
@@ -18,24 +25,43 @@ record EscrowItem(String material, int amount, String serializedItem) {
         if (serializedItem != null && serializedItem.isBlank()) {
             throw new IllegalArgumentException("Serialized item must not be blank");
         }
+        customName = normalizeReadableName(customName);
     }
 
     static EscrowItem fromItemStack(ItemStack stack) {
         Objects.requireNonNull(stack, "stack");
-        if (stack.getType().isAir() || stack.getAmount() <= 0) {
+        if (isAir(stack.getType()) || stack.getAmount() <= 0) {
             throw new IllegalArgumentException("Reward stack must not be empty");
         }
         ItemStack snapshot = stack.clone();
         return new EscrowItem(
             snapshot.getType().name(), snapshot.getAmount(),
-            Base64.getEncoder().encodeToString(snapshot.serializeAsBytes())
+            Base64.getEncoder().encodeToString(snapshot.serializeAsBytes()),
+            readableCustomName(snapshot)
         );
     }
 
+    EscrowItem inferCustomName() {
+        if (customName != null || serializedItem == null) {
+            return this;
+        }
+        try {
+            String inferredName = readableCustomName(deserializeExactItem());
+            return inferredName == null
+                ? this : new EscrowItem(material, amount, serializedItem, inferredName);
+        } catch (RuntimeException | LinkageError exception) {
+            return this;
+        }
+    }
+
     ItemStack toItemStack() {
         if (serializedItem == null) {
             return new ItemStack(Objects.requireNonNull(Material.matchMaterial(material)), amount);
         }
+        return deserializeExactItem();
+    }
+
+    private ItemStack deserializeExactItem() {
         final ItemStack stack;
         try {
             stack = ItemStack.deserializeBytes(Base64.getDecoder().decode(serializedItem));
@@ -47,4 +73,34 @@ record EscrowItem(String material, int amount, String serializedItem) {
         }
         return stack;
     }
+
+    private static boolean isAir(Material material) {
+        return material == Material.AIR || material == Material.CAVE_AIR
+            || material == Material.VOID_AIR;
+    }
+
+    private static String readableCustomName(ItemStack stack) {
+        if (!stack.hasItemMeta()) {
+            return null;
+        }
+        ItemMeta metadata = stack.getItemMeta();
+        if (!metadata.hasCustomName()) {
+            return null;
+        }
+        Component name = metadata.customName();
+        if (name == null) {
+            return null;
+        }
+        return normalizeReadableName(
+            PlainTextComponentSerializer.plainText().serialize(name)
+        );
+    }
+
+    private static String normalizeReadableName(String name) {
+        if (name == null) {
+            return null;
+        }
+        String normalized = name.replaceAll("[\\p{Cntrl}\\s]+", " ").trim();
+        return normalized.isEmpty() ? null : normalized;
+    }
 }

src/main/java/games/dmg/spigotquestboard/IssuerNotification.java

@@ -0,0 +1,23 @@
+package games.dmg.spigotquestboard;
+
+import java.time.Instant;
+import java.util.Objects;
+import java.util.UUID;
+
+record IssuerNotification(
+    UUID id,
+    UUID questId,
+    UUID recipientId,
+    String message,
+    Instant createdAt
+) {
+    IssuerNotification {
+        Objects.requireNonNull(id, "id");
+        Objects.requireNonNull(questId, "questId");
+        Objects.requireNonNull(recipientId, "recipientId");
+        if (Objects.requireNonNull(message, "message").isBlank()) {
+            throw new IllegalArgumentException("Notification message must not be blank");
+        }
+        Objects.requireNonNull(createdAt, "createdAt");
+    }
+}

src/main/java/games/dmg/spigotquestboard/IssuerNotifier.java

@@ -0,0 +1,7 @@
+package games.dmg.spigotquestboard;
+
+import java.util.UUID;
+
+interface IssuerNotifier {
+    void notifyIfOnline(UUID issuerId);
+}

src/main/java/games/dmg/spigotquestboard/ItemMaterialCatalog.java

@@ -3,7 +3,7 @@ package games.dmg.spigotquestboard;
 import java.util.List;
 import java.util.Optional;
 
-interface BlockMaterialCatalog {
-    Optional<String> normalizeBlock(String input);
+interface ItemMaterialCatalog {
+    Optional<String> normalizeItem(String input);
     List<String> suggest(String prefix);
 }

src/main/java/games/dmg/spigotquestboard/PhysicalBoardCreationResult.java

@@ -0,0 +1,7 @@
+package games.dmg.spigotquestboard;
+
+enum PhysicalBoardCreationResult {
+    CREATED,
+    OBSTRUCTED,
+    ALREADY_REGISTERED
+}

src/main/java/games/dmg/spigotquestboard/PhysicalBoardCreator.java

@@ -0,0 +1,93 @@
+package games.dmg.spigotquestboard;
+
+import java.io.IOException;
+import java.util.ArrayList;
+import java.util.LinkedHashMap;
+import java.util.List;
+import java.util.Map;
+import java.util.Objects;
+import org.bukkit.block.Block;
+
+final class PhysicalBoardCreator {
+    interface WorldFactory {
+        PhysicalBoardWorld open(Block anchor);
+    }
+
+    private final BoardRegistry registry;
+    private final WorldFactory worlds;
+
+    PhysicalBoardCreator(BoardRegistry registry, WorldFactory worlds) {
+        this.registry = Objects.requireNonNull(registry, "registry");
+        this.worlds = Objects.requireNonNull(worlds, "worlds");
+    }
+
+    PhysicalBoardCreationResult create(Block anchorBlock, BoardFacing facing) throws IOException {
+        Objects.requireNonNull(anchorBlock, "anchorBlock");
+        BoardId anchor = BoardId.from(anchorBlock);
+        String worldName = anchorBlock.getWorld().getName();
+        PhysicalBoardPlan plan = PhysicalBoardPlan.create(anchor, facing);
+        PhysicalBoardWorld world = worlds.open(anchorBlock);
+
+        for (PhysicalBoardPlan.Placement placement : plan.placements()) {
+            if (!world.isEmpty(placement.location())) {
+                return PhysicalBoardCreationResult.OBSTRUCTED;
+            }
+        }
+        for (BoardId location : plan.interactionLocations()) {
+            if (registry.contains(location)) {
+                return PhysicalBoardCreationResult.ALREADY_REGISTERED;
+            }
+        }
+
+        Map<BoardId, Object> snapshots = new LinkedHashMap<>();
+        try {
+            for (PhysicalBoardPlan.Placement placement : plan.placements()) {
+                snapshots.put(placement.location(), world.snapshot(placement.location()));
+            }
+            for (PhysicalBoardPlan.Placement placement : plan.placements()) {
+                world.place(placement, facing);
+            }
+            List<RegisteredBoard> registrations = plan.interactionLocations().stream()
+                .map(location -> new RegisteredBoard(location, worldName))
+                .toList();
+            BoardRegistrationResult result = registry.registerAll(registrations);
+            if (result != BoardRegistrationResult.CREATED) {
+                rollback(world, snapshots, null);
+                return PhysicalBoardCreationResult.ALREADY_REGISTERED;
+            }
+            return PhysicalBoardCreationResult.CREATED;
+        } catch (RuntimeException | IOException exception) {
+            rollback(world, snapshots, exception);
+            if (exception instanceof IOException ioException) {
+                throw ioException;
+            }
+            throw new IOException("Could not generate physical quest board", exception);
+        }
+    }
+
+    private static void rollback(
+        PhysicalBoardWorld world, Map<BoardId, Object> snapshots, Throwable failure
+    ) throws IOException {
+        RuntimeException rollbackFailure = null;
+        List<Map.Entry<BoardId, Object>> entries = new ArrayList<>(snapshots.entrySet());
+        for (int index = entries.size() - 1; index >= 0; index--) {
+            Map.Entry<BoardId, Object> entry = entries.get(index);
+            try {
+                world.restore(entry.getKey(), entry.getValue());
+            } catch (RuntimeException exception) {
+                if (rollbackFailure == null) {
+                    rollbackFailure = exception;
+                } else {
+                    rollbackFailure.addSuppressed(exception);
+                }
+            }
+        }
+        if (rollbackFailure != null) {
+            if (failure != null) {
+                failure.addSuppressed(rollbackFailure);
+            } else {
+                throw new IOException("Could not fully restore physical quest board", rollbackFailure);
+            }
+        }
+    }
+}

src/main/java/games/dmg/spigotquestboard/PhysicalBoardPlan.java

@@ -0,0 +1,102 @@
+package games.dmg.spigotquestboard;
+
+import java.util.ArrayList;
+import java.util.LinkedHashSet;
+import java.util.List;
+import java.util.Objects;
+import java.util.Set;
+
+record PhysicalBoardPlan(
+    BoardFacing facing,
+    List<Placement> placements,
+    Set<BoardId> interactionLocations
+) {
+    PhysicalBoardPlan {
+        Objects.requireNonNull(facing, "facing");
+        placements = List.copyOf(Objects.requireNonNull(placements, "placements"));
+        interactionLocations = Set.copyOf(Objects.requireNonNull(
+            interactionLocations, "interactionLocations"
+        ));
+    }
+
+    static PhysicalBoardPlan create(BoardId anchor, BoardFacing facing) {
+        Objects.requireNonNull(anchor, "anchor");
+        Objects.requireNonNull(facing, "facing");
+        List<Placement> placements = new ArrayList<>(25);
+        Set<BoardId> interactions = new LinkedHashSet<>(17);
+
+        for (int height = 1; height <= 4; height++) {
+            for (int lateral = -2; lateral <= 2; lateral++) {
+                BoardId location = offset(anchor, facing, lateral, height, 0);
+                String material = Math.abs(lateral) == 2 ? "OAK_LOG" : "OAK_PLANKS";
+                placements.add(new Placement(location, material));
+                if ("OAK_PLANKS".equals(material)) {
+                    interactions.add(location);
+                }
+            }
+        }
+        for (int lateral = -1; lateral <= 1; lateral++) {
+            BoardId location = offset(anchor, facing, lateral, 2, 1);
+            placements.add(new Placement(
+                location, "OAK_WALL_SIGN", PhysicalBoardSignKind.DECORATIVE
+            ));
+            interactions.add(location);
+        }
+        addSign(
+            placements, interactions, offset(anchor, facing, 0, 3, 1),
+            PhysicalBoardSignKind.INSTRUCTION
+        );
+        addSign(
+            placements, interactions, offset(anchor, facing, 0, 4, 1),
+            PhysicalBoardSignKind.TITLE
+        );
+        return new PhysicalBoardPlan(facing, placements, interactions);
+    }
+
+    private static void addSign(
+        List<Placement> placements,
+        Set<BoardId> interactions,
+        BoardId location,
+        PhysicalBoardSignKind kind
+    ) {
+        placements.add(new Placement(location, "OAK_WALL_SIGN", kind));
+        interactions.add(location);
+    }
+
+    private static BoardId offset(
+        BoardId anchor, BoardFacing facing, int lateral, int vertical, int forward
+    ) {
+        return new BoardId(
+            anchor.worldId(),
+            anchor.x() + lateral * facing.rightX() + forward * facing.x(),
+            anchor.y() + vertical,
+            anchor.z() + lateral * facing.rightZ() + forward * facing.z()
+        );
+    }
+
+    record Placement(
+        BoardId location,
+        String material,
+        PhysicalBoardSignKind signKind
+    ) {
+        Placement {
+            Objects.requireNonNull(location, "location");
+            Objects.requireNonNull(material, "material");
+            if ("OAK_WALL_SIGN".equals(material) != (signKind != null)) {
+                throw new IllegalArgumentException("Only wall signs require sign metadata");
+            }
+        }
+
+        Placement(BoardId location, String material) {
+            this(
+                location,
+                material,
+                "OAK_WALL_SIGN".equals(material) ? PhysicalBoardSignKind.DECORATIVE : null
+            );
+        }
+
+        boolean sign() {
+            return signKind != null;
+        }
+    }
+}

src/main/java/games/dmg/spigotquestboard/PhysicalBoardSignKind.java

@@ -0,0 +1,7 @@
+package games.dmg.spigotquestboard;
+
+enum PhysicalBoardSignKind {
+    TITLE,
+    INSTRUCTION,
+    DECORATIVE
+}

src/main/java/games/dmg/spigotquestboard/PhysicalBoardUpgrader.java

@@ -0,0 +1,244 @@
+package games.dmg.spigotquestboard;
+
+import java.io.IOException;
+import java.util.ArrayList;
+import java.util.LinkedHashMap;
+import java.util.LinkedHashSet;
+import java.util.List;
+import java.util.Map;
+import java.util.Objects;
+import java.util.Set;
+import java.util.UUID;
+
+final class PhysicalBoardUpgrader {
+    interface WorldFactory {
+        PhysicalBoardWorld open(UUID worldId);
+    }
+
+    private record Candidate(BoardId anchor, BoardFacing facing, String worldName) { }
+    private record RelativeInteraction(int lateral, int height, int forward) { }
+
+    private static final List<RelativeInteraction> LEGACY_INTERACTIONS = legacyInteractions();
+
+    private final BoardRegistry registry;
+    private final WorldFactory worlds;
+
+    PhysicalBoardUpgrader(BoardRegistry registry, WorldFactory worlds) {
+        this.registry = Objects.requireNonNull(registry, "registry");
+        this.worlds = Objects.requireNonNull(worlds, "worlds");
+    }
+
+    int upgrade() throws IOException {
+        int upgraded = 0;
+        Map<BoardId, RegisteredBoard> registered = registry.registeredBoards();
+        for (Candidate candidate : candidates(registered)) {
+            boolean legacy = hasLegacyRegistrations(candidate, registered);
+            boolean full = hasFullRegistrations(candidate, registered);
+            if (!legacy && !full) {
+                continue;
+            }
+            PhysicalBoardWorld world = worlds.open(candidate.anchor().worldId());
+            if (world == null) {
+                continue;
+            }
+            if (legacy && isLegacyBoard(candidate, world) && upgradeLegacy(candidate, world)) {
+                upgraded++;
+                registered = registry.registeredBoards();
+            } else if (full && isNonGlowingFullBoard(candidate, world)) {
+                refreshReadableSigns(candidate, world);
+                upgraded++;
+            }
+        }
+        return upgraded;
+    }
+
+    private static boolean hasLegacyRegistrations(
+        Candidate candidate, Map<BoardId, RegisteredBoard> registered
+    ) {
+        PhysicalBoardPlan plan = PhysicalBoardPlan.create(candidate.anchor(), candidate.facing());
+        for (BoardId location : legacyInteractionLocations(plan)) {
+            RegisteredBoard board = registered.get(location);
+            if (board == null || !candidate.worldName().equals(board.worldName())) {
+                return false;
+            }
+        }
+        return newSigns(plan).stream().noneMatch(sign ->
+            registered.containsKey(sign.location())
+        );
+    }
+
+    private static boolean hasFullRegistrations(
+        Candidate candidate, Map<BoardId, RegisteredBoard> registered
+    ) {
+        PhysicalBoardPlan plan = PhysicalBoardPlan.create(candidate.anchor(), candidate.facing());
+        for (BoardId location : plan.interactionLocations()) {
+            RegisteredBoard board = registered.get(location);
+            if (board == null || !candidate.worldName().equals(board.worldName())) {
+                return false;
+            }
+        }
+        return true;
+    }
+
+    private boolean isLegacyBoard(Candidate candidate, PhysicalBoardWorld world) {
+        PhysicalBoardPlan plan = PhysicalBoardPlan.create(candidate.anchor(), candidate.facing());
+        for (PhysicalBoardPlan.Placement placement : legacyPlacements(plan)) {
+            if (!world.matches(placement, candidate.facing())) {
+                return false;
+            }
+        }
+        for (PhysicalBoardPlan.Placement placement : newSigns(plan)) {
+            if (!world.isEmpty(placement.location())) {
+                return false;
+            }
+        }
+        return true;
+    }
+
+    private boolean isNonGlowingFullBoard(Candidate candidate, PhysicalBoardWorld world) {
+        PhysicalBoardPlan plan = PhysicalBoardPlan.create(candidate.anchor(), candidate.facing());
+        for (PhysicalBoardPlan.Placement placement : plan.placements()) {
+            boolean matches = placement.sign()
+                ? world.matches(placement, candidate.facing(), false)
+                : world.matches(placement, candidate.facing());
+            if (!matches) {
+                return false;
+            }
+        }
+        return true;
+    }
+
+    private boolean upgradeLegacy(Candidate candidate, PhysicalBoardWorld world) throws IOException {
+        List<PhysicalBoardPlan.Placement> signs = readableSigns(
+            PhysicalBoardPlan.create(candidate.anchor(), candidate.facing())
+        );
+        Map<BoardId, Object> snapshots = new LinkedHashMap<>();
+        try {
+            for (PhysicalBoardPlan.Placement sign : signs) {
+                snapshots.put(sign.location(), world.snapshot(sign.location()));
+            }
+            for (PhysicalBoardPlan.Placement sign : signs) {
+                world.place(sign, candidate.facing());
+            }
+            List<RegisteredBoard> additions = signs.stream()
+                .map(sign -> new RegisteredBoard(sign.location(), candidate.worldName()))
+                .toList();
+            if (registry.registerAll(additions) != BoardRegistrationResult.CREATED) {
+                rollback(world, snapshots, null);
+                return false;
+            }
+            return true;
+        } catch (RuntimeException | IOException exception) {
+            rollback(world, snapshots, exception);
+            if (exception instanceof IOException ioException) {
+                throw ioException;
+            }
+            throw new IOException("Could not upgrade physical quest board", exception);
+        }
+    }
+
+    private static Set<Candidate> candidates(Map<BoardId, RegisteredBoard> registered) {
+        Set<Candidate> candidates = new LinkedHashSet<>();
+        for (RegisteredBoard board : registered.values()) {
+            for (BoardFacing facing : BoardFacing.values()) {
+                for (RelativeInteraction relative : LEGACY_INTERACTIONS) {
+                    BoardId location = board.id();
+                    candidates.add(new Candidate(new BoardId(
+                        location.worldId(),
+                        location.x() - relative.lateral() * facing.rightX()
+                            - relative.forward() * facing.x(),
+                        location.y() - relative.height(),
+                        location.z() - relative.lateral() * facing.rightZ()
+                            - relative.forward() * facing.z()
+                    ), facing, board.worldName()));
+                }
+            }
+        }
+        return candidates;
+    }
+
+    private static List<RelativeInteraction> legacyInteractions() {
+        List<RelativeInteraction> interactions = new ArrayList<>(15);
+        for (int height = 1; height <= 4; height++) {
+            for (int lateral = -1; lateral <= 1; lateral++) {
+                interactions.add(new RelativeInteraction(lateral, height, 0));
+            }
+        }
+        for (int lateral = -1; lateral <= 1; lateral++) {
+            interactions.add(new RelativeInteraction(lateral, 2, 1));
+        }
+        return List.copyOf(interactions);
+    }
+
+    private static List<PhysicalBoardPlan.Placement> legacyPlacements(PhysicalBoardPlan plan) {
+        return plan.placements().stream().filter(placement ->
+            !placement.sign() || placement.signKind() == PhysicalBoardSignKind.DECORATIVE
+        ).toList();
+    }
+
+    private static Set<BoardId> legacyInteractionLocations(PhysicalBoardPlan plan) {
+        Set<BoardId> locations = new LinkedHashSet<>();
+        for (PhysicalBoardPlan.Placement placement : legacyPlacements(plan)) {
+            if ("OAK_PLANKS".equals(placement.material()) || placement.sign()) {
+                locations.add(placement.location());
+            }
+        }
+        return Set.copyOf(locations);
+    }
+
+    private void refreshReadableSigns(Candidate candidate, PhysicalBoardWorld world)
+        throws IOException {
+        List<PhysicalBoardPlan.Placement> signs = readableSigns(
+            PhysicalBoardPlan.create(candidate.anchor(), candidate.facing())
+        );
+        Map<BoardId, Object> snapshots = new LinkedHashMap<>();
+        try {
+            for (PhysicalBoardPlan.Placement sign : signs) {
+                snapshots.put(sign.location(), world.snapshot(sign.location()));
+            }
+            for (PhysicalBoardPlan.Placement sign : signs) {
+                world.place(sign, candidate.facing());
+            }
+        } catch (RuntimeException exception) {
+            rollback(world, snapshots, exception);
+            throw new IOException("Could not refresh physical quest-board signs", exception);
+        }
+    }
+
+    private static List<PhysicalBoardPlan.Placement> newSigns(PhysicalBoardPlan plan) {
+        return readableSigns(plan);
+    }
+
+    private static List<PhysicalBoardPlan.Placement> readableSigns(PhysicalBoardPlan plan) {
+        return plan.placements().stream().filter(placement ->
+            placement.signKind() == PhysicalBoardSignKind.TITLE
+                || placement.signKind() == PhysicalBoardSignKind.INSTRUCTION
+        ).toList();
+    }
+
+    private static void rollback(
+        PhysicalBoardWorld world, Map<BoardId, Object> snapshots, Throwable failure
+    ) throws IOException {
+        RuntimeException rollbackFailure = null;
+        List<Map.Entry<BoardId, Object>> entries = new ArrayList<>(snapshots.entrySet());
+        for (int index = entries.size() - 1; index >= 0; index--) {
+            Map.Entry<BoardId, Object> entry = entries.get(index);
+            try {
+                world.restore(entry.getKey(), entry.getValue());
+            } catch (RuntimeException exception) {
+                if (rollbackFailure == null) {
+                    rollbackFailure = exception;
+                } else {
+                    rollbackFailure.addSuppressed(exception);
+                }
+            }
+        }
+        if (rollbackFailure != null) {
+            if (failure != null) {
+                failure.addSuppressed(rollbackFailure);
+            } else {
+                throw new IOException("Could not restore physical board upgrade", rollbackFailure);
+            }
+        }
+    }
+}

src/main/java/games/dmg/spigotquestboard/PhysicalBoardWorld.java

@@ -0,0 +1,21 @@
+package games.dmg.spigotquestboard;
+
+interface PhysicalBoardWorld {
+    boolean isEmpty(BoardId location);
+
+    Object snapshot(BoardId location);
+
+    void place(PhysicalBoardPlan.Placement placement, BoardFacing facing);
+
+    default boolean matches(PhysicalBoardPlan.Placement placement, BoardFacing facing) {
+        return false;
+    }
+
+    default boolean matches(
+        PhysicalBoardPlan.Placement placement, BoardFacing facing, boolean glowingText
+    ) {
+        return false;
+    }
+
+    void restore(BoardId location, Object snapshot);
+}

src/main/java/games/dmg/spigotquestboard/PlayerCommandSettings.java

@@ -0,0 +1,23 @@
+package games.dmg.spigotquestboard;
+
+import java.io.IOException;
+import java.util.Objects;
+
+final class PlayerCommandSettings {
+    private final PlayerCommandSettingsRepository repository;
+    private boolean enabled;
+
+    PlayerCommandSettings(PlayerCommandSettingsRepository repository) throws IOException {
+        this.repository = Objects.requireNonNull(repository, "repository");
+        enabled = repository.loadEnabled();
+    }
+
+    boolean enabled() {
+        return enabled;
+    }
+
+    void setEnabled(boolean enabled) throws IOException {
+        repository.saveEnabled(enabled);
+        this.enabled = enabled;
+    }
+}

src/main/java/games/dmg/spigotquestboard/PlayerCommandSettingsRepository.java

@@ -0,0 +1,8 @@
+package games.dmg.spigotquestboard;
+
+import java.io.IOException;
+
+interface PlayerCommandSettingsRepository {
+    boolean loadEnabled() throws IOException;
+    void saveEnabled(boolean enabled) throws IOException;
+}

src/main/java/games/dmg/spigotquestboard/QuestAdminCommand.java

@@ -1,19 +1,40 @@
 package games.dmg.spigotquestboard;
 
 import java.io.IOException;
+import java.util.List;
+import java.util.Locale;
 import java.util.Objects;
 import org.bukkit.block.Block;
 import org.bukkit.command.Command;
 import org.bukkit.command.CommandExecutor;
 import org.bukkit.command.CommandSender;
+import org.bukkit.command.TabCompleter;
 import org.bukkit.entity.Player;
 
-final class QuestAdminCommand implements CommandExecutor {
+final class QuestAdminCommand implements CommandExecutor, TabCompleter {
     private static final String PERMISSION = "spigotquestboard.admin";
     private final BoardRegistry registry;
+    private final PlayerCommandSettings playerCommands;
+    private final PhysicalBoardCreator physicalBoards;
 
-    QuestAdminCommand(BoardRegistry registry) {
+    QuestAdminCommand(BoardRegistry registry, PlayerCommandSettings playerCommands) {
+        this(
+            registry,
+            playerCommands,
+            new PhysicalBoardCreator(
+                registry, anchor -> new BukkitPhysicalBoardWorld(anchor.getWorld())
+            )
+        );
+    }
+
+    QuestAdminCommand(
+        BoardRegistry registry,
+        PlayerCommandSettings playerCommands,
+        PhysicalBoardCreator physicalBoards
+    ) {
         this.registry = Objects.requireNonNull(registry, "registry");
+        this.playerCommands = Objects.requireNonNull(playerCommands, "playerCommands");
+        this.physicalBoards = Objects.requireNonNull(physicalBoards, "physicalBoards");
     }
 
     @Override
@@ -24,18 +45,56 @@ final class QuestAdminCommand implements CommandExecutor {
             sender.sendMessage("You do not have permission to administer quest boards.");
             return true;
         }
-        if (arguments.length != 1 || !"createboard".equalsIgnoreCase(arguments[0])) {
-            sender.sendMessage("Usage: /questadmin createboard");
+        if (arguments.length == 2 && "commands".equalsIgnoreCase(arguments[0])) {
+            return updatePlayerCommands(sender, arguments[1]);
+        }
+        if (arguments.length == 1 && "createboard".equalsIgnoreCase(arguments[0])) {
+            createBoard(sender);
             return true;
         }
+        if (arguments.length == 2
+            && "createboard".equalsIgnoreCase(arguments[0])
+            && "physical".equalsIgnoreCase(arguments[1])) {
+            createPhysicalBoard(sender);
+            return true;
+        }
+        sender.sendMessage(
+            "Usage: /questadmin createboard [physical] | /questadmin commands enable|disable"
+        );
+        return true;
+    }
+
+    private boolean updatePlayerCommands(CommandSender sender, String action) {
+        final boolean enabled;
+        if ("enable".equalsIgnoreCase(action)) {
+            enabled = true;
+        } else if ("disable".equalsIgnoreCase(action)) {
+            enabled = false;
+        } else {
+            sender.sendMessage("Usage: /questadmin commands enable|disable");
+            return true;
+        }
+        try {
+            playerCommands.setEnabled(enabled);
+            sender.sendMessage("Player quest commands " + (enabled ? "enabled." : "disabled."));
+        } catch (IOException exception) {
+            sender.sendMessage(
+                "Player command setting could not be saved. Player quest commands remain "
+                    + (playerCommands.enabled() ? "enabled." : "disabled.")
+            );
+        }
+        return true;
+    }
+
+    private void createBoard(CommandSender sender) {
         if (!(sender instanceof Player player)) {
             sender.sendMessage("A player must target the quest board block.");
-            return true;
+            return;
         }
         Block target = player.getTargetBlockExact(5);
         if (target == null) {
             sender.sendMessage("Target a physical block within five blocks.");
-            return true;
+            return;
         }
         try {
             BoardRegistrationResult result = registry.register(RegisteredBoard.from(target));
@@ -45,6 +104,61 @@ final class QuestAdminCommand implements CommandExecutor {
         } catch (IOException exception) {
             sender.sendMessage("The quest board could not be saved. No board was created.");
         }
-        return true;
+    }
+
+    private void createPhysicalBoard(CommandSender sender) {
+        if (!(sender instanceof Player player)) {
+            sender.sendMessage("A player must target the ground anchor block.");
+            return;
+        }
+        Block target = player.getTargetBlockExact(5);
+        if (target == null) {
+            sender.sendMessage("Target a ground anchor within five blocks.");
+            return;
+        }
+        try {
+            PhysicalBoardCreationResult result = physicalBoards.create(
+                target, BoardFacing.towardPlayer(player.getFacing())
+            );
+            switch (result) {
+                case CREATED -> sender.sendMessage("Physical quest board created.");
+                case OBSTRUCTED -> sender.sendMessage(
+                    "The physical quest board needs 23 empty placement blocks."
+                );
+                case ALREADY_REGISTERED -> sender.sendMessage(
+                    "A physical quest-board interaction location is already registered."
+                );
+            }
+        } catch (IOException | IllegalArgumentException exception) {
+            sender.sendMessage(
+                "The physical quest board could not be created. All changed blocks were restored."
+            );
+        }
+    }
+
+    @Override
+    public List<String> onTabComplete(
+        CommandSender sender, Command command, String alias, String[] arguments
+    ) {
+        if (!sender.hasPermission(PERMISSION)) {
+            return List.of();
+        }
+        if (arguments.length == 1) {
+            return startsWith(List.of("createboard", "commands"), arguments[0]);
+        }
+        if (arguments.length == 2 && "commands".equalsIgnoreCase(arguments[0])) {
+            return startsWith(List.of("enable", "disable"), arguments[1]);
+        }
+        if (arguments.length == 2 && "createboard".equalsIgnoreCase(arguments[0])) {
+            return startsWith(List.of("physical"), arguments[1]);
+        }
+        return List.of();
+    }
+
+    private static List<String> startsWith(List<String> candidates, String prefix) {
+        String normalized = prefix.toLowerCase(Locale.ROOT);
+        return candidates.stream()
+            .filter(candidate -> candidate.startsWith(normalized))
+            .toList();
     }
 }

src/main/java/games/dmg/spigotquestboard/QuestBoardDialogSpec.java

@@ -0,0 +1,87 @@
+package games.dmg.spigotquestboard;
+
+import java.util.List;
+import java.util.Objects;
+
+/** A server-independent description of the quest-board dialog hierarchy. */
+record QuestBoardDialogSpec(
+    int maximumBodyWidth,
+    Screen dashboard,
+    Screen browse,
+    Screen create,
+    Screen claims,
+    List<QuestEntry> questEntries
+) {
+    QuestBoardDialogSpec {
+        if (maximumBodyWidth <= 0) {
+            throw new IllegalArgumentException("Maximum body width must be positive");
+        }
+        Objects.requireNonNull(dashboard, "dashboard");
+        Objects.requireNonNull(browse, "browse");
+        Objects.requireNonNull(create, "create");
+        Objects.requireNonNull(claims, "claims");
+        questEntries = List.copyOf(Objects.requireNonNull(questEntries, "questEntries"));
+    }
+
+    List<String> dashboardActions() {
+        return dashboard.actions().stream().map(Action::label).toList();
+    }
+
+    record Screen(
+        String title,
+        String externalTitle,
+        String message,
+        List<Action> actions,
+        List<Input> inputs,
+        boolean hasBackAction
+    ) {
+        Screen {
+            Objects.requireNonNull(title, "title");
+            Objects.requireNonNull(externalTitle, "externalTitle");
+            Objects.requireNonNull(message, "message");
+            actions = List.copyOf(Objects.requireNonNull(actions, "actions"));
+            inputs = List.copyOf(Objects.requireNonNull(inputs, "inputs"));
+        }
+    }
+
+    record QuestEntry(
+        String title,
+        String message,
+        List<Action> actions,
+        boolean hasBackAction
+    ) {
+        QuestEntry {
+            Objects.requireNonNull(title, "title");
+            Objects.requireNonNull(message, "message");
+            actions = List.copyOf(Objects.requireNonNull(actions, "actions"));
+        }
+    }
+
+    record Action(String label, Route route, String questId) {
+        Action {
+            Objects.requireNonNull(label, "label");
+            Objects.requireNonNull(route, "route");
+        }
+    }
+
+    record Input(String key, String label, String initial, int maximumLength) {
+        Input {
+            Objects.requireNonNull(key, "key");
+            Objects.requireNonNull(label, "label");
+            Objects.requireNonNull(initial, "initial");
+            if (maximumLength <= 0) {
+                throw new IllegalArgumentException("Maximum input length must be positive");
+            }
+        }
+    }
+
+    enum Route {
+        OPEN_BROWSE,
+        OPEN_CREATE,
+        OPEN_CLAIMS,
+        SUBMIT_CREATE,
+        COMPLETE,
+        CANCEL,
+        COLLECT
+    }
+}

src/main/java/games/dmg/spigotquestboard/QuestBoardDialogUi.java

@@ -1,12 +1,14 @@
 package games.dmg.spigotquestboard;
 
 import io.papermc.paper.dialog.Dialog;
+import io.papermc.paper.registry.RegistryKey;
 import io.papermc.paper.registry.data.dialog.ActionButton;
 import io.papermc.paper.registry.data.dialog.DialogBase;
 import io.papermc.paper.registry.data.dialog.action.DialogAction;
 import io.papermc.paper.registry.data.dialog.body.DialogBody;
 import io.papermc.paper.registry.data.dialog.input.DialogInput;
 import io.papermc.paper.registry.data.dialog.type.DialogType;
+import io.papermc.paper.registry.set.RegistrySet;
 import java.io.IOException;
 import java.time.Clock;
 import java.time.Duration;
@@ -17,21 +19,185 @@ import net.kyori.adventure.text.event.ClickCallback;
 import org.bukkit.entity.Player;
 
 final class QuestBoardDialogUi implements QuestBoardUi {
+    private static final int DIALOG_WIDTH = 420;
+    private static final ClickCallback.Options CALLBACK_OPTIONS = ClickCallback.Options.builder()
+        .uses(1)
+        .lifetime(Duration.ofMinutes(10))
+        .build();
+
     private final QuestCreationGateway creator;
     private final QuestBrowser browser;
+    private final QuestCompletionGateway completer;
+    private final QuestCancellationGateway canceller;
+    private final QuestClaimGateway claimant;
     private final Clock clock;
 
     QuestBoardDialogUi(QuestCreationGateway creator, QuestBrowser browser, Clock clock) {
+        this(creator, browser, null, null, null, clock);
+    }
+
+    QuestBoardDialogUi(
+        QuestCreationGateway creator,
+        QuestBrowser browser,
+        QuestCompletionGateway completer,
+        Clock clock
+    ) {
+        this(creator, browser, completer, null, null, clock);
+    }
+
+    QuestBoardDialogUi(
+        QuestCreationGateway creator,
+        QuestBrowser browser,
+        QuestCompletionGateway completer,
+        QuestCancellationGateway canceller,
+        Clock clock
+    ) {
+        this(creator, browser, completer, canceller, null, clock);
+    }
+
+    QuestBoardDialogUi(
+        QuestCreationGateway creator,
+        QuestBrowser browser,
+        QuestCompletionGateway completer,
+        QuestCancellationGateway canceller,
+        QuestClaimGateway claimant,
+        Clock clock
+    ) {
         this.creator = Objects.requireNonNull(creator, "creator");
         this.browser = Objects.requireNonNull(browser, "browser");
+        this.completer = completer;
+        this.canceller = canceller;
+        this.claimant = claimant;
         this.clock = Objects.requireNonNull(clock, "clock");
     }
 
     @Override
     public void open(Player player) {
+        Objects.requireNonNull(player, "player");
+        player.showDialog(renderDashboard(specification(player), player));
+    }
+
+    QuestBoardDialogSpec specification(Player player) {
+        Objects.requireNonNull(player, "player");
+        java.time.Instant now = clock.instant();
+        List<QuestBoardDialogSpec.QuestEntry> entries = browser.activeQuests(now).stream()
+            .map(quest -> questEntry(quest, player, now))
+            .toList();
+        List<QuestBoardDialogSpec.Action> dashboardActions = List.of(
+            action("Browse quests", QuestBoardDialogSpec.Route.OPEN_BROWSE),
+            action("Create quest", QuestBoardDialogSpec.Route.OPEN_CREATE),
+            action("Pending claims", QuestBoardDialogSpec.Route.OPEN_CLAIMS)
+        );
+        QuestBoardDialogSpec.Screen dashboard = new QuestBoardDialogSpec.Screen(
+            "Quest Board",
+            "Quest Board",
+            "Choose what you want to do.",
+            dashboardActions,
+            List.of(),
+            false
+        );
+        QuestBoardDialogSpec.Screen browse = new QuestBoardDialogSpec.Screen(
+            "Browse Quests",
+            "Browse quests",
+            entries.isEmpty()
+                ? "No active quests."
+                : "Select a quest to view its request, reward, issuer, and time remaining.",
+            List.of(),
+            List.of(),
+            true
+        );
+        QuestBoardDialogSpec.Screen create = new QuestBoardDialogSpec.Screen(
+            "Create Quest",
+            "Create quest",
+            "Hold the reward in your main hand. The entire exact stack, including all item "
+                + "metadata, is escrowed only if the quest saves successfully.",
+            List.of(action("Create quest", QuestBoardDialogSpec.Route.SUBMIT_CREATE)),
+            List.of(
+                new QuestBoardDialogSpec.Input("requested_material", "Requested item", "", 64),
+                new QuestBoardDialogSpec.Input("requested_quantity", "Quantity", "64", 10)
+            ),
+            true
+        );
+        QuestBoardDialogSpec.Screen claims = new QuestBoardDialogSpec.Screen(
+            "Pending Claims",
+            "Pending claims",
+            claimListingText(player),
+            claimant == null
+                ? List.of()
+                : List.of(action("Collect pending claims", QuestBoardDialogSpec.Route.COLLECT)),
+            List.of(),
+            true
+        );
+        return new QuestBoardDialogSpec(
+            DIALOG_WIDTH, dashboard, browse, create, claims, entries
+        );
+    }
+
+    private QuestBoardDialogSpec.QuestEntry questEntry(
+        Quest quest,
+        Player player,
+        java.time.Instant now
+    ) {
+        List<QuestBoardDialogSpec.Action> actions = new java.util.ArrayList<>();
+        if (completer != null) {
+            actions.add(new QuestBoardDialogSpec.Action(
+                "Complete quest", QuestBoardDialogSpec.Route.COMPLETE, quest.id().toString()
+            ));
+        }
+        if (canceller != null && quest.issuerId().equals(player.getUniqueId())) {
+            actions.add(new QuestBoardDialogSpec.Action(
+                "Cancel quest", QuestBoardDialogSpec.Route.CANCEL, quest.id().toString()
+            ));
+        }
+        return new QuestBoardDialogSpec.QuestEntry(
+            quest.requestedAmount() + " × " + quest.requestedMaterial(),
+            QuestListingFormatter.format(quest, now),
+            actions,
+            true
+        );
+    }
+
+    private static QuestBoardDialogSpec.Action action(
+        String label,
+        QuestBoardDialogSpec.Route route
+    ) {
+        return new QuestBoardDialogSpec.Action(label, route, null);
+    }
+
+    private Dialog renderDashboard(QuestBoardDialogSpec specification, Player player) {
+        List<Dialog> screens = List.of(
+            renderBrowse(specification, player),
+            renderCreate(specification, player),
+            renderClaims(specification, player)
+        );
+        return dialog(
+            specification.dashboard(),
+            DialogType.dialogList(
+                RegistrySet.valueSet(RegistryKey.DIALOG, screens), null, 1, 260
+            )
+        );
+    }
+
+    private Dialog renderBrowse(QuestBoardDialogSpec specification, Player player) {
+        ActionButton back = backToDashboard(player);
+        if (specification.questEntries().isEmpty()) {
+            return dialog(specification.browse(), DialogType.notice(back));
+        }
+        List<Dialog> quests = specification.questEntries().stream()
+            .map(entry -> renderQuest(entry, player))
+            .toList();
+        return dialog(
+            specification.browse(),
+            DialogType.dialogList(
+                RegistrySet.valueSet(RegistryKey.DIALOG, quests), back, 1, 260
+            )
+        );
+    }
+
+    private Dialog renderCreate(QuestBoardDialogSpec specification, Player player) {
         ActionButton create = ActionButton.builder(Component.text("Create quest"))
             .tooltip(Component.text("Escrow your held stack and publish this quest"))
-            .width(150)
+            .width(180)
             .action(DialogAction.customClick((response, audience) -> {
                 if (audience instanceof Player respondingPlayer) {
                     submit(
@@ -40,36 +206,111 @@ final class QuestBoardDialogUi implements QuestBoardUi {
                         response.getText("requested_quantity")
                     );
                 }
-            }, ClickCallback.Options.builder()
-                .uses(1)
-                .lifetime(Duration.ofMinutes(10))
-                .build()))
+            }, CALLBACK_OPTIONS))
             .build();
-        String listing = listingText();
-        DialogBase base = DialogBase.builder(Component.text("Quest Board"))
-            .externalTitle(Component.text("Quest Board — Active quests and create"))
-            .body(List.of(DialogBody.plainMessage(Component.text(
-                "ACTIVE QUESTS\n" + listing + "\n\nCREATE A QUEST\n"
-                    + "Hold the reward in your main hand. The entire exact stack, including all item metadata, "
-                    + "will be removed and held in escrow only if this quest saves successfully."
-            ), 800)))
-            .inputs(List.of(
-                DialogInput.text("requested_material", Component.text("Requested block"))
-                    .initial("")
-                    .maxLength(64)
-                    .build(),
-                DialogInput.text("requested_quantity", Component.text("Quantity"))
-                    .initial("64")
-                    .maxLength(10)
-                    .build()
-            ))
+        return dialog(
+            specification.create(),
+            DialogType.multiAction(List.of(create), backToDashboard(player), 1)
+        );
+    }
+
+    private Dialog renderClaims(QuestBoardDialogSpec specification, Player player) {
+        ActionButton back = backToDashboard(player);
+        if (claimant == null) {
+            return dialog(specification.claims(), DialogType.notice(back));
+        }
+        ActionButton collect = callbackButton(
+            "Collect pending claims",
+            "Collect delivered items and returned rewards",
+            250,
+            respondingPlayer -> submitClaim(respondingPlayer)
+        );
+        return dialog(
+            specification.claims(), DialogType.multiAction(List.of(collect), back, 1)
+        );
+    }
+
+    private Dialog renderQuest(QuestBoardDialogSpec.QuestEntry entry, Player player) {
+        QuestBoardDialogSpec.Screen screen = new QuestBoardDialogSpec.Screen(
+            entry.title(), entry.title(), entry.message(), entry.actions(), List.of(), true
+        );
+        ActionButton back = backToBrowse(player);
+        List<ActionButton> actions = entry.actions().stream()
+            .map(action -> renderQuestAction(action))
+            .toList();
+        return dialog(
+            screen,
+            actions.isEmpty() ? DialogType.notice(back) : DialogType.multiAction(actions, back, 1)
+        );
+    }
+
+    private ActionButton renderQuestAction(QuestBoardDialogSpec.Action action) {
+        return switch (action.route()) {
+            case COMPLETE -> callbackButton(
+                action.label(), "Deliver the requested items", 180,
+                player -> submitCompletion(player, action.questId())
+            );
+            case CANCEL -> callbackButton(
+                action.label(), "Return the escrowed reward to pending claims", 180,
+                player -> submitCancellation(player, action.questId())
+            );
+            default -> throw new IllegalArgumentException("Unsupported quest action route");
+        };
+    }
+
+    private Dialog dialog(QuestBoardDialogSpec.Screen screen, DialogType type) {
+        DialogBase.Builder base = DialogBase.builder(Component.text(screen.title()))
+            .externalTitle(Component.text(screen.externalTitle()))
+            .body(List.of(DialogBody.plainMessage(Component.text(screen.message()), DIALOG_WIDTH)))
             .canCloseWithEscape(true)
             .pause(false)
-            .afterAction(DialogBase.DialogAfterAction.CLOSE)
+            .afterAction(DialogBase.DialogAfterAction.CLOSE);
+        if (!screen.inputs().isEmpty()) {
+            base.inputs(screen.inputs().stream().map(input -> DialogInput.text(
+                    input.key(), Component.text(input.label())
+                )
+                .initial(input.initial())
+                .maxLength(input.maximumLength())
+                .build()).toList());
+        }
+        DialogBase builtBase = base.build();
+        return Dialog.create(factory -> factory.empty().base(builtBase).type(type));
+    }
+
+    private ActionButton backToDashboard(Player player) {
+        return callbackButton(
+            "Back", "Return to the quest-board dashboard", 120,
+            respondingPlayer -> respondingPlayer.showDialog(
+                renderDashboard(specification(respondingPlayer), respondingPlayer)
+            )
+        );
+    }
+
+    private ActionButton backToBrowse(Player player) {
+        return callbackButton(
+            "Back", "Return to active quests", 120,
+            respondingPlayer -> {
+                QuestBoardDialogSpec current = specification(respondingPlayer);
+                respondingPlayer.showDialog(renderBrowse(current, respondingPlayer));
+            }
+        );
+    }
+
+    private ActionButton callbackButton(
+        String label,
+        String tooltip,
+        int width,
+        java.util.function.Consumer<Player> callback
+    ) {
+        return ActionButton.builder(Component.text(label))
+            .tooltip(Component.text(tooltip))
+            .width(width)
+            .action(DialogAction.customClick((response, audience) -> {
+                if (audience instanceof Player respondingPlayer) {
+                    callback.accept(respondingPlayer);
+                }
+            }, CALLBACK_OPTIONS))
             .build();
-        player.showDialog(Dialog.create(factory -> factory.empty()
-            .base(base)
-            .type(DialogType.notice(create))));
     }
 
     String listingText() {
@@ -77,6 +318,75 @@ final class QuestBoardDialogUi implements QuestBoardUi {
         return QuestListingFormatter.formatAll(browser.activeQuests(now), now);
     }
 
+    String claimListingText(Player player) {
+        if (claimant == null) {
+            return "Claim collection is unavailable.";
+        }
+        List<QuestClaim> claims = claimant.pendingClaims(player);
+        if (claims.isEmpty()) {
+            return "No pending claims.";
+        }
+        return claims.stream().map(claim -> {
+            String kind = claim.type() == QuestClaimType.DELIVERED_BLOCKS
+                ? "DELIVERED ITEMS" : "RETURNED REWARD (" + claim.source().name() + ")";
+            String items = claim.items().stream()
+                .map(item -> item.amount() + " " + item.material())
+                .reduce((left, right) -> left + ", " + right)
+                .orElseThrow();
+            return kind + " — " + items + " — quest " + claim.questId();
+        }).reduce((left, right) -> left + "\n" + right).orElseThrow();
+    }
+
+    List<String> cancellableQuestIds(Player player) {
+        return browser.cancellableQuestIds(player.getUniqueId(), clock.instant());
+    }
+
+    void submitCancellation(Player player, String questId) {
+        if (canceller == null) {
+            player.sendMessage("Quest cancellation is unavailable.");
+            return;
+        }
+        try {
+            canceller.cancel(player, questId, clock.instant());
+        } catch (IllegalArgumentException | IllegalStateException exception) {
+            player.sendMessage(exception.getMessage());
+        } catch (IOException exception) {
+            player.sendMessage(
+                "The quest could not be saved. It remains active and its reward remains escrowed."
+            );
+        }
+    }
+
+    void submitClaim(Player player) {
+        if (claimant == null) {
+            player.sendMessage("Quest claims are unavailable.");
+            return;
+        }
+        try {
+            claimant.collect(player);
+        } catch (IOException | RuntimeException exception) {
+            player.sendMessage(
+                "Your claim could not be collected safely. It remains pending; please try again."
+            );
+        }
+    }
+
+    void submitCompletion(Player player, String questId) {
+        if (completer == null) {
+            player.sendMessage("Quest completion is unavailable.");
+            return;
+        }
+        try {
+            completer.complete(player, questId, clock.instant());
+        } catch (IllegalArgumentException | IllegalStateException exception) {
+            player.sendMessage(exception.getMessage());
+        } catch (IOException exception) {
+            player.sendMessage(
+                "The quest could not be saved. Your delivered items were restored."
+            );
+        }
+    }
+
     void submit(Player player, String material, String quantityText) {
         final int quantity;
         try {

src/main/java/games/dmg/spigotquestboard/QuestCancellationController.java

@@ -0,0 +1,31 @@
+package games.dmg.spigotquestboard;
+
+import java.io.IOException;
+import java.time.Instant;
+import java.util.Objects;
+import java.util.UUID;
+import org.bukkit.entity.Player;
+
+final class QuestCancellationController implements QuestCancellationGateway {
+    private final QuestService quests;
+
+    QuestCancellationController(QuestService quests) {
+        this.quests = Objects.requireNonNull(quests, "quests");
+    }
+
+    @Override
+    public QuestClaim cancel(Player player, String questId, Instant cancelledAt) throws IOException {
+        Objects.requireNonNull(player, "player");
+        final UUID id;
+        try {
+            id = UUID.fromString(Objects.requireNonNull(questId, "questId"));
+        } catch (IllegalArgumentException exception) {
+            throw new IllegalArgumentException("Quest identifier must be a valid UUID.", exception);
+        }
+        QuestClaim claim = quests.cancel(id, player.getUniqueId(), cancelledAt);
+        player.sendMessage(
+            "Quest " + id + " cancelled. Your exact escrowed reward is ready to claim at a quest board."
+        );
+        return claim;
+    }
+}

src/main/java/games/dmg/spigotquestboard/QuestCancellationGateway.java

@@ -0,0 +1,9 @@
+package games.dmg.spigotquestboard;
+
+import java.io.IOException;
+import java.time.Instant;
+import org.bukkit.entity.Player;
+
+interface QuestCancellationGateway {
+    QuestClaim cancel(Player player, String questId, Instant cancelledAt) throws IOException;
+}

src/main/java/games/dmg/spigotquestboard/QuestClaim.java

@@ -0,0 +1,38 @@
+package games.dmg.spigotquestboard;
+
+import java.time.Instant;
+import java.util.List;
+import java.util.Objects;
+import java.util.UUID;
+
+record QuestClaim(
+    UUID id,
+    UUID questId,
+    UUID ownerId,
+    List<EscrowItem> items,
+    Instant createdAt,
+    QuestClaimSource source
+) {
+    QuestClaim {
+        Objects.requireNonNull(id, "id");
+        Objects.requireNonNull(questId, "questId");
+        Objects.requireNonNull(ownerId, "ownerId");
+        items = List.copyOf(Objects.requireNonNull(items, "items"));
+        if (items.isEmpty()) {
+            throw new IllegalArgumentException("Claim items must not be empty");
+        }
+        Objects.requireNonNull(createdAt, "createdAt");
+        Objects.requireNonNull(source, "source");
+    }
+
+    QuestClaim(
+        UUID id, UUID questId, UUID ownerId, List<EscrowItem> items, Instant createdAt
+    ) {
+        this(id, questId, ownerId, items, createdAt, QuestClaimSource.COMPLETION);
+    }
+
+    QuestClaimType type() {
+        return source == QuestClaimSource.COMPLETION
+            ? QuestClaimType.DELIVERED_BLOCKS : QuestClaimType.RETURNED_REWARD;
+    }
+}

src/main/java/games/dmg/spigotquestboard/QuestClaimController.java

@@ -0,0 +1,64 @@
+package games.dmg.spigotquestboard;
+
+import java.io.IOException;
+import java.util.List;
+import java.util.Objects;
+import org.bukkit.entity.Player;
+
+final class QuestClaimController implements QuestClaimGateway {
+    private final QuestService quests;
+    private final QuestClaimInventory inventory;
+
+    QuestClaimController(QuestService quests, QuestClaimInventory inventory) {
+        this.quests = Objects.requireNonNull(quests, "quests");
+        this.inventory = Objects.requireNonNull(inventory, "inventory");
+    }
+
+    @Override
+    public List<QuestClaim> pendingClaims(Player player) {
+        Objects.requireNonNull(player, "player");
+        return quests.claimsFor(player.getUniqueId());
+    }
+
+    @Override
+    public synchronized ClaimCollectionResult collect(Player player) throws IOException {
+        Objects.requireNonNull(player, "player");
+        List<QuestClaim> claims = quests.claimsFor(player.getUniqueId());
+        if (claims.isEmpty()) {
+            player.sendMessage("You have no pending quest claims.");
+            return new ClaimCollectionResult(0, 0);
+        }
+
+        int collected = 0;
+        int overflow = 0;
+        for (QuestClaim claim : claims) {
+            QuestClaimInventory.PreparedClaim prepared = inventory.prepare(claim.items());
+            QuestClaimInventory.Delivery delivery = prepared.deliver(player);
+            try {
+                quests.acknowledgeClaim(player.getUniqueId(), claim.id());
+            } catch (IOException | RuntimeException exception) {
+                delivery.rollback();
+                throw exception;
+            }
+            collected++;
+            overflow += delivery.overflowAmount();
+            player.sendMessage(description(claim));
+        }
+        player.sendMessage("Collected " + collected + " quest claim(s).");
+        if (overflow > 0) {
+            player.sendMessage(
+                overflow + " item(s) did not fit and were dropped at your feet, protected for you."
+            );
+        }
+        return new ClaimCollectionResult(collected, overflow);
+    }
+
+    private static String description(QuestClaim claim) {
+        if (claim.type() == QuestClaimType.DELIVERED_BLOCKS) {
+            return "Collected delivered items from completed quest " + claim.questId() + ".";
+        }
+        String reason = claim.source() == QuestClaimSource.EXPIRATION
+            ? "expired" : "cancelled";
+        return "Collected returned reward from " + reason + " quest " + claim.questId() + ".";
+    }
+}

src/main/java/games/dmg/spigotquestboard/QuestClaimGateway.java

@@ -0,0 +1,13 @@
+package games.dmg.spigotquestboard;
+
+import java.io.IOException;
+import java.util.List;
+import org.bukkit.entity.Player;
+
+interface QuestClaimGateway {
+    ClaimCollectionResult collect(Player player) throws IOException;
+
+    default List<QuestClaim> pendingClaims(Player player) {
+        return List.of();
+    }
+}

src/main/java/games/dmg/spigotquestboard/QuestClaimInventory.java

@@ -0,0 +1,17 @@
+package games.dmg.spigotquestboard;
+
+import java.util.List;
+import org.bukkit.entity.Player;
+
+interface QuestClaimInventory {
+    PreparedClaim prepare(List<EscrowItem> items);
+
+    interface PreparedClaim {
+        Delivery deliver(Player player);
+    }
+
+    interface Delivery {
+        int overflowAmount();
+        void rollback();
+    }
+}

src/main/java/games/dmg/spigotquestboard/QuestClaimSource.java

@@ -0,0 +1,7 @@
+package games.dmg.spigotquestboard;
+
+enum QuestClaimSource {
+    COMPLETION,
+    CANCELLATION,
+    EXPIRATION
+}

src/main/java/games/dmg/spigotquestboard/QuestClaimType.java

@@ -0,0 +1,6 @@
+package games.dmg.spigotquestboard;
+
+enum QuestClaimType {
+    DELIVERED_BLOCKS,
+    RETURNED_REWARD
+}

src/main/java/games/dmg/spigotquestboard/QuestCommand.java

@@ -14,26 +14,165 @@ import org.bukkit.entity.Player;
 
 final class QuestCommand implements CommandExecutor, TabCompleter {
     private static final List<String> QUANTITIES = List.of("1", "16", "32", "64");
+    private static final double COMMAND_CREATION_DISTANCE = 5.0;
     private final QuestCreationGateway creator;
     private final QuestBrowser browser;
+    private final QuestCompletionGateway completer;
+    private final QuestCancellationGateway canceller;
+    private final QuestClaimGateway claimant;
     private final Clock clock;
+    private final PlayerCommandSettings playerCommands;
+    private final BoardProximity boardProximity;
 
     QuestCommand(QuestCreationGateway creator, QuestBrowser browser, Clock clock) {
+        this(creator, browser, null, null, null, clock);
+    }
+
+    QuestCommand(
+        QuestCreationGateway creator,
+        QuestBrowser browser,
+        QuestCompletionGateway completer,
+        Clock clock
+    ) {
+        this(creator, browser, completer, null, null, clock);
+    }
+
+    QuestCommand(
+        QuestCreationGateway creator,
+        QuestBrowser browser,
+        QuestCompletionGateway completer,
+        QuestCancellationGateway canceller,
+        Clock clock
+    ) {
+        this(creator, browser, completer, canceller, null, clock);
+    }
+
+    QuestCommand(
+        QuestCreationGateway creator,
+        QuestBrowser browser,
+        QuestCompletionGateway completer,
+        QuestCancellationGateway canceller,
+        QuestClaimGateway claimant,
+        Clock clock
+    ) {
+        this(creator, browser, completer, canceller, claimant, clock, null, null);
+    }
+
+    QuestCommand(
+        QuestCreationGateway creator,
+        QuestBrowser browser,
+        QuestCompletionGateway completer,
+        QuestCancellationGateway canceller,
+        QuestClaimGateway claimant,
+        Clock clock,
+        PlayerCommandSettings playerCommands
+    ) {
+        this(creator, browser, completer, canceller, claimant, clock, playerCommands, null);
+    }
+
+    QuestCommand(
+        QuestCreationGateway creator,
+        QuestBrowser browser,
+        QuestCompletionGateway completer,
+        QuestCancellationGateway canceller,
+        QuestClaimGateway claimant,
+        Clock clock,
+        PlayerCommandSettings playerCommands,
+        BoardProximity boardProximity
+    ) {
         this.creator = Objects.requireNonNull(creator, "creator");
         this.browser = Objects.requireNonNull(browser, "browser");
+        this.completer = completer;
+        this.canceller = canceller;
+        this.claimant = claimant;
         this.clock = Objects.requireNonNull(clock, "clock");
+        this.playerCommands = playerCommands;
+        this.boardProximity = boardProximity;
     }
 
     @Override
     public boolean onCommand(
         CommandSender sender, Command command, String label, String[] arguments
     ) {
+        if (!playerCommandsEnabled()) {
+            if (isCreate(arguments) && sender instanceof Player player) {
+                if (!isNearBoard(player)) {
+                    sender.sendMessage(
+                        "Move closer to a quest board to create a quest by command."
+                    );
+                    return true;
+                }
+            } else {
+                sender.sendMessage(
+                    "Player quest commands are disabled. Use a physical quest board instead."
+                );
+                return true;
+            }
+        }
         if (arguments.length == 0
             || (arguments.length == 1 && "list".equalsIgnoreCase(arguments[0]))) {
             Instant now = clock.instant();
             sender.sendMessage(QuestListingFormatter.formatAll(browser.activeQuests(now), now));
             return true;
         }
+        if (arguments.length == 1 && "claim".equalsIgnoreCase(arguments[0])) {
+            if (!(sender instanceof Player player)) {
+                sender.sendMessage("Only players can collect quest claims.");
+                return true;
+            }
+            if (claimant == null) {
+                sender.sendMessage("Quest claims are unavailable.");
+                return true;
+            }
+            try {
+                claimant.collect(player);
+            } catch (IOException | RuntimeException exception) {
+                sender.sendMessage(
+                    "Your claim could not be collected safely. It remains pending; please try again."
+                );
+            }
+            return true;
+        }
+        if (arguments.length == 2 && "complete".equalsIgnoreCase(arguments[0])) {
+            if (!(sender instanceof Player player)) {
+                sender.sendMessage("Only players can complete quests with inventory items.");
+                return true;
+            }
+            if (completer == null) {
+                sender.sendMessage("Quest completion is unavailable.");
+                return true;
+            }
+            try {
+                completer.complete(player, arguments[1], clock.instant());
+            } catch (IllegalArgumentException | IllegalStateException exception) {
+                sender.sendMessage(exception.getMessage());
+            } catch (IOException exception) {
+                sender.sendMessage(
+                    "The quest could not be saved. Your delivered items were restored."
+                );
+            }
+            return true;
+        }
+        if (arguments.length == 2 && "cancel".equalsIgnoreCase(arguments[0])) {
+            if (!(sender instanceof Player player)) {
+                sender.sendMessage("Only players can cancel quests.");
+                return true;
+            }
+            if (canceller == null) {
+                sender.sendMessage("Quest cancellation is unavailable.");
+                return true;
+            }
+            try {
+                canceller.cancel(player, arguments[1], clock.instant());
+            } catch (IllegalArgumentException | IllegalStateException exception) {
+                sender.sendMessage(exception.getMessage());
+            } catch (IOException exception) {
+                sender.sendMessage(
+                    "The quest could not be saved. It remains active and its reward remains escrowed."
+                );
+            }
+            return true;
+        }
         if (arguments.length != 3 || !"create".equalsIgnoreCase(arguments[0])) {
             usage(sender);
             return true;
@@ -64,14 +203,27 @@ final class QuestCommand implements CommandExecutor, TabCompleter {
     public List<String> onTabComplete(
         CommandSender sender, Command command, String alias, String[] arguments
     ) {
-        if (!(sender instanceof Player)) {
+        if (!(sender instanceof Player player)) {
             return List.of();
         }
+        if (!playerCommandsEnabled()) {
+            if (!isNearBoard(player)) {
+                return List.of();
+            }
+            if (arguments.length == 1) {
+                return startsWith(List.of("create"), arguments[0]);
+            }
+            if (!isCreate(arguments)) {
+                return List.of();
+            }
+        }
         if (arguments.length == 1) {
-            return startsWith(List.of("create", "list"), arguments[0]);
+            return startsWith(
+                List.of("create", "list", "complete", "cancel", "claim"), arguments[0]
+            );
         }
         if (arguments.length == 2 && "create".equalsIgnoreCase(arguments[0])) {
-            return creator.suggestBlockMaterials(arguments[1]);
+            return creator.suggestItemMaterials(arguments[1]);
         }
         if (arguments.length == 3 && "create".equalsIgnoreCase(arguments[0])) {
             return startsWith(QUANTITIES, arguments[2]);
@@ -80,7 +232,6 @@ final class QuestCommand implements CommandExecutor, TabCompleter {
             return startsWith(browser.completableQuestIds(clock.instant()), arguments[1]);
         }
         if (arguments.length == 2 && "cancel".equalsIgnoreCase(arguments[0])) {
-            Player player = (Player) sender;
             return startsWith(
                 browser.cancellableQuestIds(player.getUniqueId(), clock.instant()), arguments[1]
             );
@@ -88,6 +239,25 @@ final class QuestCommand implements CommandExecutor, TabCompleter {
         return List.of();
     }
 
+    private boolean playerCommandsEnabled() {
+        return playerCommands == null || playerCommands.enabled();
+    }
+
+    private boolean isNearBoard(Player player) {
+        if (boardProximity == null) {
+            return false;
+        }
+        org.bukkit.Location location = player.getLocation();
+        return boardProximity.isWithin(
+            player.getWorld().getUID(), location.getX(), location.getY(), location.getZ(),
+            COMMAND_CREATION_DISTANCE
+        );
+    }
+
+    private static boolean isCreate(String[] arguments) {
+        return arguments.length > 0 && "create".equalsIgnoreCase(arguments[0]);
+    }
+
     private static List<String> startsWith(List<String> candidates, String prefix) {
         String normalized = prefix.toLowerCase(Locale.ROOT);
         return candidates.stream()
@@ -96,7 +266,10 @@ final class QuestCommand implements CommandExecutor, TabCompleter {
     }
 
     private static void usage(CommandSender sender) {
-        sender.sendMessage("Usage: /quests [list] | /quests create <block> <quantity>");
+        sender.sendMessage(
+            "Usage: /quests [list] | /quests create <item> <quantity> | "
+                + "/quests complete <quest> | /quests cancel <quest> | /quests claim"
+        );
         sender.sendMessage("Hold the entire reward stack in your main hand; its exact metadata will be escrowed.");
     }
 }

src/main/java/games/dmg/spigotquestboard/QuestCompletion.java

@@ -0,0 +1,9 @@
+package games.dmg.spigotquestboard;
+
+import java.util.List;
+
+record QuestCompletion(Quest quest, QuestClaim claim, List<EscrowItem> reward) {
+    QuestCompletion {
+        reward = List.copyOf(reward);
+    }
+}

src/main/java/games/dmg/spigotquestboard/QuestCompletionController.java

@@ -0,0 +1,57 @@
+package games.dmg.spigotquestboard;
+
+import java.io.IOException;
+import java.time.Instant;
+import java.util.Objects;
+import java.util.UUID;
+import org.bukkit.entity.Player;
+
+final class QuestCompletionController implements QuestCompletionGateway {
+    private final QuestService quests;
+    private final QuestCompletionInventory inventory;
+    private final IssuerNotifier notifier;
+
+    QuestCompletionController(
+        QuestService quests, QuestCompletionInventory inventory, IssuerNotifier notifier
+    ) {
+        this.quests = Objects.requireNonNull(quests, "quests");
+        this.inventory = Objects.requireNonNull(inventory, "inventory");
+        this.notifier = Objects.requireNonNull(notifier, "notifier");
+    }
+
+    @Override
+    public QuestCompletion complete(Player player, String questId, Instant completedAt)
+        throws IOException {
+        Objects.requireNonNull(player, "player");
+        final UUID id;
+        try {
+            id = UUID.fromString(Objects.requireNonNull(questId, "questId"));
+        } catch (IllegalArgumentException exception) {
+            throw new IllegalArgumentException("Quest identifier must be a valid UUID.", exception);
+        }
+        Quest quest = quests.completionCandidate(id, completedAt);
+        QuestCompletionInventory.PreparedReward reward = inventory.prepare(quest.reward());
+        QuestCompletionInventory.RemovedDelivery delivery = inventory.remove(
+            player, quest.requestedMaterial(), quest.requestedAmount()
+        );
+        final QuestCompletion completion;
+        try {
+            completion = quests.complete(id, delivery.items(), completedAt);
+        } catch (IOException | RuntimeException exception) {
+            delivery.rollback();
+            throw exception;
+        }
+
+        int overflow = reward.grantAndDropOverflow(player);
+        player.sendMessage(
+            "Quest " + id + " completed. You received the exact escrowed reward."
+        );
+        if (overflow > 0) {
+            player.sendMessage(
+                overflow + " reward item(s) did not fit and were dropped safely at your feet."
+            );
+        }
+        notifier.notifyIfOnline(completion.quest().issuerId());
+        return completion;
+    }
+}

src/main/java/games/dmg/spigotquestboard/QuestCompletionGateway.java

@@ -0,0 +1,9 @@
+package games.dmg.spigotquestboard;
+
+import java.io.IOException;
+import java.time.Instant;
+import org.bukkit.entity.Player;
+
+interface QuestCompletionGateway {
+    QuestCompletion complete(Player player, String questId, Instant completedAt) throws IOException;
+}

src/main/java/games/dmg/spigotquestboard/QuestCompletionInventory.java

@@ -0,0 +1,19 @@
+package games.dmg.spigotquestboard;
+
+import java.util.List;
+import org.bukkit.entity.Player;
+
+interface QuestCompletionInventory {
+    RemovedDelivery remove(Player player, String material, int amount);
+
+    PreparedReward prepare(List<EscrowItem> reward);
+
+    interface RemovedDelivery {
+        List<EscrowItem> items();
+        void rollback();
+    }
+
+    interface PreparedReward {
+        int grantAndDropOverflow(Player player);
+    }
+}

src/main/java/games/dmg/spigotquestboard/QuestCreationController.java

@@ -8,12 +8,12 @@ import org.bukkit.entity.Player;
 
 final class QuestCreationController implements QuestCreationGateway {
     private final QuestService quests;
-    private final BlockMaterialCatalog materials;
+    private final ItemMaterialCatalog materials;
     private final HeldRewardInventory rewards;
 
     QuestCreationController(
         QuestService quests,
-        BlockMaterialCatalog materials,
+        ItemMaterialCatalog materials,
         HeldRewardInventory rewards
     ) {
         this.quests = Objects.requireNonNull(quests, "quests");
@@ -29,9 +29,9 @@ final class QuestCreationController implements QuestCreationGateway {
         if (requestedAmount <= 0) {
             throw new IllegalArgumentException("Requested quantity must be positive");
         }
-        String material = materials.normalizeBlock(requestedMaterial)
+        String material = materials.normalizeItem(requestedMaterial)
             .orElseThrow(() -> new IllegalArgumentException(
-                "Requested material must be a valid block"
+                "Requested material must be a valid item"
             ));
         HeldRewardInventory.RemovedReward removed = rewards.remove(player);
         try {
@@ -46,7 +46,7 @@ final class QuestCreationController implements QuestCreationGateway {
     }
 
     @Override
-    public List<String> suggestBlockMaterials(String prefix) {
+    public List<String> suggestItemMaterials(String prefix) {
         return materials.suggest(prefix == null ? "" : prefix);
     }
 }

src/main/java/games/dmg/spigotquestboard/QuestCreationGateway.java

@@ -9,5 +9,5 @@ interface QuestCreationGateway {
     Quest create(Player player, String requestedMaterial, int requestedAmount, Instant createdAt)
         throws IOException;
 
-    List<String> suggestBlockMaterials(String prefix);
+    List<String> suggestItemMaterials(String prefix);
 }

src/main/java/games/dmg/spigotquestboard/QuestExpiryTask.java

@@ -0,0 +1,39 @@
+package games.dmg.spigotquestboard;
+
+import java.io.IOException;
+import java.time.Clock;
+import java.util.LinkedHashSet;
+import java.util.List;
+import java.util.Set;
+import java.util.logging.Level;
+import java.util.logging.Logger;
+
+final class QuestExpiryTask implements Runnable {
+    private final QuestService quests;
+    private final IssuerNotifier notifier;
+    private final Clock clock;
+    private final Logger logger;
+
+    QuestExpiryTask(
+        QuestService quests, IssuerNotifier notifier, Clock clock, Logger logger
+    ) {
+        this.quests = quests;
+        this.notifier = notifier;
+        this.clock = clock;
+        this.logger = logger;
+    }
+
+    @Override
+    public void run() {
+        final List<QuestClaim> claims;
+        try {
+            claims = quests.expire(clock.instant());
+        } catch (IOException exception) {
+            logger.log(Level.WARNING, "Could not persist expired quests; expiration will be retried", exception);
+            return;
+        }
+        Set<java.util.UUID> owners = new LinkedHashSet<>();
+        claims.forEach(claim -> owners.add(claim.ownerId()));
+        owners.forEach(notifier::notifyIfOnline);
+    }
+}

src/main/java/games/dmg/spigotquestboard/QuestListingFormatter.java

@@ -37,6 +37,9 @@ final class QuestListingFormatter {
     }
 
     private static String formatReward(EscrowItem item) {
+        if (item.customName() != null) {
+            return item.amount() + " × " + item.customName() + " (" + item.material() + ")";
+        }
         return item.amount() + " × " + item.material()
             + (item.serializedItem() == null ? "" : " (with exact item data)");
     }

src/main/java/games/dmg/spigotquestboard/QuestService.java

@@ -3,20 +3,21 @@ package games.dmg.spigotquestboard;
 import java.io.IOException;
 import java.time.Instant;
 import java.time.temporal.ChronoUnit;
+import java.util.ArrayList;
 import java.util.LinkedHashMap;
 import java.util.List;
-import java.util.Map;
 import java.util.Locale;
+import java.util.Map;
 import java.util.Objects;
 import java.util.UUID;
 
 final class QuestService implements QuestBrowser {
     private final QuestRepository repository;
-    private Map<UUID, Quest> quests;
+    private QuestState state;
 
     QuestService(QuestRepository repository) throws IOException {
         this.repository = Objects.requireNonNull(repository, "repository");
-        quests = new LinkedHashMap<>(repository.load().quests());
+        state = repository.load();
     }
 
     synchronized Quest create(
@@ -32,29 +33,217 @@ final class QuestService implements QuestBrowser {
         String material = Objects.requireNonNull(requestedMaterial, "requestedMaterial")
             .trim().toUpperCase(Locale.ROOT);
         if (material.isEmpty() || "AIR".equals(material)) {
-            throw new IllegalArgumentException("Requested material must be a block");
+            throw new IllegalArgumentException("Requested material must be a valid item");
         }
         Quest quest = new Quest(
             UUID.randomUUID(), issuerId, issuerName, material, requestedAmount,
             reward, createdAt, createdAt.plus(7, ChronoUnit.DAYS)
         );
-        Map<UUID, Quest> candidate = new LinkedHashMap<>(quests);
-        candidate.put(quest.id(), quest);
-        repository.save(new QuestState(candidate));
-        quests = Map.copyOf(candidate);
+        Map<UUID, Quest> quests = new LinkedHashMap<>(state.quests());
+        quests.put(quest.id(), quest);
+        save(new QuestState(quests, state.claims(), state.notifications()));
         return quest;
     }
 
+    synchronized Quest completionCandidate(UUID questId, Instant now) {
+        Objects.requireNonNull(questId, "questId");
+        Objects.requireNonNull(now, "now");
+        Quest quest = state.quests().get(questId);
+        if (quest == null) {
+            throw new IllegalArgumentException("Quest not found: " + questId);
+        }
+        if (quest.status() != QuestStatus.ACTIVE || !now.isBefore(quest.expiresAt())) {
+            throw new IllegalStateException("That quest is no longer active or has expired.");
+        }
+        return quest;
+    }
+
+    synchronized QuestCompletion complete(
+        UUID questId, EscrowItem delivered, Instant completedAt
+    ) throws IOException {
+        return complete(questId, List.of(delivered), completedAt);
+    }
+
+    synchronized QuestCompletion complete(
+        UUID questId, List<EscrowItem> delivered, Instant completedAt
+    ) throws IOException {
+        Quest active = completionCandidate(questId, completedAt);
+        List<EscrowItem> delivery = List.copyOf(Objects.requireNonNull(delivered, "delivered"));
+        if (delivery.isEmpty()
+            || delivery.stream().anyMatch(item -> !item.material().equals(active.requestedMaterial()))
+            || delivery.stream().mapToInt(EscrowItem::amount).sum() != active.requestedAmount()) {
+            throw new IllegalArgumentException(
+                "Delivery must contain exactly " + active.requestedAmount() + " "
+                    + active.requestedMaterial() + "."
+            );
+        }
+
+        Quest completed = new Quest(
+            active.id(), active.issuerId(), active.issuerName(), active.requestedMaterial(),
+            active.requestedAmount(), active.reward(), active.createdAt(), active.expiresAt(),
+            QuestStatus.COMPLETED
+        );
+        QuestClaim claim = new QuestClaim(
+            UUID.randomUUID(), active.id(), active.issuerId(), delivery, completedAt,
+            QuestClaimSource.COMPLETION
+        );
+        IssuerNotification notification = new IssuerNotification(
+            UUID.randomUUID(), active.id(), active.issuerId(),
+            "Quest " + active.id() + " was completed. Your delivered "
+                + active.requestedMaterial() + " items can be claimed at a quest board.",
+            completedAt
+        );
+
+        Map<UUID, Quest> quests = new LinkedHashMap<>(state.quests());
+        quests.put(active.id(), completed);
+        Map<UUID, List<QuestClaim>> claims = new LinkedHashMap<>(state.claims());
+        List<QuestClaim> ownerClaims = new ArrayList<>(
+            claims.getOrDefault(active.issuerId(), List.of())
+        );
+        ownerClaims.add(claim);
+        claims.put(active.issuerId(), ownerClaims);
+        Map<UUID, IssuerNotification> notifications = new LinkedHashMap<>(state.notifications());
+        notifications.put(notification.id(), notification);
+        save(new QuestState(quests, claims, notifications));
+        return new QuestCompletion(completed, claim, completed.reward());
+    }
+
+    synchronized QuestClaim cancel(UUID questId, UUID issuerId, Instant cancelledAt)
+        throws IOException {
+        Objects.requireNonNull(questId, "questId");
+        Objects.requireNonNull(issuerId, "issuerId");
+        Objects.requireNonNull(cancelledAt, "cancelledAt");
+        Quest active = state.quests().get(questId);
+        if (active == null) {
+            throw new IllegalArgumentException("Quest not found: " + questId);
+        }
+        if (!active.issuerId().equals(issuerId)) {
+            throw new IllegalArgumentException("Only the quest issuer can cancel this quest.");
+        }
+        if (active.status() != QuestStatus.ACTIVE || !cancelledAt.isBefore(active.expiresAt())) {
+            throw new IllegalStateException("That quest is no longer active or has expired.");
+        }
+
+        Quest cancelled = new Quest(
+            active.id(), active.issuerId(), active.issuerName(), active.requestedMaterial(),
+            active.requestedAmount(), active.reward(), active.createdAt(), active.expiresAt(),
+            QuestStatus.CANCELLED
+        );
+        QuestClaim claim = new QuestClaim(
+            UUID.randomUUID(), active.id(), active.issuerId(), active.reward(), cancelledAt,
+            QuestClaimSource.CANCELLATION
+        );
+        Map<UUID, Quest> quests = new LinkedHashMap<>(state.quests());
+        quests.put(active.id(), cancelled);
+        Map<UUID, List<QuestClaim>> claims = new LinkedHashMap<>(state.claims());
+        List<QuestClaim> ownerClaims = new ArrayList<>(
+            claims.getOrDefault(active.issuerId(), List.of())
+        );
+        ownerClaims.add(claim);
+        claims.put(active.issuerId(), ownerClaims);
+        save(new QuestState(quests, claims, state.notifications()));
+        return claim;
+    }
+
+    synchronized List<QuestClaim> expire(Instant now) throws IOException {
+        Objects.requireNonNull(now, "now");
+        Map<UUID, Quest> quests = new LinkedHashMap<>(state.quests());
+        Map<UUID, List<QuestClaim>> claims = mutableClaims(state.claims());
+        Map<UUID, IssuerNotification> notifications = new LinkedHashMap<>(state.notifications());
+        List<QuestClaim> expiredClaims = new ArrayList<>();
+
+        for (Quest active : state.quests().values()) {
+            if (active.status() != QuestStatus.ACTIVE || active.expiresAt().isAfter(now)) {
+                continue;
+            }
+            Quest expired = new Quest(
+                active.id(), active.issuerId(), active.issuerName(), active.requestedMaterial(),
+                active.requestedAmount(), active.reward(), active.createdAt(), active.expiresAt(),
+                QuestStatus.EXPIRED
+            );
+            QuestClaim claim = new QuestClaim(
+                UUID.randomUUID(), active.id(), active.issuerId(), active.reward(), active.expiresAt(),
+                QuestClaimSource.EXPIRATION
+            );
+            IssuerNotification notification = new IssuerNotification(
+                UUID.randomUUID(), active.id(), active.issuerId(),
+                "Quest " + active.id() + " expired. Your returned reward can be claimed "
+                    + "at any quest board or with /quests claim.",
+                active.expiresAt()
+            );
+            quests.put(active.id(), expired);
+            claims.computeIfAbsent(active.issuerId(), ignored -> new ArrayList<>()).add(claim);
+            notifications.put(notification.id(), notification);
+            expiredClaims.add(claim);
+        }
+        if (!expiredClaims.isEmpty()) {
+            save(new QuestState(quests, claims, notifications));
+        }
+        return List.copyOf(expiredClaims);
+    }
+
+    synchronized List<QuestClaim> claimsFor(UUID ownerId) {
+        Objects.requireNonNull(ownerId, "ownerId");
+        return state.claims().getOrDefault(ownerId, List.of());
+    }
+
+    synchronized void acknowledgeClaim(UUID ownerId, UUID claimId) throws IOException {
+        Objects.requireNonNull(ownerId, "ownerId");
+        Objects.requireNonNull(claimId, "claimId");
+        List<QuestClaim> existing = state.claims().getOrDefault(ownerId, List.of());
+        if (existing.stream().noneMatch(claim -> claim.id().equals(claimId))) {
+            return;
+        }
+        Map<UUID, List<QuestClaim>> claims = mutableClaims(state.claims());
+        List<QuestClaim> remaining = new ArrayList<>(claims.get(ownerId));
+        remaining.removeIf(claim -> claim.id().equals(claimId));
+        if (remaining.isEmpty()) {
+            claims.remove(ownerId);
+        } else {
+            claims.put(ownerId, remaining);
+        }
+        save(new QuestState(state.quests(), claims, state.notifications()));
+    }
+
+    synchronized List<IssuerNotification> pendingNotifications(UUID recipientId) {
+        Objects.requireNonNull(recipientId, "recipientId");
+        return state.notifications().values().stream()
+            .filter(notification -> notification.recipientId().equals(recipientId))
+            .toList();
+    }
+
+    synchronized void markNotificationDelivered(UUID notificationId) throws IOException {
+        if (!state.notifications().containsKey(notificationId)) {
+            return;
+        }
+        Map<UUID, IssuerNotification> notifications = new LinkedHashMap<>(state.notifications());
+        notifications.remove(notificationId);
+        save(new QuestState(state.quests(), state.claims(), notifications));
+    }
+
     @Override
     public synchronized List<Quest> activeQuests(Instant now) {
         Objects.requireNonNull(now, "now");
-        return quests.values().stream()
+        return state.quests().values().stream()
             .filter(quest -> quest.status() == QuestStatus.ACTIVE)
             .filter(quest -> now.isBefore(quest.expiresAt()))
             .toList();
     }
 
     synchronized QuestState state() {
-        return new QuestState(quests);
+        return state;
+    }
+
+    private static Map<UUID, List<QuestClaim>> mutableClaims(
+        Map<UUID, List<QuestClaim>> source
+    ) {
+        Map<UUID, List<QuestClaim>> copy = new LinkedHashMap<>();
+        source.forEach((owner, claims) -> copy.put(owner, new ArrayList<>(claims)));
+        return copy;
+    }
+
+    private void save(QuestState candidate) throws IOException {
+        repository.save(candidate);
+        state = candidate;
     }
 }

src/main/java/games/dmg/spigotquestboard/QuestState.java

@@ -1,10 +1,16 @@
 package games.dmg.spigotquestboard;
 
+import java.util.LinkedHashMap;
+import java.util.List;
 import java.util.Map;
 import java.util.Objects;
 import java.util.UUID;
 
-record QuestState(Map<UUID, Quest> quests) {
+record QuestState(
+    Map<UUID, Quest> quests,
+    Map<UUID, List<QuestClaim>> claims,
+    Map<UUID, IssuerNotification> notifications
+) {
     QuestState {
         quests = Map.copyOf(Objects.requireNonNull(quests, "quests"));
         for (Map.Entry<UUID, Quest> entry : quests.entrySet()) {
@@ -12,9 +18,29 @@ record QuestState(Map<UUID, Quest> quests) {
                 throw new IllegalArgumentException("Quest map key does not match quest id");
             }
         }
+        Map<UUID, List<QuestClaim>> immutableClaims = new LinkedHashMap<>();
+        for (Map.Entry<UUID, List<QuestClaim>> entry
+            : Objects.requireNonNull(claims, "claims").entrySet()) {
+            List<QuestClaim> ownerClaims = List.copyOf(entry.getValue());
+            if (ownerClaims.stream().anyMatch(claim -> !claim.ownerId().equals(entry.getKey()))) {
+                throw new IllegalArgumentException("Claim map key does not match owner id");
+            }
+            immutableClaims.put(entry.getKey(), ownerClaims);
+        }
+        claims = Map.copyOf(immutableClaims);
+        notifications = Map.copyOf(Objects.requireNonNull(notifications, "notifications"));
+        for (Map.Entry<UUID, IssuerNotification> entry : notifications.entrySet()) {
+            if (!entry.getKey().equals(entry.getValue().id())) {
+                throw new IllegalArgumentException("Notification map key does not match id");
+            }
+        }
+    }
+
+    QuestState(Map<UUID, Quest> quests) {
+        this(quests, Map.of(), Map.of());
     }
 
     static QuestState empty() {
-        return new QuestState(Map.of());
+        return new QuestState(Map.of(), Map.of(), Map.of());
     }
 }

src/main/java/games/dmg/spigotquestboard/SpigotQuestBoardPlugin.java

@@ -12,40 +12,100 @@ public final class SpigotQuestBoardPlugin extends JavaPlugin {
     public void onEnable() {
         final BoardRegistry boards;
         final QuestService quests;
+        final PlayerCommandSettings playerCommands;
+        final int upgradedBoards;
         try {
             boards = new BoardRegistry(new YamlBoardRepository(
                 getDataFolder().toPath().resolve("boards.yml")
             ));
+            upgradedBoards = upgradePhysicalBoards(boards, worldId -> {
+                org.bukkit.World world = getServer().getWorld(worldId);
+                return world == null ? null : new BukkitPhysicalBoardWorld(world);
+            });
             quests = new QuestService(new YamlQuestRepository(
                 getDataFolder().toPath().resolve("quests.yml")
             ));
+            playerCommands = new PlayerCommandSettings(
+                new YamlPlayerCommandSettingsRepository(
+                    getDataFolder().toPath().resolve("settings.yml")
+                )
+            );
         } catch (IOException exception) {
-            getLogger().log(Level.SEVERE, "Could not load quest board state", exception);
+            getLogger().log(Level.SEVERE, "Could not load plugin state", exception);
             getServer().getPluginManager().disablePlugin(this);
             return;
         }
 
-        QuestAdminCommand admin = new QuestAdminCommand(boards);
-        command("questadmin").setExecutor(admin);
-
         QuestCreationGateway creator = new QuestCreationController(
-            quests, new BukkitBlockMaterialCatalog(), new BukkitHeldRewardInventory()
+            quests, new BukkitItemMaterialCatalog(), new BukkitHeldRewardInventory()
         );
-        QuestCommand questCommand = new QuestCommand(creator, quests, Clock.systemUTC());
-        command("quests").setExecutor(questCommand);
-        command("quests").setTabCompleter(questCommand);
+        Clock clock = Clock.systemUTC();
+        BukkitIssuerNotifier notifier = new BukkitIssuerNotifier(
+            quests, getServer(), getLogger(), clock
+        );
+        QuestCompletionGateway completer = new QuestCompletionController(
+            quests, new BukkitQuestCompletionInventory(), notifier
+        );
+        QuestCancellationGateway canceller = new QuestCancellationController(quests);
+        QuestClaimGateway claimant = new QuestClaimController(
+            quests, new BukkitQuestClaimInventory()
+        );
+        CommandHandlers handlers = commandHandlers(
+            boards, playerCommands, creator, quests, completer, canceller, claimant, clock
+        );
+        command("questadmin").setExecutor(handlers.admin());
+        command("questadmin").setTabCompleter(handlers.admin());
+        command("quests").setExecutor(handlers.quests());
+        command("quests").setTabCompleter(handlers.quests());
+        getServer().getPluginManager().registerEvents(notifier, this);
         getServer().getPluginManager().registerEvents(
             new QuestBoardInteractionListener(
-                boards, new QuestBoardDialogUi(creator, quests, Clock.systemUTC())
+                boards, new QuestBoardDialogUi(
+                    creator, quests, completer, canceller, claimant, clock
+                )
             ),
             this
         );
+        getServer().getScheduler().runTaskTimer(
+            this,
+            new QuestExpiryTask(quests, notifier, clock, getLogger()),
+            0L,
+            20L
+        );
         getLogger().info(
             "Spigot Quest Board enabled with " + boards.size() + " boards and "
-                + quests.state().quests().size() + " quests."
+                + quests.state().quests().size() + " quests; upgraded " + upgradedBoards
+                + " physical boards."
         );
     }
 
+    static int upgradePhysicalBoards(
+        BoardRegistry boards, PhysicalBoardUpgrader.WorldFactory worlds
+    ) throws IOException {
+        return new PhysicalBoardUpgrader(boards, worlds).upgrade();
+    }
+
+    static CommandHandlers commandHandlers(
+        BoardRegistry boards,
+        PlayerCommandSettings playerCommands,
+        QuestCreationGateway creator,
+        QuestBrowser browser,
+        QuestCompletionGateway completer,
+        QuestCancellationGateway canceller,
+        QuestClaimGateway claimant,
+        Clock clock
+    ) {
+        return new CommandHandlers(
+            new QuestAdminCommand(boards, playerCommands),
+            new QuestCommand(
+                creator, browser, completer, canceller, claimant, clock, playerCommands,
+                boards
+            )
+        );
+    }
+
+    record CommandHandlers(QuestAdminCommand admin, QuestCommand quests) { }
+
     private PluginCommand command(String name) {
         return Objects.requireNonNull(getCommand(name), "Missing command metadata for " + name);
     }

src/main/java/games/dmg/spigotquestboard/YamlPlayerCommandSettingsRepository.java

@@ -0,0 +1,53 @@
+package games.dmg.spigotquestboard;
+
+import java.io.IOException;
+import java.nio.file.AtomicMoveNotSupportedException;
+import java.nio.file.Files;
+import java.nio.file.Path;
+import java.nio.file.StandardCopyOption;
+import java.util.Objects;
+import org.bukkit.configuration.InvalidConfigurationException;
+import org.bukkit.configuration.file.YamlConfiguration;
+
+final class YamlPlayerCommandSettingsRepository implements PlayerCommandSettingsRepository {
+    private static final String ENABLED_PATH = "player-commands.enabled";
+    private final Path path;
+
+    YamlPlayerCommandSettingsRepository(Path path) {
+        this.path = Objects.requireNonNull(path, "path");
+    }
+
+    @Override
+    public boolean loadEnabled() throws IOException {
+        if (!Files.exists(path)) {
+            return false;
+        }
+        YamlConfiguration yaml = new YamlConfiguration();
+        try {
+            yaml.load(path.toFile());
+        } catch (InvalidConfigurationException exception) {
+            throw new IOException("Invalid player command settings", exception);
+        }
+        return yaml.getBoolean(ENABLED_PATH, false);
+    }
+
+    @Override
+    public void saveEnabled(boolean enabled) throws IOException {
+        YamlConfiguration yaml = new YamlConfiguration();
+        yaml.set(ENABLED_PATH, enabled);
+        Path parent = path.toAbsolutePath().getParent();
+        Files.createDirectories(parent);
+        Path temporary = Files.createTempFile(parent, path.getFileName().toString(), ".tmp");
+        try {
+            yaml.save(temporary.toFile());
+            try {
+                Files.move(temporary, path, StandardCopyOption.REPLACE_EXISTING,
+                    StandardCopyOption.ATOMIC_MOVE);
+            } catch (AtomicMoveNotSupportedException exception) {
+                Files.move(temporary, path, StandardCopyOption.REPLACE_EXISTING);
+            }
+        } finally {
+            Files.deleteIfExists(temporary);
+        }
+    }
+}

src/main/java/games/dmg/spigotquestboard/YamlQuestRepository.java

@@ -34,6 +34,8 @@ final class YamlQuestRepository implements QuestRepository {
             throw new IOException("Invalid quest state", exception);
         }
         Map<UUID, Quest> quests = new LinkedHashMap<>();
+        Map<UUID, List<QuestClaim>> claims = new LinkedHashMap<>();
+        Map<UUID, IssuerNotification> notifications = new LinkedHashMap<>();
         try {
             for (Map<?, ?> entry : yaml.getMapList("quests")) {
                 UUID id = UUID.fromString(requiredString(entry, "id"));
@@ -43,7 +45,7 @@ final class YamlQuestRepository implements QuestRepository {
                     requiredString(entry, "issuer-name"),
                     requiredString(entry, "requested-material"),
                     requiredInteger(entry, "requested-amount"),
-                    readRewards(entry.get("reward")),
+                    readItems(entry.get("reward"), "reward"),
                     Instant.parse(requiredString(entry, "created-at")),
                     Instant.parse(requiredString(entry, "expires-at")),
                     readStatus(entry.get("status"))
@@ -52,10 +54,37 @@ final class YamlQuestRepository implements QuestRepository {
                     throw new IllegalArgumentException("Duplicate quest id: " + id);
                 }
             }
+            for (Map<?, ?> entry : yaml.getMapList("claims")) {
+                QuestClaim claim = new QuestClaim(
+                    UUID.fromString(requiredString(entry, "id")),
+                    UUID.fromString(requiredString(entry, "quest-id")),
+                    UUID.fromString(requiredString(entry, "owner-id")),
+                    readItems(entry.get("items"), "claim items"),
+                    Instant.parse(requiredString(entry, "created-at")),
+                    readClaimSource(entry.get("source"), quests.get(
+                        UUID.fromString(requiredString(entry, "quest-id"))
+                    ))
+                );
+                claims.computeIfAbsent(claim.ownerId(), ignored -> new ArrayList<>()).add(claim);
+            }
+            for (Map<?, ?> entry : yaml.getMapList("notifications")) {
+                IssuerNotification notification = new IssuerNotification(
+                    UUID.fromString(requiredString(entry, "id")),
+                    UUID.fromString(requiredString(entry, "quest-id")),
+                    UUID.fromString(requiredString(entry, "recipient-id")),
+                    requiredString(entry, "message"),
+                    Instant.parse(requiredString(entry, "created-at"))
+                );
+                if (notifications.put(notification.id(), notification) != null) {
+                    throw new IllegalArgumentException(
+                        "Duplicate notification id: " + notification.id()
+                    );
+                }
+            }
         } catch (IllegalArgumentException | DateTimeParseException exception) {
             throw new IOException("Invalid quest record", exception);
         }
-        return new QuestState(quests);
+        return new QuestState(quests, claims, notifications);
     }
 
     @Override
@@ -72,20 +101,37 @@ final class YamlQuestRepository implements QuestRepository {
             serialized.put("created-at", quest.createdAt().toString());
             serialized.put("expires-at", quest.expiresAt().toString());
             serialized.put("status", quest.status().name());
-            List<Map<String, Object>> rewards = new ArrayList<>();
-            for (EscrowItem reward : quest.reward()) {
-                Map<String, Object> serializedReward = new LinkedHashMap<>();
-                serializedReward.put("material", reward.material());
-                serializedReward.put("amount", reward.amount());
-                if (reward.serializedItem() != null) {
-                    serializedReward.put("item-data", reward.serializedItem());
-                }
-                rewards.add(serializedReward);
-            }
-            serialized.put("reward", rewards);
+            serialized.put("reward", writeItems(quest.reward()));
             serializedQuests.add(serialized);
         }
         yaml.set("quests", serializedQuests);
+
+        List<Map<String, Object>> serializedClaims = new ArrayList<>();
+        for (List<QuestClaim> ownerClaims : state.claims().values()) {
+            for (QuestClaim claim : ownerClaims) {
+                Map<String, Object> serialized = new LinkedHashMap<>();
+                serialized.put("id", claim.id().toString());
+                serialized.put("quest-id", claim.questId().toString());
+                serialized.put("owner-id", claim.ownerId().toString());
+                serialized.put("created-at", claim.createdAt().toString());
+                serialized.put("source", claim.source().name());
+                serialized.put("items", writeItems(claim.items()));
+                serializedClaims.add(serialized);
+            }
+        }
+        yaml.set("claims", serializedClaims);
+
+        List<Map<String, Object>> serializedNotifications = new ArrayList<>();
+        for (IssuerNotification notification : state.notifications().values()) {
+            Map<String, Object> serialized = new LinkedHashMap<>();
+            serialized.put("id", notification.id().toString());
+            serialized.put("quest-id", notification.questId().toString());
+            serialized.put("recipient-id", notification.recipientId().toString());
+            serialized.put("message", notification.message());
+            serialized.put("created-at", notification.createdAt().toString());
+            serializedNotifications.add(serialized);
+        }
+        yaml.set("notifications", serializedNotifications);
         writeAtomically(yaml);
     }
 
@@ -106,24 +152,60 @@ final class YamlQuestRepository implements QuestRepository {
         }
     }
 
-    private static List<EscrowItem> readRewards(Object value) {
+    private static List<EscrowItem> readItems(Object value, String description) {
         if (!(value instanceof List<?> entries) || entries.isEmpty()) {
-            throw new IllegalArgumentException("Missing reward");
+            throw new IllegalArgumentException("Missing " + description);
         }
-        List<EscrowItem> rewards = new ArrayList<>();
+        List<EscrowItem> items = new ArrayList<>();
         for (Object rawEntry : entries) {
             if (!(rawEntry instanceof Map<?, ?> entry)) {
-                throw new IllegalArgumentException("Invalid reward");
+                throw new IllegalArgumentException("Invalid " + description);
             }
             Object data = entry.get("item-data");
             if (data != null && !(data instanceof String)) {
                 throw new IllegalArgumentException("Invalid item-data");
             }
-            rewards.add(new EscrowItem(
-                requiredString(entry, "material"), requiredInteger(entry, "amount"), (String) data
-            ));
+            Object customName = entry.get("custom-name");
+            if (customName != null && !(customName instanceof String)) {
+                throw new IllegalArgumentException("Invalid custom-name");
+            }
+            items.add(new EscrowItem(
+                requiredString(entry, "material"), requiredInteger(entry, "amount"),
+                (String) data, (String) customName
+            ).inferCustomName());
         }
-        return rewards;
+        return items;
+    }
+
+    private static List<Map<String, Object>> writeItems(List<EscrowItem> items) {
+        List<Map<String, Object>> serializedItems = new ArrayList<>();
+        for (EscrowItem item : items) {
+            Map<String, Object> serialized = new LinkedHashMap<>();
+            serialized.put("material", item.material());
+            serialized.put("amount", item.amount());
+            if (item.serializedItem() != null) {
+                serialized.put("item-data", item.serializedItem());
+            }
+            if (item.customName() != null) {
+                serialized.put("custom-name", item.customName());
+            }
+            serializedItems.add(serialized);
+        }
+        return serializedItems;
+    }
+
+    private static QuestClaimSource readClaimSource(Object value, Quest quest) {
+        if (value instanceof String source) {
+            return QuestClaimSource.valueOf(source);
+        }
+        if (value != null) {
+            throw new IllegalArgumentException("Invalid claim source");
+        }
+        if (quest == null || quest.status() == QuestStatus.COMPLETED) {
+            return QuestClaimSource.COMPLETION;
+        }
+        return quest.status() == QuestStatus.EXPIRED
+            ? QuestClaimSource.EXPIRATION : QuestClaimSource.CANCELLATION;
     }
 
     private static QuestStatus readStatus(Object value) {

src/main/resources/plugin.yml

@@ -10,7 +10,7 @@ commands:
     usage: /quests [list|create|complete|cancel|claim]
   questadmin:
     description: Administer Spigot Quest Board.
-    usage: /questadmin <createboard|commands>
+    usage: /questadmin <createboard [physical]|commands>
     permission: spigotquestboard.admin
 permissions:
   spigotquestboard.admin:

src/test/java/games/dmg/spigotquestboard/BoardRegistryTest.java

@@ -26,6 +26,40 @@ final class BoardRegistryTest {
         assertEquals(Set.of(BOARD), repository.saved.boards());
     }
 
+    @Test
+    void registersManyLocationsInOneRepositorySave() throws IOException {
+        RegisteredBoard second = new RegisteredBoard(
+            new BoardId(BOARD.id().worldId(), 2, 64, 2), "world"
+        );
+        RecordingRepository repository = new RecordingRepository(BoardState.empty());
+        BoardRegistry registry = new BoardRegistry(repository);
+
+        assertEquals(
+            BoardRegistrationResult.CREATED,
+            registry.registerAll(Set.of(BOARD, second))
+        );
+
+        assertEquals(1, repository.saveCount);
+        assertEquals(Set.of(BOARD, second), repository.saved.boards());
+        assertTrue(registry.contains(BOARD.id()));
+        assertTrue(registry.contains(second.id()));
+    }
+
+    @Test
+    void duplicateInBatchPublishesAndPersistsNothing() throws IOException {
+        RegisteredBoard conflict = new RegisteredBoard(BOARD.id(), "renamed-world");
+        RecordingRepository repository = new RecordingRepository(new BoardState(Set.of(BOARD)));
+        BoardRegistry registry = new BoardRegistry(repository);
+
+        assertEquals(
+            BoardRegistrationResult.ALREADY_REGISTERED,
+            registry.registerAll(Set.of(conflict))
+        );
+
+        assertEquals(0, repository.saveCount);
+        assertEquals(1, registry.size());
+    }
+
     @Test
     void duplicateDoesNotWrite() throws IOException {
         RecordingRepository repository = new RecordingRepository(new BoardState(Set.of(BOARD)));
@@ -35,6 +69,24 @@ final class BoardRegistryTest {
         assertEquals(0, repository.saveCount);
     }
 
+    @Test
+    void proximityUsesSameWorldAndAcceptsExactFiveBlockBoundary() throws Exception {
+        RecordingRepository repository = new RecordingRepository(new BoardState(Set.of(BOARD)));
+        BoardRegistry registry = new BoardRegistry(repository);
+
+        assertTrue(registry.isWithin(
+            BOARD.id().worldId(), BOARD.id().x() + 3.0, BOARD.id().y() + 4.0,
+            BOARD.id().z(), 5.0
+        ));
+        assertFalse(registry.isWithin(
+            BOARD.id().worldId(), BOARD.id().x() + 3.01, BOARD.id().y() + 4.0,
+            BOARD.id().z(), 5.0
+        ));
+        assertFalse(registry.isWithin(
+            UUID.randomUUID(), BOARD.id().x(), BOARD.id().y(), BOARD.id().z(), 5.0
+        ));
+    }
+
     @Test
     void failedPersistenceDoesNotPublishBoard() throws Exception {
         BoardRepository repository = new BoardRepository() {

src/test/java/games/dmg/spigotquestboard/BukkitIssuerNotifierTest.java

@@ -0,0 +1,199 @@
+package games.dmg.spigotquestboard;
+
+import static org.junit.jupiter.api.Assertions.assertEquals;
+import static org.junit.jupiter.api.Assertions.assertTrue;
+import static org.mockito.ArgumentMatchers.contains;
+import static org.mockito.Mockito.mock;
+import static org.mockito.Mockito.clearInvocations;
+import static org.mockito.Mockito.never;
+import static org.mockito.Mockito.times;
+import static org.mockito.Mockito.verify;
+import static org.mockito.Mockito.when;
+
+import java.time.Clock;
+import java.time.Instant;
+import java.time.ZoneOffset;
+import java.util.List;
+import java.util.UUID;
+import java.util.logging.Logger;
+import org.bukkit.Server;
+import org.bukkit.entity.Player;
+import org.bukkit.event.player.PlayerJoinEvent;
+import org.junit.jupiter.api.Test;
+
+final class BukkitIssuerNotifierTest {
+    @Test
+    void onlineIssuerIsNotifiedImmediatelyAndDurablePendingStateIsCleared() throws Exception {
+        Repository repository = new Repository();
+        QuestService service = completedService(repository);
+        UUID issuer = service.state().notifications().values().iterator().next().recipientId();
+        Server server = mock(Server.class);
+        Player player = mock(Player.class);
+        when(server.getPlayer(issuer)).thenReturn(player);
+        when(player.isOnline()).thenReturn(true);
+        when(player.getUniqueId()).thenReturn(issuer);
+        BukkitIssuerNotifier notifier = new BukkitIssuerNotifier(
+            service, server, Logger.getAnonymousLogger()
+        );
+
+        notifier.notifyIfOnline(issuer);
+
+        verify(player).sendMessage(contains("can be claimed at a quest board"));
+        assertTrue(service.state().notifications().isEmpty());
+        assertTrue(repository.state.notifications().isEmpty());
+    }
+
+    @Test
+    void failedNotificationAcknowledgementRemainsPendingForRetry() throws Exception {
+        Repository repository = new Repository();
+        QuestService service = completedService(repository);
+        IssuerNotification notification = service.state().notifications().values().iterator().next();
+        Server server = mock(Server.class);
+        Player player = mock(Player.class);
+        when(server.getPlayer(notification.recipientId())).thenReturn(player);
+        when(player.isOnline()).thenReturn(true);
+        when(player.getUniqueId()).thenReturn(notification.recipientId());
+        BukkitIssuerNotifier notifier = new BukkitIssuerNotifier(
+            service, server, Logger.getAnonymousLogger()
+        );
+        repository.fail = true;
+
+        notifier.notifyIfOnline(notification.recipientId());
+        assertEquals(1, service.pendingNotifications(notification.recipientId()).size());
+
+        repository.fail = false;
+        notifier.notifyIfOnline(notification.recipientId());
+        assertTrue(service.pendingNotifications(notification.recipientId()).isEmpty());
+    }
+
+    @Test
+    void offlineNotificationRemainsDurableUntilNextLogin() throws Exception {
+        Repository repository = new Repository();
+        QuestService service = completedService(repository);
+        IssuerNotification notification = service.state().notifications().values().iterator().next();
+        Server server = mock(Server.class);
+        when(server.getPlayer(notification.recipientId())).thenReturn(null);
+        BukkitIssuerNotifier notifier = new BukkitIssuerNotifier(
+            service, server, Logger.getAnonymousLogger()
+        );
+
+        notifier.notifyIfOnline(notification.recipientId());
+        assertEquals(1, service.state().notifications().size());
+
+        Player player = mock(Player.class);
+        when(player.getUniqueId()).thenReturn(notification.recipientId());
+        notifier.deliver(player);
+
+        verify(player).sendMessage(notification.message());
+        assertTrue(service.state().notifications().isEmpty());
+    }
+
+    @Test
+    void everyLoginReportsAvailableQuestsWithNaturalWordingAndBoardHint() throws Exception {
+        QuestService service = new QuestService(new Repository());
+        Instant now = Instant.EPOCH.plusSeconds(604800);
+        BukkitIssuerNotifier notifier = new BukkitIssuerNotifier(
+            service, mock(Server.class), Logger.getAnonymousLogger(),
+            Clock.fixed(now, ZoneOffset.UTC)
+        );
+        Player player = mock(Player.class);
+        when(player.getUniqueId()).thenReturn(UUID.randomUUID());
+        PlayerJoinEvent event = mock(PlayerJoinEvent.class);
+        when(event.getPlayer()).thenReturn(player);
+        String hint = " Visit the quest board to accept or create a quest.";
+
+        // Expired at exactly login time, even before the expiry task runs.
+        createQuest(service, Instant.EPOCH);
+        Quest completed = createQuest(service, now);
+        service.complete(completed.id(), new EscrowItem("STONE", 1, null), now);
+        Quest cancelled = createQuest(service, now);
+        service.cancel(cancelled.id(), cancelled.issuerId(), now);
+        notifier.onPlayerJoin(event);
+        verify(player).sendMessage("No quests are currently available." + hint);
+
+        createQuest(service, now);
+        notifier.onPlayerJoin(event);
+        verify(player).sendMessage("1 quest is currently available." + hint);
+
+        createQuest(service, now);
+        notifier.onPlayerJoin(event);
+        notifier.onPlayerJoin(event);
+        verify(player, times(2)).sendMessage("2 quests are currently available." + hint);
+        verify(player, never()).sendMessage(contains("items waiting"));
+    }
+
+    @Test
+    void claimsAreRemindedOnEveryLoginAcrossReloadsUntilAllCollected() throws Exception {
+        Repository repository = new Repository();
+        QuestService service = completedService(repository);
+        UUID issuer = service.state().notifications().values().iterator().next().recipientId();
+        Quest cancelled = service.create(
+            issuer, "Issuer", "STONE", 1,
+            List.of(new EscrowItem("DIAMOND", 1, null)), Instant.EPOCH
+        );
+        service.cancel(cancelled.id(), issuer, Instant.EPOCH.plusSeconds(1));
+        Player player = mock(Player.class);
+        when(player.getUniqueId()).thenReturn(issuer);
+        PlayerJoinEvent event = mock(PlayerJoinEvent.class);
+        when(event.getPlayer()).thenReturn(player);
+        String reminder = "You have items waiting to be claimed. "
+            + "Visit the quest board to collect them.";
+        BukkitIssuerNotifier notifier = new BukkitIssuerNotifier(
+            service, mock(Server.class), Logger.getAnonymousLogger()
+        );
+        notifier.onPlayerJoin(event);
+        notifier.onPlayerJoin(event);
+        verify(player, times(2)).sendMessage(reminder);
+        assertTrue(service.pendingNotifications(issuer).isEmpty());
+        assertEquals(2, service.claimsFor(issuer).size());
+
+        service = new QuestService(repository);
+        notifier = new BukkitIssuerNotifier(service, mock(Server.class), Logger.getAnonymousLogger());
+        notifier.onPlayerJoin(event);
+        verify(player, times(3)).sendMessage(reminder);
+        service.acknowledgeClaim(issuer, service.claimsFor(issuer).getFirst().id());
+        notifier.onPlayerJoin(event);
+        verify(player, times(4)).sendMessage(reminder);
+
+        clearInvocations(player);
+        when(player.getUniqueId()).thenReturn(UUID.randomUUID());
+        notifier.onPlayerJoin(event);
+        verify(player, never()).sendMessage(reminder);
+        when(player.getUniqueId()).thenReturn(issuer);
+        service.acknowledgeClaim(issuer, service.claimsFor(issuer).getFirst().id());
+        notifier.onPlayerJoin(event);
+        verify(player, never()).sendMessage(reminder);
+    }
+
+    private static Quest createQuest(QuestService service, Instant now) throws Exception {
+        return service.create(
+            UUID.randomUUID(), "Issuer", "STONE", 1,
+            List.of(new EscrowItem("DIAMOND", 1, null)), now
+        );
+    }
+
+    private static QuestService completedService(Repository repository) throws Exception {
+        QuestService service = new QuestService(repository);
+        Quest quest = service.create(
+            UUID.randomUUID(), "Issuer", "STONE", 1,
+            List.of(new EscrowItem("DIAMOND", 1, null)), Instant.EPOCH
+        );
+        service.complete(
+            quest.id(), new EscrowItem("STONE", 1, null), Instant.EPOCH.plusSeconds(1)
+        );
+        return service;
+    }
+
+    private static final class Repository implements QuestRepository {
+        private QuestState state = QuestState.empty();
+        private boolean fail;
+        @Override public QuestState load() { return state; }
+        @Override
+        public void save(QuestState candidate) throws java.io.IOException {
+            if (fail) {
+                throw new java.io.IOException("disk full");
+            }
+            state = candidate;
+        }
+    }
+}

src/test/java/games/dmg/spigotquestboard/BukkitItemMaterialCatalogTest.java

@@ -0,0 +1,100 @@
+package games.dmg.spigotquestboard;
+
+import static org.junit.jupiter.api.Assertions.assertEquals;
+import static org.junit.jupiter.api.Assertions.assertTrue;
+
+import java.util.Optional;
+import org.bukkit.Material;
+import org.junit.jupiter.api.AfterEach;
+import org.junit.jupiter.api.BeforeEach;
+import org.junit.jupiter.api.Test;
+import org.mockito.MockedStatic;
+import org.mockito.Mockito;
+
+final class BukkitItemMaterialCatalogTest {
+    private final BukkitItemMaterialCatalog catalog = new BukkitItemMaterialCatalog();
+
+    private MockedStatic<Material> materials;
+
+    @BeforeEach
+    void provideServerMaterialProperties() {
+        // Purpur delegates material properties to server-only registries.
+        String[] names = {"SHULKER_SHELL", "SHULKER_BOX", "STONE", "AIR", "CAVE_AIR", "VOID_AIR", "WATER", "FIRE"};
+        Material[] fixtures = new Material[names.length];
+        for (int i = 0; i < names.length; i++) {
+            Material material = Mockito.mock(Material.class);
+            Mockito.when(material.name()).thenReturn(names[i]);
+            Mockito.when(material.isItem()).thenReturn(i <= 3);
+            Mockito.when(material.isBlock()).thenReturn(i != 0);
+            Mockito.when(material.isAir()).thenReturn(i >= 3 && i <= 5);
+            fixtures[i] = material;
+        }
+        materials = Mockito.mockStatic(Material.class);
+        materials.when(Material::values).thenReturn(fixtures);
+        for (int i = 0; i < names.length; i++) {
+            String name = names[i];
+            Material material = fixtures[i];
+            materials.when(() -> Material.matchMaterial(name)).thenReturn(material);
+            materials.when(() -> Material.matchMaterial(name.toLowerCase(java.util.Locale.ROOT)))
+                .thenReturn(material);
+        }
+    }
+
+    @AfterEach
+    void closeMaterialFixtures() {
+        materials.close();
+    }
+
+    @Test
+    void acceptsShellsAndExistingBlockItems() {
+        assertEquals(Optional.of("SHULKER_SHELL"), catalog.normalizeItem("shulker_shell"));
+        assertEquals(Optional.of("SHULKER_BOX"), catalog.normalizeItem("shulker_box"));
+        assertEquals(Optional.of("STONE"), catalog.normalizeItem("stone"));
+    }
+
+    @Test
+    void rejectsAirInvalidAndNonItemMaterials() {
+        for (String input : new String[] {"AIR", "CAVE_AIR", "VOID_AIR", "WATER", "FIRE", "invalid", ""}) {
+            assertTrue(catalog.normalizeItem(input).isEmpty(), input);
+        }
+        assertTrue(catalog.normalizeItem(null).isEmpty());
+    }
+
+    @Test
+    void createsPersistsAndSettlesShellRequest(@org.junit.jupiter.api.io.TempDir java.nio.file.Path directory)
+        throws Exception {
+        QuestRepository repository = new YamlQuestRepository(directory.resolve("quests.yml"));
+        QuestService service = new QuestService(repository);
+        org.bukkit.entity.Player player = Mockito.mock(org.bukkit.entity.Player.class);
+        java.util.UUID issuer = java.util.UUID.randomUUID();
+        Mockito.when(player.getUniqueId()).thenReturn(issuer);
+        Mockito.when(player.getName()).thenReturn("Issuer");
+        EscrowItem reward = new EscrowItem("DIAMOND", 1, null);
+        HeldRewardInventory inventory = ignored -> new HeldRewardInventory.RemovedReward() {
+            @Override public EscrowItem item() { return reward; }
+            @Override public void rollback() { throw new AssertionError("Unexpected rollback"); }
+        };
+        QuestCreationController controller = new QuestCreationController(service, catalog, inventory);
+        assertTrue(controller.suggestItemMaterials("shulker_").contains("SHULKER_SHELL"));
+        Quest quest = controller.create(player, "shulker_shell", 16, java.time.Instant.EPOCH);
+        service = new QuestService(repository);
+        EscrowItem delivery = new EscrowItem("SHULKER_SHELL", 16, null);
+        QuestCompletion completion = service.complete(
+            quest.id(), delivery, java.time.Instant.EPOCH.plusSeconds(1)
+        );
+        assertEquals(java.util.List.of(reward), completion.reward());
+        service = new QuestService(repository);
+        QuestClaim claim = service.claimsFor(issuer).getFirst();
+        assertEquals(java.util.List.of(delivery), claim.items());
+        assertEquals(QuestStatus.COMPLETED, service.state().quests().get(quest.id()).status());
+        service.acknowledgeClaim(issuer, claim.id());
+        assertTrue(new QuestService(repository).claimsFor(issuer).isEmpty());
+    }
+
+    @Test
+    void suggestsShellsAndBoxesButNotNonItems() {
+        assertTrue(catalog.suggest("shulker_").contains("SHULKER_SHELL"));
+        assertTrue(catalog.suggest("shulker_").contains("SHULKER_BOX"));
+        assertTrue(catalog.suggest("WATER").stream().noneMatch("WATER"::equals));
+    }
+}

src/test/java/games/dmg/spigotquestboard/BukkitPhysicalBoardWorldTest.java

@@ -0,0 +1,172 @@
+package games.dmg.spigotquestboard;
+
+import static org.junit.jupiter.api.Assertions.assertEquals;
+import static org.junit.jupiter.api.Assertions.assertFalse;
+import static org.junit.jupiter.api.Assertions.assertTrue;
+import static org.mockito.ArgumentMatchers.any;
+import static org.mockito.Mockito.mock;
+import static org.mockito.Mockito.times;
+import static org.mockito.Mockito.verify;
+import static org.mockito.Mockito.when;
+
+import java.util.List;
+import java.util.UUID;
+import net.kyori.adventure.text.Component;
+import net.kyori.adventure.text.format.TextDecoration;
+import org.bukkit.Material;
+import org.bukkit.World;
+import org.bukkit.block.Block;
+import org.bukkit.block.BlockState;
+import org.bukkit.block.Sign;
+import org.bukkit.block.data.type.WallSign;
+import org.bukkit.block.sign.Side;
+import org.bukkit.block.sign.SignSide;
+import org.junit.jupiter.api.Test;
+import org.mockito.ArgumentCaptor;
+
+final class BukkitPhysicalBoardWorldTest {
+    @Test
+    void configuresWallSignFacingAndDecorativeObfuscatedText() {
+        UUID worldId = UUID.randomUUID();
+        BoardId location = new BoardId(worldId, 1, 65, 2);
+        World world = mock(World.class);
+        Block block = mock(Block.class);
+        WallSign wallSign = mock(WallSign.class);
+        Sign sign = mock(Sign.class);
+        SignSide signSide = mock(SignSide.class);
+        when(world.getUID()).thenReturn(worldId);
+        when(world.getBlockAt(1, 65, 2)).thenReturn(block);
+        when(block.getBlockData()).thenReturn(wallSign);
+        when(block.getState()).thenReturn(sign);
+        when(sign.getSide(Side.FRONT)).thenReturn(signSide);
+        when(sign.update(true, false)).thenReturn(true);
+        BukkitPhysicalBoardWorld adapter = new BukkitPhysicalBoardWorld(world);
+
+        adapter.place(
+            new PhysicalBoardPlan.Placement(location, "OAK_WALL_SIGN"),
+            BoardFacing.NORTH
+        );
+
+        verify(block).setType(Material.OAK_WALL_SIGN, false);
+        verify(wallSign).setFacing(org.bukkit.block.BlockFace.NORTH);
+        verify(block).setBlockData(wallSign, false);
+        ArgumentCaptor<Component> text = ArgumentCaptor.forClass(Component.class);
+        verify(signSide, times(4)).line(any(Integer.class), text.capture());
+        assertEquals(4, text.getAllValues().size());
+        assertTrue(text.getAllValues().stream().allMatch(component ->
+            component.decoration(TextDecoration.OBFUSCATED) == TextDecoration.State.TRUE
+        ));
+    }
+
+    @Test
+    void matchesOnlyAnExactDecorativeSignForLegacyIdentification() {
+        UUID worldId = UUID.randomUUID();
+        BoardId location = new BoardId(worldId, 1, 65, 2);
+        World world = mock(World.class);
+        Block block = mock(Block.class);
+        WallSign wallSign = mock(WallSign.class);
+        Sign sign = mock(Sign.class);
+        SignSide signSide = mock(SignSide.class);
+        when(world.getUID()).thenReturn(worldId);
+        when(world.getBlockAt(1, 65, 2)).thenReturn(block);
+        when(block.getType()).thenReturn(Material.OAK_WALL_SIGN);
+        when(block.getBlockData()).thenReturn(wallSign);
+        when(block.getState()).thenReturn(sign);
+        when(wallSign.getFacing()).thenReturn(org.bukkit.block.BlockFace.NORTH);
+        when(sign.getSide(Side.FRONT)).thenReturn(signSide);
+        List<Component> decorative = BukkitPhysicalBoardWorld.signLines(
+            PhysicalBoardSignKind.DECORATIVE
+        );
+        for (int line = 0; line < decorative.size(); line++) {
+            when(signSide.line(line)).thenReturn(decorative.get(line));
+        }
+        BukkitPhysicalBoardWorld adapter = new BukkitPhysicalBoardWorld(world);
+        PhysicalBoardPlan.Placement placement = new PhysicalBoardPlan.Placement(
+            location, "OAK_WALL_SIGN", PhysicalBoardSignKind.DECORATIVE
+        );
+
+        assertTrue(adapter.matches(placement, BoardFacing.NORTH));
+        assertFalse(adapter.matches(placement, BoardFacing.SOUTH));
+    }
+
+    @Test
+    void readableSignsGlowWhileDecorativeSignsDoNot() {
+        UUID worldId = UUID.randomUUID();
+        BoardId location = new BoardId(worldId, 1, 65, 2);
+        World world = mock(World.class);
+        Block block = mock(Block.class);
+        WallSign wallSign = mock(WallSign.class);
+        Sign sign = mock(Sign.class);
+        SignSide signSide = mock(SignSide.class);
+        when(world.getUID()).thenReturn(worldId);
+        when(world.getBlockAt(1, 65, 2)).thenReturn(block);
+        when(block.getBlockData()).thenReturn(wallSign);
+        when(block.getState()).thenReturn(sign);
+        when(sign.getSide(Side.FRONT)).thenReturn(signSide);
+        when(sign.update(true, false)).thenReturn(true);
+        BukkitPhysicalBoardWorld adapter = new BukkitPhysicalBoardWorld(world);
+
+        adapter.place(new PhysicalBoardPlan.Placement(
+            location, "OAK_WALL_SIGN", PhysicalBoardSignKind.TITLE
+        ), BoardFacing.NORTH);
+        verify(signSide).setGlowingText(true);
+
+        adapter.place(new PhysicalBoardPlan.Placement(
+            location, "OAK_WALL_SIGN", PhysicalBoardSignKind.DECORATIVE
+        ), BoardFacing.NORTH);
+        verify(signSide).setGlowingText(false);
+    }
+
+    @Test
+    void rendersReadableTitleAndInstructionText() {
+        assertEquals(
+            List.of(Component.text("Quest"), Component.text("Board"),
+                Component.empty(), Component.empty()),
+            placedLines(PhysicalBoardSignKind.TITLE)
+        );
+        assertEquals(
+            List.of(Component.text("Right-click"), Component.text("a sign below"),
+                Component.text("to browse"), Component.text("quests")),
+            placedLines(PhysicalBoardSignKind.INSTRUCTION)
+        );
+    }
+
+    private static List<Component> placedLines(PhysicalBoardSignKind kind) {
+        UUID worldId = UUID.randomUUID();
+        BoardId location = new BoardId(worldId, 1, 65, 2);
+        World world = mock(World.class);
+        Block block = mock(Block.class);
+        WallSign wallSign = mock(WallSign.class);
+        Sign sign = mock(Sign.class);
+        SignSide signSide = mock(SignSide.class);
+        when(world.getUID()).thenReturn(worldId);
+        when(world.getBlockAt(1, 65, 2)).thenReturn(block);
+        when(block.getBlockData()).thenReturn(wallSign);
+        when(block.getState()).thenReturn(sign);
+        when(sign.getSide(Side.FRONT)).thenReturn(signSide);
+        when(sign.update(true, false)).thenReturn(true);
+
+        new BukkitPhysicalBoardWorld(world).place(
+            new PhysicalBoardPlan.Placement(location, "OAK_WALL_SIGN", kind),
+            BoardFacing.NORTH
+        );
+
+        ArgumentCaptor<Component> text = ArgumentCaptor.forClass(Component.class);
+        verify(signSide, times(4)).line(any(Integer.class), text.capture());
+        return text.getAllValues();
+    }
+
+    @Test
+    void restoresCapturedBukkitBlockState() {
+        UUID worldId = UUID.randomUUID();
+        BoardId location = new BoardId(worldId, 1, 65, 2);
+        World world = mock(World.class);
+        BlockState snapshot = mock(BlockState.class);
+        when(world.getUID()).thenReturn(worldId);
+        when(snapshot.update(true, false)).thenReturn(true);
+
+        new BukkitPhysicalBoardWorld(world).restore(location, snapshot);
+
+        verify(snapshot).update(true, false);
+    }
+}

src/test/java/games/dmg/spigotquestboard/BukkitQuestClaimInventoryTest.java

@@ -0,0 +1,94 @@
+package games.dmg.spigotquestboard;
+
+import static org.junit.jupiter.api.Assertions.assertEquals;
+import static org.junit.jupiter.api.Assertions.assertThrows;
+import static org.mockito.ArgumentMatchers.any;
+import static org.mockito.Mockito.doThrow;
+import static org.mockito.Mockito.mock;
+import static org.mockito.Mockito.verify;
+import static org.mockito.Mockito.when;
+
+import java.util.HashMap;
+import java.util.List;
+import java.util.UUID;
+import org.bukkit.Location;
+import org.bukkit.World;
+import org.bukkit.entity.Item;
+import org.bukkit.entity.Player;
+import org.bukkit.inventory.ItemStack;
+import org.bukkit.inventory.PlayerInventory;
+import org.junit.jupiter.api.Test;
+
+final class BukkitQuestClaimInventoryTest {
+    @Test
+    void inventoryOverflowIsDroppedAtFeetWithOwnerProtection() {
+        UUID owner = UUID.randomUUID();
+        Player player = mock(Player.class);
+        PlayerInventory inventory = mock(PlayerInventory.class);
+        World world = mock(World.class);
+        Location feet = mock(Location.class);
+        Item dropped = mock(Item.class);
+        ItemStack requested = mock(ItemStack.class);
+        ItemStack requestedCopy = mock(ItemStack.class);
+        ItemStack leftover = mock(ItemStack.class);
+        ItemStack leftoverCopy = mock(ItemStack.class);
+        when(requested.clone()).thenReturn(requestedCopy);
+        when(leftover.clone()).thenReturn(leftoverCopy);
+        when(leftover.getAmount()).thenReturn(2);
+        when(player.getUniqueId()).thenReturn(owner);
+        when(player.getInventory()).thenReturn(inventory);
+        when(player.getWorld()).thenReturn(world);
+        when(player.getLocation()).thenReturn(feet);
+        when(inventory.getStorageContents()).thenReturn(new ItemStack[36]);
+        HashMap<Integer, ItemStack> leftovers = new HashMap<>();
+        leftovers.put(0, leftover);
+        when(inventory.addItem(any(ItemStack.class))).thenReturn(leftovers);
+        when(world.dropItem(any(Location.class), any(ItemStack.class))).thenReturn(dropped);
+
+        QuestClaimInventory.Delivery delivery = BukkitQuestClaimInventory.deliver(
+            player, List.of(requested)
+        );
+
+        assertEquals(2, delivery.overflowAmount());
+        verify(world).dropItem(feet, leftoverCopy);
+        verify(dropped).setOwner(owner);
+    }
+
+    @Test
+    void ownerProtectionFailureRestoresInventoryAndRemovesPartialDrop() {
+        Player player = mock(Player.class);
+        PlayerInventory inventory = mock(PlayerInventory.class);
+        World world = mock(World.class);
+        Location feet = mock(Location.class);
+        Item dropped = mock(Item.class);
+        ItemStack requested = mock(ItemStack.class);
+        ItemStack requestedCopy = mock(ItemStack.class);
+        ItemStack leftover = mock(ItemStack.class);
+        ItemStack leftoverCopy = mock(ItemStack.class);
+        ItemStack existing = mock(ItemStack.class);
+        ItemStack existingCopy = mock(ItemStack.class);
+        when(requested.clone()).thenReturn(requestedCopy);
+        when(leftover.clone()).thenReturn(leftoverCopy);
+        when(existing.clone()).thenReturn(existingCopy);
+        when(existingCopy.clone()).thenReturn(existingCopy);
+        ItemStack[] original = new ItemStack[] {existing};
+        when(player.getInventory()).thenReturn(inventory);
+        when(player.getWorld()).thenReturn(world);
+        when(player.getLocation()).thenReturn(feet);
+        when(player.getUniqueId()).thenReturn(UUID.randomUUID());
+        when(inventory.getStorageContents()).thenReturn(original);
+        HashMap<Integer, ItemStack> leftovers = new HashMap<>();
+        leftovers.put(0, leftover);
+        when(inventory.addItem(requestedCopy)).thenReturn(leftovers);
+        when(world.dropItem(any(Location.class), any(ItemStack.class))).thenReturn(dropped);
+        doThrow(new IllegalStateException("owner rejected")).when(dropped).setOwner(any());
+
+        assertThrows(
+            IllegalStateException.class,
+            () -> BukkitQuestClaimInventory.deliver(player, List.of(requested))
+        );
+
+        verify(inventory).setStorageContents(any(ItemStack[].class));
+        verify(dropped).remove();
+    }
+}

src/test/java/games/dmg/spigotquestboard/EscrowItemTest.java

@@ -0,0 +1,82 @@
+package games.dmg.spigotquestboard;
+
+import static org.junit.jupiter.api.Assertions.assertArrayEquals;
+import static org.junit.jupiter.api.Assertions.assertEquals;
+import static org.junit.jupiter.api.Assertions.assertNull;
+import static org.junit.jupiter.api.Assertions.assertThrows;
+import static org.mockito.Mockito.mock;
+import static org.mockito.Mockito.when;
+
+import java.util.Base64;
+import net.kyori.adventure.text.Component;
+import net.kyori.adventure.text.format.NamedTextColor;
+import net.kyori.adventure.text.format.TextDecoration;
+import org.bukkit.Material;
+import org.bukkit.inventory.ItemStack;
+import org.bukkit.inventory.meta.ItemMeta;
+import org.junit.jupiter.api.Test;
+import org.mockito.MockedStatic;
+import org.mockito.Mockito;
+
+final class EscrowItemTest {
+    @Test
+    void capturesStyledCustomNameAsSafePlainTextWithoutChangingSerializedBytes() {
+        byte[] exactBytes = new byte[] {1, 2, 3, 4};
+        ItemStack original = mock(ItemStack.class);
+        ItemStack snapshot = mock(ItemStack.class);
+        ItemMeta metadata = mock(ItemMeta.class);
+        when(original.getType()).thenReturn(Material.PAPER);
+        when(original.getAmount()).thenReturn(2);
+        when(original.clone()).thenReturn(snapshot);
+        when(snapshot.getType()).thenReturn(Material.PAPER);
+        when(snapshot.getAmount()).thenReturn(2);
+        when(snapshot.serializeAsBytes()).thenReturn(exactBytes);
+        when(snapshot.hasItemMeta()).thenReturn(true);
+        when(snapshot.getItemMeta()).thenReturn(metadata);
+        when(metadata.hasCustomName()).thenReturn(true);
+        when(metadata.customName()).thenReturn(
+            Component.text("  Shopping", NamedTextColor.GOLD, TextDecoration.BOLD)
+                .append(Component.text("\nList  ", NamedTextColor.BLUE))
+        );
+
+        EscrowItem escrow = EscrowItem.fromItemStack(original);
+
+        assertEquals("Shopping List", escrow.customName());
+        assertArrayEquals(exactBytes, Base64.getDecoder().decode(escrow.serializedItem()));
+    }
+
+    @Test
+    void ignoresVanillaDisplayNameWhenNoTrueCustomNameExists() {
+        ItemStack original = mock(ItemStack.class);
+        ItemStack snapshot = mock(ItemStack.class);
+        ItemMeta metadata = mock(ItemMeta.class);
+        when(original.getType()).thenReturn(Material.DIAMOND);
+        when(original.getAmount()).thenReturn(3);
+        when(original.clone()).thenReturn(snapshot);
+        when(snapshot.getType()).thenReturn(Material.DIAMOND);
+        when(snapshot.getAmount()).thenReturn(3);
+        when(snapshot.serializeAsBytes()).thenReturn(new byte[] {9});
+        when(snapshot.hasItemMeta()).thenReturn(true);
+        when(snapshot.getItemMeta()).thenReturn(metadata);
+        when(metadata.hasCustomName()).thenReturn(false);
+
+        assertNull(EscrowItem.fromItemStack(original).customName());
+    }
+
+    @Test
+    void historicalInferenceDoesNotWeakenExactEnvelopeValidation() {
+        String data = Base64.getEncoder().encodeToString(new byte[] {7});
+        EscrowItem escrow = new EscrowItem("PAPER", 1, data);
+        ItemStack mismatched = mock(ItemStack.class);
+        when(mismatched.getType()).thenReturn(Material.BOOK);
+        when(mismatched.getAmount()).thenReturn(1);
+
+        try (MockedStatic<ItemStack> itemStacks = Mockito.mockStatic(ItemStack.class)) {
+            itemStacks.when(() -> ItemStack.deserializeBytes(Mockito.any(byte[].class)))
+                .thenReturn(mismatched);
+
+            assertEquals(escrow, escrow.inferCustomName());
+            assertThrows(IllegalStateException.class, escrow::toItemStack);
+        }
+    }
+}

src/test/java/games/dmg/spigotquestboard/PhysicalBoardCreatorTest.java

@@ -0,0 +1,167 @@
+package games.dmg.spigotquestboard;
+
+import static org.junit.jupiter.api.Assertions.assertEquals;
+import static org.junit.jupiter.api.Assertions.assertThrows;
+import static org.junit.jupiter.api.Assertions.assertTrue;
+import static org.mockito.Mockito.mock;
+import static org.mockito.Mockito.when;
+
+import java.io.IOException;
+import java.util.HashMap;
+import java.util.Map;
+import java.util.Set;
+import java.util.UUID;
+import org.bukkit.World;
+import org.bukkit.block.Block;
+import org.junit.jupiter.api.Test;
+
+final class PhysicalBoardCreatorTest {
+    private static final UUID WORLD_ID = UUID.fromString(
+        "00000000-0000-0000-0000-000000000010"
+    );
+    private static final BoardId ANCHOR = new BoardId(WORLD_ID, 10, 64, 20);
+
+    @Test
+    void buildsAndAtomicallyRegistersEveryVisiblePanelBlock() throws Exception {
+        RecordingRepository repository = new RecordingRepository(false);
+        BoardRegistry registry = new BoardRegistry(repository);
+        FakeWorld world = new FakeWorld();
+        PhysicalBoardCreator creator = creator(registry, world);
+
+        assertEquals(
+            PhysicalBoardCreationResult.CREATED,
+            creator.create(anchorBlock(), BoardFacing.NORTH)
+        );
+
+        assertEquals(25, world.placed.size());
+        assertEquals("AIR", world.materials.getOrDefault(ANCHOR, "AIR"));
+        assertEquals(17, registry.size());
+        assertEquals(17, repository.state.boards().size());
+        assertEquals(1, repository.saves);
+        assertTrue(repository.state.boards().stream().allMatch(
+            board -> board.worldName().equals("survival")
+        ));
+        assertTrue(PhysicalBoardPlan.create(ANCHOR, BoardFacing.NORTH)
+            .interactionLocations().stream().allMatch(location -> registry.isWithin(
+                location.worldId(), location.x(), location.y(), location.z(), 5.0
+            )));
+    }
+
+    @Test
+    void obstructionPreflightChangesAndRegistersNothing() throws Exception {
+        RecordingRepository repository = new RecordingRepository(false);
+        BoardRegistry registry = new BoardRegistry(repository);
+        FakeWorld world = new FakeWorld();
+        BoardId obstruction = PhysicalBoardPlan.create(ANCHOR, BoardFacing.EAST)
+            .placements().stream()
+            .filter(placement -> placement.signKind() == PhysicalBoardSignKind.TITLE)
+            .findFirst().orElseThrow().location();
+        world.materials.put(obstruction, "STONE");
+
+        assertEquals(
+            PhysicalBoardCreationResult.OBSTRUCTED,
+            creator(registry, world).create(anchorBlock(), BoardFacing.EAST)
+        );
+
+        assertTrue(world.placed.isEmpty());
+        assertEquals("STONE", world.materials.get(obstruction));
+        assertEquals(0, repository.saves);
+        assertEquals(0, registry.size());
+    }
+
+    @Test
+    void placementFailureRestoresEveryChangedBlockAndRegistersNothing() throws Exception {
+        RecordingRepository repository = new RecordingRepository(false);
+        BoardRegistry registry = new BoardRegistry(repository);
+        FakeWorld world = new FakeWorld();
+        world.failPlacement = 11;
+
+        assertThrows(IOException.class, () -> creator(registry, world).create(
+            anchorBlock(), BoardFacing.SOUTH
+        ));
+
+        assertTrue(world.materials.values().stream().allMatch("AIR"::equals));
+        assertEquals(0, repository.saves);
+        assertEquals(0, registry.size());
+    }
+
+    @Test
+    void persistenceFailureRestoresWholeStructureAndPublishesNothing() throws Exception {
+        RecordingRepository repository = new RecordingRepository(true);
+        BoardRegistry registry = new BoardRegistry(repository);
+        FakeWorld world = new FakeWorld();
+
+        assertThrows(IOException.class, () -> creator(registry, world).create(
+            anchorBlock(), BoardFacing.WEST
+        ));
+
+        assertTrue(world.materials.values().stream().allMatch("AIR"::equals));
+        assertEquals(1, repository.saves);
+        assertEquals(0, registry.size());
+    }
+
+    private static PhysicalBoardCreator creator(BoardRegistry registry, FakeWorld world) {
+        return new PhysicalBoardCreator(registry, ignored -> world);
+    }
+
+    private static Block anchorBlock() {
+        World world = mock(World.class);
+        when(world.getUID()).thenReturn(WORLD_ID);
+        when(world.getName()).thenReturn("survival");
+        Block block = mock(Block.class);
+        when(block.getWorld()).thenReturn(world);
+        when(block.getX()).thenReturn(ANCHOR.x());
+        when(block.getY()).thenReturn(ANCHOR.y());
+        when(block.getZ()).thenReturn(ANCHOR.z());
+        return block;
+    }
+
+    private static final class FakeWorld implements PhysicalBoardWorld {
+        private final Map<BoardId, String> materials = new HashMap<>();
+        private final Map<BoardId, String> placed = new HashMap<>();
+        private int placements;
+        private int failPlacement = -1;
+
+        @Override public boolean isEmpty(BoardId location) {
+            return "AIR".equals(materials.getOrDefault(location, "AIR"));
+        }
+
+        @Override public Object snapshot(BoardId location) {
+            return materials.getOrDefault(location, "AIR");
+        }
+
+        @Override public void place(PhysicalBoardPlan.Placement placement, BoardFacing facing) {
+            if (placements++ == failPlacement) {
+                throw new IllegalStateException("simulated sign configuration failure");
+            }
+            materials.put(placement.location(), placement.material());
+            placed.put(placement.location(), placement.material());
+        }
+
+        @Override public void restore(BoardId location, Object snapshot) {
+            materials.put(location, (String) snapshot);
+        }
+    }
+
+    private static final class RecordingRepository implements BoardRepository {
+        private BoardState state = new BoardState(Set.of());
+        private final boolean failSave;
+        private int saves;
+
+        private RecordingRepository(boolean failSave) {
+            this.failSave = failSave;
+        }
+
+        @Override public BoardState load() {
+            return state;
+        }
+
+        @Override public void save(BoardState state) throws IOException {
+            saves++;
+            if (failSave) {
+                throw new IOException("disk full");
+            }
+            this.state = state;
+        }
+    }
+}

src/test/java/games/dmg/spigotquestboard/PhysicalBoardPlanTest.java

@@ -0,0 +1,97 @@
+package games.dmg.spigotquestboard;
+
+import static org.junit.jupiter.api.Assertions.assertEquals;
+import static org.junit.jupiter.api.Assertions.assertFalse;
+import static org.junit.jupiter.api.Assertions.assertTrue;
+
+import java.util.HashSet;
+import java.util.UUID;
+import org.junit.jupiter.api.Test;
+
+final class PhysicalBoardPlanTest {
+    @Test
+    void createsFiveWideFourTallOakBoardAboveGroundAnchor() {
+        BoardId anchor = new BoardId(UUID.randomUUID(), 0, 64, 0);
+
+        PhysicalBoardPlan plan = PhysicalBoardPlan.create(anchor, BoardFacing.NORTH);
+
+        assertEquals(8, plan.placements().stream()
+            .filter(block -> block.material().equals("OAK_LOG")).count());
+        assertEquals(12, plan.placements().stream()
+            .filter(block -> block.material().equals("OAK_PLANKS")).count());
+        assertEquals(5, plan.placements().stream()
+            .filter(block -> block.material().equals("OAK_WALL_SIGN")).count());
+        assertEquals(17, plan.interactionLocations().size());
+        assertFalse(plan.placements().stream().anyMatch(block -> block.location().equals(anchor)));
+        assertEquals(-2, plan.placements().stream().mapToInt(block -> block.location().x()).min().orElseThrow());
+        assertEquals(2, plan.placements().stream().mapToInt(block -> block.location().x()).max().orElseThrow());
+        assertEquals(65, plan.placements().stream().mapToInt(block -> block.location().y()).min().orElseThrow());
+        assertEquals(68, plan.placements().stream().mapToInt(block -> block.location().y()).max().orElseThrow());
+    }
+
+    @Test
+    void rotatesWidthAndFrontMountedSignsForEveryFacing() {
+        BoardId anchor = new BoardId(UUID.randomUUID(), 10, 64, 20);
+
+        for (BoardFacing facing : BoardFacing.values()) {
+            PhysicalBoardPlan plan = PhysicalBoardPlan.create(anchor, facing);
+            assertEquals(25, plan.placements().size());
+            assertEquals(25, new HashSet<>(plan.placements().stream()
+                .map(PhysicalBoardPlan.Placement::location).toList()).size());
+
+            var backing = plan.placements().stream().filter(
+                placement -> !placement.sign()
+            ).toList();
+            assertEquals(20, backing.size());
+            assertTrue(backing.stream().allMatch(placement ->
+                forward(anchor, placement.location(), facing) == 0
+                    && Math.abs(lateral(anchor, placement.location(), facing)) <= 2
+                    && placement.location().y() >= anchor.y() + 1
+                    && placement.location().y() <= anchor.y() + 4
+            ));
+
+            var signs = plan.placements().stream().filter(
+                PhysicalBoardPlan.Placement::sign
+            ).toList();
+            assertEquals(5, signs.size());
+            assertTrue(signs.stream().allMatch(sign ->
+                forward(anchor, sign.location(), facing) == 1
+                    && Math.abs(lateral(anchor, sign.location(), facing)) <= 1
+                    && sign.location().y() >= anchor.y() + 2
+                    && sign.location().y() <= anchor.y() + 4
+            ));
+            assertEquals(1, signs.stream()
+                .filter(sign -> sign.signKind() == PhysicalBoardSignKind.TITLE).count());
+            assertEquals(1, signs.stream()
+                .filter(sign -> sign.signKind() == PhysicalBoardSignKind.INSTRUCTION).count());
+            assertEquals(3, signs.stream()
+                .filter(sign -> sign.signKind() == PhysicalBoardSignKind.DECORATIVE).count());
+            assertEquals(17, plan.interactionLocations().size());
+            assertTrue(plan.interactionLocations().containsAll(signs.stream()
+                .map(PhysicalBoardPlan.Placement::location).toList()));
+            assertTrue(backing.stream()
+                .filter(placement -> placement.material().equals("OAK_PLANKS"))
+                .allMatch(placement -> plan.interactionLocations().contains(
+                    placement.location()
+                )));
+        }
+    }
+
+    private static int forward(BoardId anchor, BoardId location, BoardFacing facing) {
+        return (location.x() - anchor.x()) * facing.x()
+            + (location.z() - anchor.z()) * facing.z();
+    }
+
+    private static int lateral(BoardId anchor, BoardId location, BoardFacing facing) {
+        return (location.x() - anchor.x()) * facing.rightX()
+            + (location.z() - anchor.z()) * facing.rightZ();
+    }
+
+    @Test
+    void boardFrontFacesOppositeTheAdministratorsLookDirection() {
+        assertEquals(BoardFacing.SOUTH, BoardFacing.towardPlayer(org.bukkit.block.BlockFace.NORTH));
+        assertEquals(BoardFacing.WEST, BoardFacing.towardPlayer(org.bukkit.block.BlockFace.EAST));
+        assertEquals(BoardFacing.NORTH, BoardFacing.towardPlayer(org.bukkit.block.BlockFace.SOUTH));
+        assertEquals(BoardFacing.EAST, BoardFacing.towardPlayer(org.bukkit.block.BlockFace.WEST));
+    }
+}

src/test/java/games/dmg/spigotquestboard/PhysicalBoardUpgraderTest.java

@@ -0,0 +1,303 @@
+package games.dmg.spigotquestboard;
+
+import static org.junit.jupiter.api.Assertions.assertEquals;
+import static org.junit.jupiter.api.Assertions.assertThrows;
+import static org.junit.jupiter.api.Assertions.assertTrue;
+
+import java.io.IOException;
+import java.util.HashMap;
+import java.util.Map;
+import java.util.Set;
+import java.util.UUID;
+import java.util.stream.Collectors;
+import org.junit.jupiter.api.Test;
+
+final class PhysicalBoardUpgraderTest {
+    private static final UUID WORLD_ID = UUID.fromString(
+        "00000000-0000-0000-0000-000000000011"
+    );
+    private static final BoardId ANCHOR = new BoardId(WORLD_ID, 10, 64, 20);
+    private static final BoardFacing FACING = BoardFacing.NORTH;
+
+    @Test
+    void upgradesOnlyAnExactRegisteredLegacyStructure() throws Exception {
+        RecordingRepository repository = new RecordingRepository(legacyRegistrations(), false);
+        BoardRegistry registry = new BoardRegistry(repository);
+        FakeWorld world = legacyWorld();
+
+        assertEquals(1, upgrader(registry, world).upgrade());
+
+        assertEquals(17, registry.size());
+        assertEquals(1, repository.saves);
+        assertEquals(Set.of(PhysicalBoardSignKind.TITLE, PhysicalBoardSignKind.INSTRUCTION),
+            world.placed.values().stream().map(PhysicalBoardPlan.Placement::signKind)
+                .collect(Collectors.toSet()));
+        assertEquals(2, world.placed.size());
+    }
+
+    @Test
+    void refreshesBothReadableSignsOnAnExactRegisteredFullBoard() throws Exception {
+        RecordingRepository repository = new RecordingRepository(fullRegistrations(), false);
+        BoardRegistry registry = new BoardRegistry(repository);
+        FakeWorld world = fullWorld(false);
+
+        assertEquals(1, upgrader(registry, world).upgrade());
+
+        assertEquals(17, registry.size());
+        assertEquals(0, repository.saves);
+        assertEquals(Set.of(PhysicalBoardSignKind.TITLE, PhysicalBoardSignKind.INSTRUCTION),
+            world.placed.values().stream().map(PhysicalBoardPlan.Placement::signKind)
+                .collect(Collectors.toSet()));
+        assertTrue(newSigns().stream().allMatch(sign -> world.glowing.get(sign.location())));
+    }
+
+    @Test
+    void doesNotReportOrRefreshAnAlreadyGlowingFullBoard() throws Exception {
+        RecordingRepository repository = new RecordingRepository(fullRegistrations(), false);
+        FakeWorld world = fullWorld(true);
+
+        assertEquals(0, upgrader(new BoardRegistry(repository), world).upgrade());
+
+        assertTrue(world.placed.isEmpty());
+        assertEquals(0, repository.saves);
+    }
+
+    @Test
+    void doesNotAlterCustomBoardsOrStructuresThatDoNotExactlyMatch() throws Exception {
+        RegisteredBoard custom = new RegisteredBoard(
+            new BoardId(WORLD_ID, 100, 70, 100), "survival"
+        );
+        RecordingRepository customRepository = new RecordingRepository(Set.of(custom), false);
+        FakeWorld customWorld = new FakeWorld();
+        assertEquals(0, upgrader(new BoardRegistry(customRepository), customWorld).upgrade());
+        assertTrue(customWorld.placed.isEmpty());
+
+        RecordingRepository changedRepository = new RecordingRepository(
+            legacyRegistrations(), false
+        );
+        FakeWorld changedWorld = legacyWorld();
+        PhysicalBoardPlan.Placement log = plan().placements().stream()
+            .filter(placement -> "OAK_LOG".equals(placement.material())).findFirst().orElseThrow();
+        changedWorld.existing.put(log.location(), new PhysicalBoardPlan.Placement(
+            log.location(), "STONE"
+        ));
+        assertEquals(0, upgrader(new BoardRegistry(changedRepository), changedWorld).upgrade());
+        assertTrue(changedWorld.placed.isEmpty());
+    }
+
+    @Test
+    void doesNotRefreshAFullBoardWithCustomSignText() throws Exception {
+        RecordingRepository repository = new RecordingRepository(fullRegistrations(), false);
+        FakeWorld world = fullWorld(false);
+        PhysicalBoardPlan.Placement title = newSigns().stream()
+            .filter(sign -> sign.signKind() == PhysicalBoardSignKind.TITLE)
+            .findFirst().orElseThrow();
+        world.existing.put(title.location(), new PhysicalBoardPlan.Placement(
+            title.location(), title.material(), PhysicalBoardSignKind.INSTRUCTION
+        ));
+
+        assertEquals(0, upgrader(new BoardRegistry(repository), world).upgrade());
+
+        assertTrue(world.placed.isEmpty());
+        assertTrue(newSigns().stream().noneMatch(sign -> world.glowing.get(sign.location())));
+    }
+
+    @Test
+    void doesNotOverwriteAnOccupiedNewSignCell() throws Exception {
+        RecordingRepository repository = new RecordingRepository(legacyRegistrations(), false);
+        BoardRegistry registry = new BoardRegistry(repository);
+        FakeWorld world = legacyWorld();
+        BoardId title = newSigns().stream()
+            .filter(sign -> sign.signKind() == PhysicalBoardSignKind.TITLE)
+            .findFirst().orElseThrow().location();
+        world.existing.put(title, new PhysicalBoardPlan.Placement(title, "STONE"));
+
+        assertEquals(0, upgrader(registry, world).upgrade());
+
+        assertTrue(world.placed.isEmpty());
+        assertEquals(15, registry.size());
+        assertEquals(0, repository.saves);
+    }
+
+    @Test
+    void rollsBackBothCellsWhenSignConstructionFails() throws Exception {
+        RecordingRepository repository = new RecordingRepository(legacyRegistrations(), false);
+        BoardRegistry registry = new BoardRegistry(repository);
+        FakeWorld world = legacyWorld();
+        world.failPlacement = 1;
+
+        assertThrows(IOException.class, () -> upgrader(registry, world).upgrade());
+
+        assertTrue(newSigns().stream().allMatch(sign -> !world.existing.containsKey(sign.location())));
+        assertEquals(15, registry.size());
+        assertEquals(0, repository.saves);
+    }
+
+    @Test
+    void rollsBackBothReadableSignsWhenFullBoardRefreshFails() throws Exception {
+        RecordingRepository repository = new RecordingRepository(fullRegistrations(), false);
+        FakeWorld world = fullWorld(false);
+        world.failPlacement = 1;
+
+        assertThrows(IOException.class,
+            () -> upgrader(new BoardRegistry(repository), world).upgrade());
+
+        assertTrue(newSigns().stream().noneMatch(sign -> world.glowing.get(sign.location())));
+        assertEquals(0, repository.saves);
+    }
+
+    @Test
+    void rollsBackBothCellsWhenAtomicPersistenceFails() throws Exception {
+        RecordingRepository repository = new RecordingRepository(legacyRegistrations(), true);
+        BoardRegistry registry = new BoardRegistry(repository);
+        FakeWorld world = legacyWorld();
+
+        assertThrows(IOException.class, () -> upgrader(registry, world).upgrade());
+
+        assertTrue(newSigns().stream().allMatch(sign -> !world.existing.containsKey(sign.location())));
+        assertEquals(15, registry.size());
+        assertEquals(1, repository.saves);
+    }
+
+    private static PhysicalBoardUpgrader upgrader(BoardRegistry registry, FakeWorld world) {
+        return new PhysicalBoardUpgrader(
+            registry, worldId -> WORLD_ID.equals(worldId) ? world : null
+        );
+    }
+
+    private static PhysicalBoardPlan plan() {
+        return PhysicalBoardPlan.create(ANCHOR, FACING);
+    }
+
+    private static Set<RegisteredBoard> legacyRegistrations() {
+        return plan().placements().stream().filter(placement ->
+            "OAK_PLANKS".equals(placement.material())
+                || placement.signKind() == PhysicalBoardSignKind.DECORATIVE
+        ).map(placement -> new RegisteredBoard(placement.location(), "survival"))
+            .collect(Collectors.toSet());
+    }
+
+    private static Set<RegisteredBoard> fullRegistrations() {
+        return plan().interactionLocations().stream()
+            .map(location -> new RegisteredBoard(location, "survival"))
+            .collect(Collectors.toSet());
+    }
+
+    private static FakeWorld legacyWorld() {
+        FakeWorld world = new FakeWorld();
+        plan().placements().stream().filter(placement ->
+            placement.signKind() != PhysicalBoardSignKind.TITLE
+                && placement.signKind() != PhysicalBoardSignKind.INSTRUCTION
+        ).forEach(placement -> {
+            world.existing.put(placement.location(), placement);
+            world.facings.put(placement.location(), FACING);
+        });
+        return world;
+    }
+
+    private static FakeWorld fullWorld(boolean readableGlowing) {
+        FakeWorld world = new FakeWorld();
+        plan().placements().forEach(placement -> {
+            world.existing.put(placement.location(), placement);
+            if (placement.sign()) {
+                world.facings.put(placement.location(), FACING);
+                world.glowing.put(placement.location(),
+                    placement.signKind() != PhysicalBoardSignKind.DECORATIVE && readableGlowing);
+            }
+        });
+        return world;
+    }
+
+    private static java.util.List<PhysicalBoardPlan.Placement> newSigns() {
+        return plan().placements().stream().filter(placement ->
+            placement.signKind() == PhysicalBoardSignKind.TITLE
+                || placement.signKind() == PhysicalBoardSignKind.INSTRUCTION
+        ).toList();
+    }
+
+    private static final class FakeWorld implements PhysicalBoardWorld {
+        private record Snapshot(
+            PhysicalBoardPlan.Placement placement, BoardFacing facing, Boolean glowing
+        ) { }
+
+        private final Map<BoardId, PhysicalBoardPlan.Placement> existing = new HashMap<>();
+        private final Map<BoardId, BoardFacing> facings = new HashMap<>();
+        private final Map<BoardId, Boolean> glowing = new HashMap<>();
+        private final Map<BoardId, PhysicalBoardPlan.Placement> placed = new HashMap<>();
+        private int placements;
+        private int failPlacement = -1;
+
+        @Override public boolean isEmpty(BoardId location) {
+            return !existing.containsKey(location);
+        }
+
+        @Override public Object snapshot(BoardId location) {
+            return new Snapshot(
+                existing.get(location), facings.get(location), glowing.get(location)
+            );
+        }
+
+        @Override public void place(PhysicalBoardPlan.Placement placement, BoardFacing facing) {
+            if (placements++ == failPlacement) {
+                throw new IllegalStateException("simulated sign build failure");
+            }
+            existing.put(placement.location(), placement);
+            facings.put(placement.location(), facing);
+            glowing.put(placement.location(),
+                placement.signKind() != PhysicalBoardSignKind.DECORATIVE);
+            placed.put(placement.location(), placement);
+        }
+
+        @Override public boolean matches(
+            PhysicalBoardPlan.Placement placement, BoardFacing facing
+        ) {
+            return placement.equals(existing.get(placement.location()))
+                && (!placement.sign() || facing == facings.get(placement.location()));
+        }
+
+        @Override public boolean matches(
+            PhysicalBoardPlan.Placement placement, BoardFacing facing, boolean glowingText
+        ) {
+            return matches(placement, facing)
+                && glowingText == glowing.getOrDefault(placement.location(), false);
+        }
+
+        @Override public void restore(BoardId location, Object snapshot) {
+            Snapshot captured = (Snapshot) snapshot;
+            restore(existing, location, captured.placement());
+            restore(facings, location, captured.facing());
+            restore(glowing, location, captured.glowing());
+        }
+
+        private static <T> void restore(Map<BoardId, T> values, BoardId location, T value) {
+            if (value == null) {
+                values.remove(location);
+            } else {
+                values.put(location, value);
+            }
+        }
+    }
+
+    private static final class RecordingRepository implements BoardRepository {
+        private BoardState state;
+        private final boolean failSave;
+        private int saves;
+
+        private RecordingRepository(Set<RegisteredBoard> boards, boolean failSave) {
+            state = new BoardState(boards);
+            this.failSave = failSave;
+        }
+
+        @Override public BoardState load() {
+            return state;
+        }
+
+        @Override public void save(BoardState state) throws IOException {
+            saves++;
+            if (failSave) {
+                throw new IOException("disk full");
+            }
+            this.state = state;
+        }
+    }
+}

src/test/java/games/dmg/spigotquestboard/PlayerCommandSettingsTest.java

@@ -0,0 +1,52 @@
+package games.dmg.spigotquestboard;
+
+import static org.junit.jupiter.api.Assertions.assertFalse;
+import static org.junit.jupiter.api.Assertions.assertThrows;
+import static org.junit.jupiter.api.Assertions.assertTrue;
+
+import java.io.IOException;
+import java.nio.file.Path;
+import org.junit.jupiter.api.Test;
+import org.junit.jupiter.api.io.TempDir;
+
+final class PlayerCommandSettingsTest {
+    @TempDir Path temporaryDirectory;
+
+    @Test
+    void defaultsDisabledAndPersistsEnabledState() throws Exception {
+        Path path = temporaryDirectory.resolve("settings.yml");
+        PlayerCommandSettings settings = new PlayerCommandSettings(
+            new YamlPlayerCommandSettingsRepository(path)
+        );
+
+        assertFalse(settings.enabled());
+        settings.setEnabled(true);
+
+        PlayerCommandSettings reloaded = new PlayerCommandSettings(
+            new YamlPlayerCommandSettingsRepository(path)
+        );
+        assertTrue(reloaded.enabled());
+
+        reloaded.setEnabled(false);
+
+        assertFalse(new PlayerCommandSettings(
+            new YamlPlayerCommandSettingsRepository(path)
+        ).enabled());
+    }
+
+    @Test
+    void persistenceFailureLeavesPriorState() throws Exception {
+        PlayerCommandSettings settings = new PlayerCommandSettings(
+            new PlayerCommandSettingsRepository() {
+                @Override public boolean loadEnabled() { return false; }
+                @Override public void saveEnabled(boolean enabled) throws IOException {
+                    throw new IOException("disk full");
+                }
+            }
+        );
+
+        assertThrows(IOException.class, () -> settings.setEnabled(true));
+
+        assertFalse(settings.enabled());
+    }
+}

src/test/java/games/dmg/spigotquestboard/PluginCommandWiringTest.java

@@ -0,0 +1,136 @@
+package games.dmg.spigotquestboard;
+
+import static org.junit.jupiter.api.Assertions.assertEquals;
+import static org.junit.jupiter.api.Assertions.assertTrue;
+import static org.mockito.Mockito.mock;
+import static org.mockito.Mockito.verify;
+import static org.mockito.Mockito.when;
+
+import java.time.Clock;
+import java.util.List;
+import java.util.Set;
+import java.util.UUID;
+import java.util.concurrent.atomic.AtomicInteger;
+import org.bukkit.Location;
+import org.bukkit.World;
+import org.bukkit.command.Command;
+import org.bukkit.command.CommandSender;
+import org.bukkit.entity.Player;
+import org.junit.jupiter.api.Test;
+
+final class PluginCommandWiringTest {
+    @Test
+    void startupPhysicalBoardUpgradeDelegatesToLoadedWorlds() throws Exception {
+        UUID worldId = UUID.randomUUID();
+        PhysicalBoardPlan plan = PhysicalBoardPlan.create(
+            new BoardId(worldId, 1, 64, 1), BoardFacing.NORTH
+        );
+        Set<RegisteredBoard> legacy = plan.placements().stream()
+            .filter(placement -> "OAK_PLANKS".equals(placement.material())
+                || placement.signKind() == PhysicalBoardSignKind.DECORATIVE)
+            .map(placement -> new RegisteredBoard(placement.location(), "survival"))
+            .collect(java.util.stream.Collectors.toSet());
+        BoardRegistry registry = new BoardRegistry(new BoardRepository() {
+            @Override public BoardState load() { return new BoardState(legacy); }
+            @Override public void save(BoardState state) { }
+        });
+        AtomicInteger worldLookups = new AtomicInteger();
+
+        int upgraded = SpigotQuestBoardPlugin.upgradePhysicalBoards(registry, id -> {
+            assertEquals(worldId, id);
+            worldLookups.incrementAndGet();
+            return null;
+        });
+
+        assertEquals(0, upgraded);
+        assertTrue(worldLookups.get() > 0);
+    }
+
+    @Test
+    void playerCommandUsesBoardRegistryForNearbyCreation() throws Exception {
+        UUID worldId = UUID.randomUUID();
+        BoardId boardId = new BoardId(worldId, 10, 64, 20);
+        BoardRegistry boards = new BoardRegistry(new BoardRepository() {
+            @Override public BoardState load() {
+                return new BoardState(Set.of(new RegisteredBoard(boardId, "survival")));
+            }
+            @Override public void save(BoardState state) { }
+        });
+        PlayerCommandSettings settings = new PlayerCommandSettings(
+            new PlayerCommandSettingsRepository() {
+                @Override public boolean loadEnabled() { return false; }
+                @Override public void saveEnabled(boolean enabled) { }
+            }
+        );
+        QuestCreationGateway creator = mock(QuestCreationGateway.class);
+        Quest created = mock(Quest.class);
+        when(created.id()).thenReturn(UUID.randomUUID());
+        when(creator.create(
+            org.mockito.ArgumentMatchers.any(),
+            org.mockito.ArgumentMatchers.anyString(),
+            org.mockito.ArgumentMatchers.anyInt(),
+            org.mockito.ArgumentMatchers.any()
+        )).thenReturn(created);
+        SpigotQuestBoardPlugin.CommandHandlers handlers =
+            SpigotQuestBoardPlugin.commandHandlers(
+                boards, settings, creator, mock(QuestBrowser.class), null, null, null,
+                Clock.systemUTC()
+            );
+        World world = mock(World.class);
+        when(world.getUID()).thenReturn(worldId);
+        Player player = mock(Player.class);
+        when(player.getWorld()).thenReturn(world);
+        when(player.getLocation()).thenReturn(new Location(world, 13, 68, 20));
+
+        assertTrue(handlers.quests().onCommand(
+            player, mock(Command.class), "quests", new String[] {"create", "stone", "1"}
+        ));
+
+        verify(creator).create(
+            org.mockito.ArgumentMatchers.eq(player),
+            org.mockito.ArgumentMatchers.eq("stone"),
+            org.mockito.ArgumentMatchers.eq(1),
+            org.mockito.ArgumentMatchers.any()
+        );
+    }
+
+    @Test
+    void adminAndPlayerCommandsShareThePersistedSetting() throws Exception {
+        PlayerCommandSettings settings = new PlayerCommandSettings(
+            new PlayerCommandSettingsRepository() {
+                private boolean enabled;
+                @Override public boolean loadEnabled() { return enabled; }
+                @Override public void saveEnabled(boolean enabled) { this.enabled = enabled; }
+            }
+        );
+        BoardRepository boards = new BoardRepository() {
+            @Override public BoardState load() { return new BoardState(Set.of()); }
+            @Override public void save(BoardState state) { }
+        };
+        QuestBrowser browser = mock(QuestBrowser.class);
+        when(browser.activeQuests(org.mockito.ArgumentMatchers.any())).thenReturn(List.of());
+        SpigotQuestBoardPlugin.CommandHandlers handlers =
+            SpigotQuestBoardPlugin.commandHandlers(
+                new BoardRegistry(boards), settings, mock(QuestCreationGateway.class), browser,
+                null, null, null, Clock.systemUTC()
+            );
+        Player player = mock(Player.class);
+        CommandSender admin = mock(CommandSender.class);
+        when(admin.hasPermission("spigotquestboard.admin")).thenReturn(true);
+        Command command = mock(Command.class);
+
+        assertTrue(handlers.quests().onCommand(
+            player, command, "quests", new String[] {"list"}
+        ));
+        verify(player).sendMessage(
+            "Player quest commands are disabled. Use a physical quest board instead."
+        );
+
+        handlers.admin().onCommand(
+            admin, command, "questadmin", new String[] {"commands", "enable"}
+        );
+        handlers.quests().onCommand(player, command, "quests", new String[] {"list"});
+
+        verify(browser).activeQuests(org.mockito.ArgumentMatchers.any());
+    }
+}

src/test/java/games/dmg/spigotquestboard/QuestAdminCommandTest.java

@@ -1,5 +1,6 @@
 package games.dmg.spigotquestboard;
 
+import static org.junit.jupiter.api.Assertions.assertEquals;
 import static org.junit.jupiter.api.Assertions.assertFalse;
 import static org.junit.jupiter.api.Assertions.assertTrue;
 import static org.mockito.Mockito.mock;
@@ -7,9 +8,13 @@ import static org.mockito.Mockito.never;
 import static org.mockito.Mockito.verify;
 import static org.mockito.Mockito.when;
 
+import java.io.IOException;
+import java.util.List;
 import java.util.Set;
 import java.util.UUID;
+import java.util.concurrent.atomic.AtomicInteger;
 import org.bukkit.World;
+import org.bukkit.block.BlockFace;
 import org.bukkit.block.Block;
 import org.bukkit.command.Command;
 import org.bukkit.command.CommandSender;
@@ -20,7 +25,10 @@ final class QuestAdminCommandTest {
     @Test
     void unauthorizedSenderCannotCreateBoard() throws Exception {
         MemoryBoardRepository repository = new MemoryBoardRepository();
-        QuestAdminCommand executor = new QuestAdminCommand(new BoardRegistry(repository));
+        QuestAdminCommand executor = new QuestAdminCommand(
+            new BoardRegistry(repository),
+            new PlayerCommandSettings(new MemoryPlayerCommandSettingsRepository())
+        );
         Player player = mock(Player.class);
         when(player.hasPermission("spigotquestboard.admin")).thenReturn(false);
 
@@ -30,10 +38,114 @@ final class QuestAdminCommandTest {
         assertTrue(repository.state.boards().isEmpty());
     }
 
+    @Test
+    void authorizedSenderCanEnableAndDisablePlayerCommands() throws Exception {
+        MemoryPlayerCommandSettingsRepository settingsRepository =
+            new MemoryPlayerCommandSettingsRepository();
+        PlayerCommandSettings settings = new PlayerCommandSettings(settingsRepository);
+        QuestAdminCommand executor = new QuestAdminCommand(
+            new BoardRegistry(new MemoryBoardRepository()), settings
+        );
+        CommandSender sender = mock(CommandSender.class);
+        when(sender.hasPermission("spigotquestboard.admin")).thenReturn(true);
+
+        assertTrue(executor.onCommand(
+            sender, mock(Command.class), "questadmin", new String[] {"commands", "enable"}
+        ));
+        assertTrue(settings.enabled());
+        assertTrue(executor.onCommand(
+            sender, mock(Command.class), "questadmin", new String[] {"commands", "disable"}
+        ));
+
+        assertFalse(settings.enabled());
+        verify(sender).sendMessage("Player quest commands enabled.");
+        verify(sender).sendMessage("Player quest commands disabled.");
+    }
+
+    @Test
+    void unauthorizedSenderCannotChangePlayerCommands() throws Exception {
+        MemoryPlayerCommandSettingsRepository repository =
+            new MemoryPlayerCommandSettingsRepository();
+        PlayerCommandSettings settings = new PlayerCommandSettings(repository);
+        QuestAdminCommand executor = new QuestAdminCommand(
+            new BoardRegistry(new MemoryBoardRepository()), settings
+        );
+        CommandSender sender = mock(CommandSender.class);
+        when(sender.hasPermission("spigotquestboard.admin")).thenReturn(false);
+
+        executor.onCommand(
+            sender, mock(Command.class), "questadmin", new String[] {"commands", "enable"}
+        );
+
+        assertFalse(settings.enabled());
+        assertEquals(0, repository.saves);
+    }
+
+    @Test
+    void settingsPersistenceFailureIsReportedAndLeavesPriorState() throws Exception {
+        PlayerCommandSettings settings = new PlayerCommandSettings(
+            new PlayerCommandSettingsRepository() {
+                @Override public boolean loadEnabled() { return false; }
+                @Override public void saveEnabled(boolean enabled) throws IOException {
+                    throw new IOException("disk full");
+                }
+            }
+        );
+        QuestAdminCommand executor = new QuestAdminCommand(
+            new BoardRegistry(new MemoryBoardRepository()), settings
+        );
+        CommandSender sender = mock(CommandSender.class);
+        when(sender.hasPermission("spigotquestboard.admin")).thenReturn(true);
+
+        executor.onCommand(
+            sender, mock(Command.class), "questadmin", new String[] {"commands", "enable"}
+        );
+
+        assertFalse(settings.enabled());
+        verify(sender).sendMessage(
+            "Player command setting could not be saved. Player quest commands remain disabled."
+        );
+    }
+
+    @Test
+    void autocompleteIsPermissionAwareAndContextual() throws Exception {
+        QuestAdminCommand executor = new QuestAdminCommand(
+            new BoardRegistry(new MemoryBoardRepository()),
+            new PlayerCommandSettings(new MemoryPlayerCommandSettingsRepository())
+        );
+        CommandSender authorized = mock(CommandSender.class);
+        when(authorized.hasPermission("spigotquestboard.admin")).thenReturn(true);
+        CommandSender unauthorized = mock(CommandSender.class);
+        when(unauthorized.hasPermission("spigotquestboard.admin")).thenReturn(false);
+        Command command = mock(Command.class);
+
+        assertEquals(List.of("commands"), executor.onTabComplete(
+            authorized, command, "questadmin", new String[] {"com"}
+        ));
+        assertEquals(List.of("enable"), executor.onTabComplete(
+            authorized, command, "questadmin", new String[] {"commands", "en"}
+        ));
+        assertEquals(List.of("disable"), executor.onTabComplete(
+            authorized, command, "questadmin", new String[] {"commands", "di"}
+        ));
+        assertEquals(List.of("physical"), executor.onTabComplete(
+            authorized, command, "questadmin", new String[] {"createboard", ""}
+        ));
+        assertEquals(List.of("physical"), executor.onTabComplete(
+            authorized, command, "questadmin", new String[] {"createboard", "phy"}
+        ));
+        assertTrue(executor.onTabComplete(
+            unauthorized, command, "questadmin", new String[] {""}
+        ).isEmpty());
+    }
+
     @Test
     void registersTargetedPhysicalBlock() throws Exception {
         MemoryBoardRepository repository = new MemoryBoardRepository();
-        QuestAdminCommand executor = new QuestAdminCommand(new BoardRegistry(repository));
+        QuestAdminCommand executor = new QuestAdminCommand(
+            new BoardRegistry(repository),
+            new PlayerCommandSettings(new MemoryPlayerCommandSettingsRepository())
+        );
         Player player = mock(Player.class);
         Block block = mock(Block.class);
         World world = mock(World.class);
@@ -54,10 +166,102 @@ final class QuestAdminCommandTest {
         )));
     }
 
+    @Test
+    void physicalArgumentBuildsAndRegistersAllInteractionLocations() throws Exception {
+        MemoryBoardRepository repository = new MemoryBoardRepository();
+        BoardRegistry registry = new BoardRegistry(repository);
+        AtomicInteger placements = new AtomicInteger();
+        PhysicalBoardWorld worldAdapter = new PhysicalBoardWorld() {
+            @Override public boolean isEmpty(BoardId location) { return true; }
+            @Override public Object snapshot(BoardId location) { return "AIR"; }
+            @Override public void place(
+                PhysicalBoardPlan.Placement placement, BoardFacing facing
+            ) {
+                assertEquals(BoardFacing.SOUTH, facing);
+                placements.incrementAndGet();
+            }
+            @Override public void restore(BoardId location, Object snapshot) { }
+        };
+        QuestAdminCommand executor = new QuestAdminCommand(
+            registry,
+            new PlayerCommandSettings(new MemoryPlayerCommandSettingsRepository()),
+            new PhysicalBoardCreator(registry, ignored -> worldAdapter)
+        );
+        Player player = mock(Player.class);
+        Block anchor = mock(Block.class);
+        World world = mock(World.class);
+        UUID worldId = UUID.randomUUID();
+        when(player.hasPermission("spigotquestboard.admin")).thenReturn(true);
+        when(player.getTargetBlockExact(5)).thenReturn(anchor);
+        when(player.getFacing()).thenReturn(BlockFace.NORTH);
+        when(anchor.getWorld()).thenReturn(world);
+        when(world.getUID()).thenReturn(worldId);
+        when(world.getName()).thenReturn("world");
+        when(anchor.getX()).thenReturn(3);
+        when(anchor.getY()).thenReturn(70);
+        when(anchor.getZ()).thenReturn(4);
+
+        assertTrue(executor.onCommand(
+            player, mock(Command.class), "questadmin",
+            new String[] {"createboard", "physical"}
+        ));
+
+        assertEquals(25, placements.get());
+        assertEquals(17, repository.state.boards().size());
+        verify(player).sendMessage("Physical quest board created.");
+    }
+
+    @Test
+    void physicalBoardObstructionIsReportedWithoutRegistration() throws Exception {
+        MemoryBoardRepository repository = new MemoryBoardRepository();
+        BoardRegistry registry = new BoardRegistry(repository);
+        PhysicalBoardWorld obstructedWorld = new PhysicalBoardWorld() {
+            @Override public boolean isEmpty(BoardId location) { return false; }
+            @Override public Object snapshot(BoardId location) {
+                throw new AssertionError("obstructed generation must not snapshot");
+            }
+            @Override public void place(
+                PhysicalBoardPlan.Placement placement, BoardFacing facing
+            ) {
+                throw new AssertionError("obstructed generation must not place");
+            }
+            @Override public void restore(BoardId location, Object snapshot) {
+                throw new AssertionError("obstructed generation must not restore");
+            }
+        };
+        QuestAdminCommand executor = new QuestAdminCommand(
+            registry,
+            new PlayerCommandSettings(new MemoryPlayerCommandSettingsRepository()),
+            new PhysicalBoardCreator(registry, ignored -> obstructedWorld)
+        );
+        Player player = mock(Player.class);
+        Block anchor = mock(Block.class);
+        World world = mock(World.class);
+        when(player.hasPermission("spigotquestboard.admin")).thenReturn(true);
+        when(player.getTargetBlockExact(5)).thenReturn(anchor);
+        when(player.getFacing()).thenReturn(BlockFace.SOUTH);
+        when(anchor.getWorld()).thenReturn(world);
+        when(world.getUID()).thenReturn(UUID.randomUUID());
+        when(world.getName()).thenReturn("world");
+
+        executor.onCommand(
+            player, mock(Command.class), "questadmin",
+            new String[] {"createboard", "physical"}
+        );
+
+        assertTrue(repository.state.boards().isEmpty());
+        verify(player).sendMessage(
+            "The physical quest board needs 23 empty placement blocks."
+        );
+    }
+
     @Test
     void consoleAndMissingTargetDoNotChangeState() throws Exception {
         MemoryBoardRepository repository = new MemoryBoardRepository();
-        QuestAdminCommand executor = new QuestAdminCommand(new BoardRegistry(repository));
+        QuestAdminCommand executor = new QuestAdminCommand(
+            new BoardRegistry(repository),
+            new PlayerCommandSettings(new MemoryPlayerCommandSettingsRepository())
+        );
         CommandSender console = mock(CommandSender.class);
         when(console.hasPermission("spigotquestboard.admin")).thenReturn(true);
         assertTrue(executor.onCommand(console, mock(Command.class), "questadmin", new String[] {"createboard"}));
@@ -70,6 +274,18 @@ final class QuestAdminCommandTest {
         assertTrue(repository.state.boards().isEmpty());
     }
 
+    private static final class MemoryPlayerCommandSettingsRepository
+        implements PlayerCommandSettingsRepository {
+        private boolean enabled;
+        private int saves;
+
+        @Override public boolean loadEnabled() { return enabled; }
+        @Override public void saveEnabled(boolean enabled) {
+            this.enabled = enabled;
+            saves++;
+        }
+    }
+
     private static final class MemoryBoardRepository implements BoardRepository {
         private BoardState state = new BoardState(Set.of());
         @Override public BoardState load() { return state; }

src/test/java/games/dmg/spigotquestboard/QuestBoardDialogUiTest.java

@@ -1,8 +1,11 @@
 package games.dmg.spigotquestboard;
 
 import static org.junit.jupiter.api.Assertions.assertEquals;
+import static org.junit.jupiter.api.Assertions.assertFalse;
+import static org.junit.jupiter.api.Assertions.assertTrue;
 import static org.mockito.Mockito.mock;
 import static org.mockito.Mockito.verify;
+import static org.mockito.Mockito.when;
 
 import java.io.IOException;
 import java.time.Clock;
@@ -16,6 +19,180 @@ import org.junit.jupiter.api.Test;
 final class QuestBoardDialogUiTest {
     private static final Instant NOW = Instant.parse("2026-09-05T03:00:00Z");
 
+    @Test
+    void dashboardUsesCompactDedicatedNavigableScreens() {
+        RecordingCreator creator = new RecordingCreator(false);
+        QuestBoardDialogUi ui = new QuestBoardDialogUi(
+            creator, now -> List.of(creator.quest(NOW)), Clock.fixed(NOW, ZoneOffset.UTC)
+        );
+
+        QuestBoardDialogSpec specification = ui.specification(mock(Player.class));
+
+        assertEquals(420, specification.maximumBodyWidth());
+        assertEquals(List.of("Browse quests", "Create quest", "Pending claims"),
+            specification.dashboardActions());
+        assertEquals(1, specification.questEntries().size());
+        org.junit.jupiter.api.Assertions.assertTrue(
+            specification.questEntries().getFirst().hasBackAction()
+        );
+    }
+
+    @Test
+    void dedicatedScreensKeepContentSeparateAndProvideBackNavigation() {
+        RecordingCreator creator = new RecordingCreator(false);
+        QuestBoardDialogUi ui = new QuestBoardDialogUi(
+            creator, now -> List.of(creator.quest(NOW)), null, null, player ->
+                new ClaimCollectionResult(0, 0), Clock.fixed(NOW, ZoneOffset.UTC)
+        );
+
+        QuestBoardDialogSpec specification = ui.specification(mock(Player.class));
+
+        assertEquals("Choose what you want to do.", specification.dashboard().message());
+        assertTrue(specification.browse().message().contains("Select a quest"));
+        assertTrue(specification.create().message().contains("reward in your main hand"));
+        assertEquals("No pending claims.", specification.claims().message());
+        assertFalse(specification.dashboard().hasBackAction());
+        assertTrue(specification.browse().hasBackAction());
+        assertTrue(specification.create().hasBackAction());
+        assertTrue(specification.claims().hasBackAction());
+        assertTrue(specification.questEntries().stream().allMatch(
+            QuestBoardDialogSpec.QuestEntry::hasBackAction
+        ));
+    }
+
+    @Test
+    void questDetailsShowRequiredContentAndRouteAvailableActions() {
+        RecordingCreator creator = new RecordingCreator(false);
+        Quest quest = creator.quest(NOW);
+        Player issuer = mock(Player.class);
+        when(issuer.getUniqueId()).thenReturn(quest.issuerId());
+        QuestBoardDialogUi ui = new QuestBoardDialogUi(
+            creator, now -> List.of(quest), new RecordingCompleter(), new RecordingCanceller(),
+            null, Clock.fixed(NOW, ZoneOffset.UTC)
+        );
+
+        QuestBoardDialogSpec specification = ui.specification(issuer);
+        QuestBoardDialogSpec.QuestEntry entry = specification.questEntries().getFirst();
+
+        assertTrue(entry.message().contains("64 × STONE"));
+        assertTrue(entry.message().contains("Reward: 1 × DIAMOND"));
+        assertTrue(entry.message().contains("Issuer: Issuer"));
+        assertTrue(entry.message().contains("Time remaining: 7d"));
+        assertEquals(
+            List.of(QuestBoardDialogSpec.Route.COMPLETE, QuestBoardDialogSpec.Route.CANCEL),
+            entry.actions().stream().map(QuestBoardDialogSpec.Action::route).toList()
+        );
+        assertTrue(entry.actions().stream().allMatch(
+            action -> quest.id().toString().equals(action.questId())
+        ));
+    }
+
+    @Test
+    void dashboardCreationAndClaimsDeclareTheirActionRoutesAndInputs() {
+        RecordingCreator creator = new RecordingCreator(false);
+        QuestBoardDialogUi ui = new QuestBoardDialogUi(
+            creator, now -> List.of(), null, null, player ->
+                new ClaimCollectionResult(0, 0), Clock.fixed(NOW, ZoneOffset.UTC)
+        );
+
+        QuestBoardDialogSpec specification = ui.specification(mock(Player.class));
+
+        assertEquals(
+            List.of(
+                QuestBoardDialogSpec.Route.OPEN_BROWSE,
+                QuestBoardDialogSpec.Route.OPEN_CREATE,
+                QuestBoardDialogSpec.Route.OPEN_CLAIMS
+            ),
+            specification.dashboard().actions().stream()
+                .map(QuestBoardDialogSpec.Action::route)
+                .toList()
+        );
+        assertEquals(List.of("requested_material", "requested_quantity"),
+            specification.create().inputs().stream()
+                .map(QuestBoardDialogSpec.Input::key)
+                .toList());
+        assertEquals(QuestBoardDialogSpec.Route.SUBMIT_CREATE,
+            specification.create().actions().getFirst().route());
+        assertEquals(QuestBoardDialogSpec.Route.COLLECT,
+            specification.claims().actions().getFirst().route());
+    }
+
+    @Test
+    void largeQuestCollectionsRemainIndividualNavigableEntries() {
+        RecordingCreator creator = new RecordingCreator(false);
+        List<Quest> quests = java.util.stream.IntStream.range(0, 250)
+            .mapToObj(index -> new Quest(
+                new UUID(0, index + 100L), new UUID(0, index + 1L), "Issuer " + index,
+                "STONE", index + 1, List.of(new EscrowItem("DIAMOND", 1, null)),
+                NOW, NOW.plusSeconds(604800)
+            ))
+            .toList();
+        QuestBoardDialogUi ui = new QuestBoardDialogUi(
+            creator, now -> quests, Clock.fixed(NOW, ZoneOffset.UTC)
+        );
+
+        QuestBoardDialogSpec specification = ui.specification(mock(Player.class));
+
+        assertEquals(250, specification.questEntries().size());
+        assertTrue(specification.questEntries().stream().allMatch(
+            QuestBoardDialogSpec.QuestEntry::hasBackAction
+        ));
+        assertFalse(specification.browse().message().contains(quests.getLast().id().toString()));
+    }
+
+    @Test
+    void nonIssuersCannotReceiveCancellationRoutes() {
+        RecordingCreator creator = new RecordingCreator(false);
+        Player player = mock(Player.class);
+        when(player.getUniqueId()).thenReturn(UUID.randomUUID());
+        QuestBoardDialogUi ui = new QuestBoardDialogUi(
+            creator, now -> List.of(creator.quest(NOW)), new RecordingCompleter(),
+            new RecordingCanceller(), Clock.fixed(NOW, ZoneOffset.UTC)
+        );
+
+        QuestBoardDialogSpec.QuestEntry entry = ui.specification(player)
+            .questEntries().getFirst();
+
+        assertEquals(List.of(QuestBoardDialogSpec.Route.COMPLETE),
+            entry.actions().stream().map(QuestBoardDialogSpec.Action::route).toList());
+    }
+
+    @Test
+    void disabledPlayerCommandsDoNotGateBoardUiGateways() throws Exception {
+        PlayerCommandSettings settings = new PlayerCommandSettings(
+            new PlayerCommandSettingsRepository() {
+                @Override public boolean loadEnabled() { return false; }
+                @Override public void saveEnabled(boolean enabled) { }
+            }
+        );
+        RecordingCreator creator = new RecordingCreator(false);
+        RecordingCompleter completer = new RecordingCompleter();
+        RecordingCanceller canceller = new RecordingCanceller();
+        java.util.concurrent.atomic.AtomicReference<Player> claimantPlayer =
+            new java.util.concurrent.atomic.AtomicReference<>();
+        QuestClaimGateway claimant = player -> {
+            claimantPlayer.set(player);
+            return new ClaimCollectionResult(0, 0);
+        };
+        QuestBoardDialogUi ui = new QuestBoardDialogUi(
+            creator, now -> List.of(creator.quest(NOW)), completer, canceller, claimant,
+            Clock.fixed(NOW, ZoneOffset.UTC)
+        );
+        Player player = mock(Player.class);
+
+        ui.listingText();
+        ui.submit(player, "stone", "1");
+        ui.submitCompletion(player, "complete-id");
+        ui.submitCancellation(player, "cancel-id");
+        ui.submitClaim(player);
+
+        org.junit.jupiter.api.Assertions.assertFalse(settings.enabled());
+        assertEquals("stone", creator.material);
+        assertEquals(player, completer.player);
+        assertEquals(player, canceller.player);
+        assertEquals(player, claimantPlayer.get());
+    }
+
     @Test
     void dialogSubmissionUsesEquivalentCreationFlow() {
         RecordingCreator creator = new RecordingCreator(false);
@@ -35,6 +212,119 @@ final class QuestBoardDialogUiTest {
         );
     }
 
+    @Test
+    void completionActionUsesEquivalentCompletionFlow() {
+        RecordingCreator creator = new RecordingCreator(false);
+        RecordingCompleter completer = new RecordingCompleter();
+        QuestBoardDialogUi ui = new QuestBoardDialogUi(
+            creator, now -> List.of(), completer, Clock.fixed(NOW, ZoneOffset.UTC)
+        );
+        Player player = mock(Player.class);
+        String id = UUID.randomUUID().toString();
+
+        ui.submitCompletion(player, id);
+
+        assertEquals(player, completer.player);
+        assertEquals(id, completer.questId);
+        assertEquals(NOW, completer.completedAt);
+    }
+
+    @Test
+    void claimActionUsesEquivalentCollectionFlowAtABoard() {
+        RecordingCreator creator = new RecordingCreator(false);
+        java.util.concurrent.atomic.AtomicReference<Player> claimantPlayer =
+            new java.util.concurrent.atomic.AtomicReference<>();
+        QuestClaimGateway claimant = player -> {
+            claimantPlayer.set(player);
+            return new ClaimCollectionResult(1, 0);
+        };
+        QuestBoardDialogUi ui = new QuestBoardDialogUi(
+            creator, now -> List.of(), null, null, claimant,
+            Clock.fixed(NOW, ZoneOffset.UTC)
+        );
+        Player player = mock(Player.class);
+
+        ui.submitClaim(player);
+
+        assertEquals(player, claimantPlayer.get());
+    }
+
+    @Test
+    void cancellationActionUsesEquivalentCancellationFlow() {
+        RecordingCreator creator = new RecordingCreator(false);
+        RecordingCanceller canceller = new RecordingCanceller();
+        QuestBoardDialogUi ui = new QuestBoardDialogUi(
+            creator, now -> List.of(), null, canceller, Clock.fixed(NOW, ZoneOffset.UTC)
+        );
+        Player player = mock(Player.class);
+        String id = UUID.randomUUID().toString();
+
+        ui.submitCancellation(player, id);
+
+        assertEquals(player, canceller.player);
+        assertEquals(id, canceller.questId);
+        assertEquals(NOW, canceller.cancelledAt);
+    }
+
+    @Test
+    void boardListingDistinguishesDeliveredItemsFromReturnedRewards() {
+        RecordingCreator creator = new RecordingCreator(false);
+        Player player = mock(Player.class);
+        UUID owner = UUID.randomUUID();
+        org.mockito.Mockito.when(player.getUniqueId()).thenReturn(owner);
+        QuestClaimGateway claimant = new QuestClaimGateway() {
+            @Override
+            public ClaimCollectionResult collect(Player ignored) {
+                return new ClaimCollectionResult(0, 0);
+            }
+
+            @Override
+            public List<QuestClaim> pendingClaims(Player ignored) {
+                return List.of(
+                    new QuestClaim(
+                        UUID.randomUUID(), UUID.randomUUID(), owner,
+                        List.of(new EscrowItem("STONE", 2, null)), NOW,
+                        QuestClaimSource.COMPLETION
+                    ),
+                    new QuestClaim(
+                        UUID.randomUUID(), UUID.randomUUID(), owner,
+                        List.of(new EscrowItem("DIAMOND", 1, null)), NOW,
+                        QuestClaimSource.EXPIRATION
+                    )
+                );
+            }
+        };
+        QuestBoardDialogUi ui = new QuestBoardDialogUi(
+            creator, now -> List.of(), null, null, claimant,
+            Clock.fixed(NOW, ZoneOffset.UTC)
+        );
+
+        String listing = ui.claimListingText(player);
+
+        org.junit.jupiter.api.Assertions.assertTrue(listing.contains("DELIVERED ITEMS — 2 STONE"));
+        org.junit.jupiter.api.Assertions.assertTrue(
+            listing.contains("RETURNED REWARD (EXPIRATION) — 1 DIAMOND")
+        );
+    }
+
+    @Test
+    void boardOnlyOffersCancellationActionsForPlayersOwnedActiveQuests() {
+        RecordingCreator creator = new RecordingCreator(false);
+        Quest owned = creator.quest(NOW);
+        Quest other = new Quest(
+            UUID.randomUUID(), UUID.randomUUID(), "Other", "DIRT", 1,
+            List.of(new EscrowItem("COAL", 1, null)), NOW, NOW.plusSeconds(604800)
+        );
+        QuestBoardDialogUi ui = new QuestBoardDialogUi(
+            creator, now -> List.of(owned, other), null, new RecordingCanceller(),
+            Clock.fixed(NOW, ZoneOffset.UTC)
+        );
+        Player issuer = mock(Player.class);
+        org.mockito.Mockito.when(issuer.getUniqueId()).thenReturn(owned.issuerId());
+
+        assertEquals(List.of(owned.id().toString()), ui.cancellableQuestIds(issuer));
+    }
+
     @Test
     void everyOpeningBuildsAListingFromTheCurrentActiveQuests() {
         RecordingCreator creator = new RecordingCreator(false);
@@ -60,6 +350,34 @@ final class QuestBoardDialogUiTest {
         );
     }
 
+    private static final class RecordingCanceller implements QuestCancellationGateway {
+        private Player player;
+        private String questId;
+        private Instant cancelledAt;
+
+        @Override
+        public QuestClaim cancel(Player cancellingPlayer, String id, Instant instant) {
+            player = cancellingPlayer;
+            questId = id;
+            cancelledAt = instant;
+            return null;
+        }
+    }
+
+    private static final class RecordingCompleter implements QuestCompletionGateway {
+        private Player player;
+        private String questId;
+        private Instant completedAt;
+
+        @Override
+        public QuestCompletion complete(Player completingPlayer, String id, Instant instant) {
+            player = completingPlayer;
+            questId = id;
+            completedAt = instant;
+            return null;
+        }
+    }
+
     private static final class RecordingCreator implements QuestCreationGateway {
         private final boolean fail;
         private String material;
@@ -94,7 +412,7 @@ final class QuestBoardDialogUiTest {
         }
 
         @Override
-        public List<String> suggestBlockMaterials(String prefix) {
+        public List<String> suggestItemMaterials(String prefix) {
             return List.of();
         }
     }

src/test/java/games/dmg/spigotquestboard/QuestCancellationControllerTest.java

@@ -0,0 +1,58 @@
+package games.dmg.spigotquestboard;
+
+import static org.junit.jupiter.api.Assertions.assertEquals;
+import static org.junit.jupiter.api.Assertions.assertThrows;
+import static org.mockito.ArgumentMatchers.contains;
+import static org.mockito.Mockito.mock;
+import static org.mockito.Mockito.verify;
+import static org.mockito.Mockito.when;
+
+import java.io.IOException;
+import java.time.Instant;
+import java.util.List;
+import java.util.UUID;
+import org.bukkit.entity.Player;
+import org.junit.jupiter.api.Test;
+
+final class QuestCancellationControllerTest {
+    @Test
+    void cancelsAsPlayerIdentityAndCreatesClaimWithoutInventorySettlement() throws Exception {
+        Repository repository = new Repository();
+        QuestService service = new QuestService(repository);
+        UUID issuer = UUID.randomUUID();
+        Quest quest = service.create(
+            issuer, "Issuer", "STONE", 1,
+            List.of(new EscrowItem("DIAMOND", 2, "exact-data")), Instant.EPOCH
+        );
+        Player player = mock(Player.class);
+        when(player.getUniqueId()).thenReturn(issuer);
+
+        QuestClaim claim = new QuestCancellationController(service).cancel(
+            player, quest.id().toString(), Instant.EPOCH.plusSeconds(1)
+        );
+
+        assertEquals(quest.reward(), claim.items());
+        assertEquals(List.of(claim), service.state().claims().get(issuer));
+        verify(player).sendMessage(contains("claim"));
+    }
+
+    @Test
+    void rejectsMalformedQuestIdentifier() throws Exception {
+        QuestCancellationController controller = new QuestCancellationController(
+            new QuestService(new Repository())
+        );
+
+        IllegalArgumentException exception = assertThrows(
+            IllegalArgumentException.class,
+            () -> controller.cancel(mock(Player.class), "not-a-uuid", Instant.EPOCH)
+        );
+
+        assertEquals("Quest identifier must be a valid UUID.", exception.getMessage());
+    }
+
+    private static final class Repository implements QuestRepository {
+        private QuestState state = QuestState.empty();
+        @Override public QuestState load() { return state; }
+        @Override public void save(QuestState candidate) throws IOException { state = candidate; }
+    }
+}

src/test/java/games/dmg/spigotquestboard/QuestCancellationServiceTest.java

@@ -0,0 +1,159 @@
+package games.dmg.spigotquestboard;
+
+import static org.junit.jupiter.api.Assertions.assertEquals;
+import static org.junit.jupiter.api.Assertions.assertThrows;
+import static org.junit.jupiter.api.Assertions.assertTrue;
+
+import java.io.IOException;
+import java.time.Instant;
+import java.util.ArrayList;
+import java.util.List;
+import java.util.UUID;
+import java.util.concurrent.CountDownLatch;
+import java.util.concurrent.ExecutorService;
+import java.util.concurrent.Executors;
+import java.util.concurrent.Future;
+import org.junit.jupiter.api.Test;
+
+final class QuestCancellationServiceTest {
+    @Test
+    void onlyIssuerCanCancelAndExactRewardBecomesClaim() throws Exception {
+        Repository repository = new Repository();
+        QuestService service = new QuestService(repository);
+        UUID issuer = UUID.randomUUID();
+        EscrowItem reward = new EscrowItem("DIAMOND", 3, "exact-item-data");
+        Quest quest = service.create(
+            issuer, "Issuer", "STONE", 64, List.of(reward), Instant.EPOCH
+        );
+
+        assertThrows(IllegalArgumentException.class, () -> service.cancel(
+            quest.id(), UUID.randomUUID(), Instant.EPOCH.plusSeconds(1)
+        ));
+        QuestClaim claim = service.cancel(
+            quest.id(), issuer, Instant.EPOCH.plusSeconds(1)
+        );
+
+        assertEquals(QuestStatus.CANCELLED, service.state().quests().get(quest.id()).status());
+        assertEquals(List.of(reward), claim.items());
+        assertEquals(List.of(claim), service.state().claims().get(issuer));
+        assertTrue(service.activeQuests(Instant.EPOCH.plusSeconds(1)).isEmpty());
+    }
+
+    @Test
+    void completedCancelledAndExpiredQuestsCannotBeCancelled() throws Exception {
+        Repository repository = new Repository();
+        QuestService service = new QuestService(repository);
+        UUID issuer = UUID.randomUUID();
+        Quest completed = quest(service, issuer);
+        service.complete(
+            completed.id(), new EscrowItem("STONE", 1, null), Instant.EPOCH.plusSeconds(1)
+        );
+        Quest cancelled = quest(service, issuer);
+        service.cancel(cancelled.id(), issuer, Instant.EPOCH.plusSeconds(1));
+        Quest expired = quest(service, issuer);
+
+        assertThrows(IllegalStateException.class, () -> service.cancel(
+            completed.id(), issuer, Instant.EPOCH.plusSeconds(2)
+        ));
+        assertThrows(IllegalStateException.class, () -> service.cancel(
+            cancelled.id(), issuer, Instant.EPOCH.plusSeconds(2)
+        ));
+        assertThrows(IllegalStateException.class, () -> service.cancel(
+            expired.id(), issuer, expired.expiresAt()
+        ));
+    }
+
+    @Test
+    void persistenceFailureLeavesQuestActiveAndRewardEscrowed() throws Exception {
+        Repository repository = new Repository();
+        QuestService service = new QuestService(repository);
+        UUID issuer = UUID.randomUUID();
+        Quest quest = quest(service, issuer);
+        QuestState before = service.state();
+        repository.fail = true;
+
+        assertThrows(IOException.class, () -> service.cancel(
+            quest.id(), issuer, Instant.EPOCH.plusSeconds(1)
+        ));
+
+        assertEquals(before, service.state());
+        assertEquals(before, repository.state);
+        assertEquals(QuestStatus.ACTIVE, service.state().quests().get(quest.id()).status());
+        assertTrue(service.state().claims().isEmpty());
+    }
+
+    @Test
+    void simultaneousCancellationAndCompletionSettleEscrowExactlyOnce() throws Exception {
+        Repository repository = new Repository();
+        QuestService service = new QuestService(repository);
+        UUID issuer = UUID.randomUUID();
+        Quest quest = quest(service, issuer);
+        CountDownLatch start = new CountDownLatch(1);
+        try (ExecutorService executor = Executors.newFixedThreadPool(2)) {
+            List<Future<Boolean>> attempts = new ArrayList<>();
+            attempts.add(executor.submit(() -> {
+                start.await();
+                try {
+                    service.cancel(quest.id(), issuer, Instant.EPOCH.plusSeconds(1));
+                    return true;
+                } catch (IllegalStateException exception) {
+                    return false;
+                }
+            }));
+            attempts.add(executor.submit(() -> {
+                start.await();
+                try {
+                    service.complete(
+                        quest.id(), new EscrowItem("STONE", 1, null),
+                        Instant.EPOCH.plusSeconds(1)
+                    );
+                    return true;
+                } catch (IllegalStateException exception) {
+                    return false;
+                }
+            }));
+            start.countDown();
+            assertEquals(1, attempts.stream().filter(attempt -> {
+                try {
+                    return attempt.get();
+                } catch (Exception exception) {
+                    throw new AssertionError(exception);
+                }
+            }).count());
+        }
+
+        QuestStatus status = service.state().quests().get(quest.id()).status();
+        assertTrue(status == QuestStatus.CANCELLED || status == QuestStatus.COMPLETED);
+        assertEquals(1, service.state().claims().get(issuer).size());
+        QuestClaim settlement = service.state().claims().get(issuer).getFirst();
+        if (status == QuestStatus.CANCELLED) {
+            assertEquals(quest.reward(), settlement.items());
+            assertTrue(service.state().notifications().isEmpty());
+        } else {
+            assertEquals(List.of(new EscrowItem("STONE", 1, null)), settlement.items());
+            assertEquals(1, service.state().notifications().size());
+        }
+    }
+
+    private static Quest quest(QuestService service, UUID issuer) throws IOException {
+        return service.create(
+            issuer, "Issuer", "STONE", 1,
+            List.of(new EscrowItem("DIAMOND", 2, null)), Instant.EPOCH
+        );
+    }
+
+    private static final class Repository implements QuestRepository {
+        private QuestState state = QuestState.empty();
+        private boolean fail;
+
+        @Override public QuestState load() { return state; }
+
+        @Override
+        public void save(QuestState candidate) throws IOException {
+            if (fail) {
+                throw new IOException("disk full");
+            }
+            state = candidate;
+        }
+    }
+}

src/test/java/games/dmg/spigotquestboard/QuestClaimControllerTest.java

@@ -0,0 +1,133 @@
+package games.dmg.spigotquestboard;
+
+import static org.junit.jupiter.api.Assertions.assertEquals;
+import static org.junit.jupiter.api.Assertions.assertThrows;
+import static org.junit.jupiter.api.Assertions.assertTrue;
+import static org.mockito.ArgumentMatchers.contains;
+import static org.mockito.Mockito.mock;
+import static org.mockito.Mockito.verify;
+import static org.mockito.Mockito.when;
+
+import java.io.IOException;
+import java.time.Instant;
+import java.util.List;
+import java.util.UUID;
+import org.bukkit.entity.Player;
+import org.junit.jupiter.api.Test;
+
+final class QuestClaimControllerTest {
+    @Test
+    void collectsEveryClaimAndClearlyDistinguishesItemsAndOverflow() throws Exception {
+        Repository repository = new Repository();
+        QuestService service = serviceWithAllClaimSources(repository);
+        UUID issuer = service.state().claims().keySet().iterator().next();
+        Player player = mock(Player.class);
+        when(player.getUniqueId()).thenReturn(issuer);
+        RecordingInventory inventory = new RecordingInventory(2);
+
+        ClaimCollectionResult result = new QuestClaimController(service, inventory).collect(player);
+
+        assertEquals(new ClaimCollectionResult(3, 6), result);
+        assertTrue(service.claimsFor(issuer).isEmpty());
+        verify(player).sendMessage(contains("delivered items from completed quest"));
+        verify(player).sendMessage(contains("returned reward from cancelled quest"));
+        verify(player).sendMessage(contains("returned reward from expired quest"));
+        verify(player).sendMessage(contains("dropped at your feet, protected for you"));
+    }
+
+    @Test
+    void deliveryFailureLeavesClaimPendingForRetry() throws Exception {
+        Repository repository = new Repository();
+        QuestService service = expiredService(repository);
+        UUID issuer = service.state().claims().keySet().iterator().next();
+        Player player = mock(Player.class);
+        when(player.getUniqueId()).thenReturn(issuer);
+        QuestClaimInventory inventory = items -> ignored -> {
+            throw new IllegalStateException("world rejected drop");
+        };
+
+        assertThrows(
+            IllegalStateException.class,
+            () -> new QuestClaimController(service, inventory).collect(player)
+        );
+
+        assertEquals(1, service.claimsFor(issuer).size());
+    }
+
+    @Test
+    void acknowledgementFailureRollsBackDeliveryAndLeavesClaimPending() throws Exception {
+        Repository repository = new Repository();
+        QuestService service = expiredService(repository);
+        UUID issuer = service.state().claims().keySet().iterator().next();
+        Player player = mock(Player.class);
+        when(player.getUniqueId()).thenReturn(issuer);
+        RecordingInventory inventory = new RecordingInventory(0);
+        repository.fail = true;
+
+        assertThrows(
+            IOException.class,
+            () -> new QuestClaimController(service, inventory).collect(player)
+        );
+
+        assertEquals(1, inventory.rollbacks);
+        assertEquals(1, service.claimsFor(issuer).size());
+    }
+
+    private static QuestService serviceWithAllClaimSources(Repository repository) throws Exception {
+        QuestService service = new QuestService(repository);
+        UUID issuer = UUID.randomUUID();
+        Quest completed = create(service, issuer, "STONE");
+        Quest cancelled = create(service, issuer, "DIRT");
+        Quest expired = create(service, issuer, "SAND");
+        service.complete(
+            completed.id(), new EscrowItem("STONE", 1, null), Instant.EPOCH.plusSeconds(1)
+        );
+        service.cancel(cancelled.id(), issuer, Instant.EPOCH.plusSeconds(1));
+        service.expire(expired.expiresAt());
+        return service;
+    }
+
+    private static QuestService expiredService(Repository repository) throws Exception {
+        QuestService service = new QuestService(repository);
+        Quest quest = create(service, UUID.randomUUID(), "STONE");
+        service.expire(quest.expiresAt());
+        return service;
+    }
+
+    private static Quest create(QuestService service, UUID issuer, String material)
+        throws IOException {
+        return service.create(
+            issuer, "Issuer", material, 1,
+            List.of(new EscrowItem("DIAMOND", 1, null)), Instant.EPOCH
+        );
+    }
+
+    private static final class RecordingInventory implements QuestClaimInventory {
+        private final int overflow;
+        private int rollbacks;
+
+        private RecordingInventory(int overflow) {
+            this.overflow = overflow;
+        }
+
+        @Override
+        public PreparedClaim prepare(List<EscrowItem> items) {
+            return player -> new Delivery() {
+                @Override public int overflowAmount() { return overflow; }
+                @Override public void rollback() { rollbacks++; }
+            };
+        }
+    }
+
+    private static final class Repository implements QuestRepository {
+        private QuestState state = QuestState.empty();
+        private boolean fail;
+        @Override public QuestState load() { return state; }
+        @Override public void save(QuestState candidate) throws IOException {
+            if (fail) {
+                throw new IOException("disk full");
+            }
+            state = candidate;
+        }
+    }
+}

src/test/java/games/dmg/spigotquestboard/QuestCommandTest.java

@@ -6,6 +6,7 @@ import static org.mockito.ArgumentMatchers.contains;
 import static org.mockito.Mockito.mock;
 import static org.mockito.Mockito.times;
 import static org.mockito.Mockito.verify;
+import static org.mockito.Mockito.verifyNoInteractions;
 import static org.mockito.Mockito.when;
 
 import java.time.Clock;
@@ -13,12 +14,147 @@ import java.time.Instant;
 import java.time.ZoneOffset;
 import java.util.List;
 import java.util.UUID;
+import org.bukkit.Location;
+import org.bukkit.World;
 import org.bukkit.command.Command;
 import org.bukkit.entity.Player;
 import org.junit.jupiter.api.Test;
 
 final class QuestCommandTest {
     private static final Instant NOW = Instant.parse("2026-09-05T03:00:00Z");
+    private static final UUID WORLD_ID =
+        UUID.fromString("00000000-0000-0000-0000-000000000099");
+
+    @Test
+    void disabledSettingGatesNonCreationCommandForms() throws Exception {
+        QuestCreationGateway creator = mock(QuestCreationGateway.class);
+        QuestBrowser browser = mock(QuestBrowser.class);
+        QuestCompletionGateway completer = mock(QuestCompletionGateway.class);
+        QuestCancellationGateway canceller = mock(QuestCancellationGateway.class);
+        QuestClaimGateway claimant = mock(QuestClaimGateway.class);
+        PlayerCommandSettings settings = new PlayerCommandSettings(
+            new PlayerCommandSettingsRepository() {
+                @Override public boolean loadEnabled() { return false; }
+                @Override public void saveEnabled(boolean enabled) { }
+            }
+        );
+        QuestCommand executor = new QuestCommand(
+            creator, browser, completer, canceller, claimant,
+            Clock.fixed(NOW, ZoneOffset.UTC), settings
+        );
+        Player player = mock(Player.class);
+        Command command = mock(Command.class);
+        List<String[]> forms = List.of(
+            new String[] {},
+            new String[] {"list"},
+            new String[] {"complete", "quest-id"},
+            new String[] {"cancel", "quest-id"},
+            new String[] {"claim"}
+        );
+
+        for (String[] form : forms) {
+            assertTrue(executor.onCommand(player, command, "quests", form));
+        }
+
+        verify(player, times(forms.size())).sendMessage(
+            "Player quest commands are disabled. Use a physical quest board instead."
+        );
+        assertTrue(executor.onTabComplete(
+            player, command, "quests", new String[] {""}
+        ).isEmpty());
+        verifyNoInteractions(creator, browser, completer, canceller, claimant);
+    }
+
+    @Test
+    void disabledSettingAllowsNearbyCreationAndOnlyCreationAutocomplete() throws Exception {
+        RecordingCreator creator = new RecordingCreator();
+        PlayerCommandSettings settings = settings(false);
+        BoardProximity proximity = (worldId, x, y, z, maximumDistance) -> {
+            assertEquals(WORLD_ID, worldId);
+            assertEquals(4.0, x);
+            assertEquals(3.0, y);
+            assertEquals(0.0, z);
+            assertEquals(5.0, maximumDistance);
+            return true;
+        };
+        QuestCommand executor = new QuestCommand(
+            creator, now -> List.of(), null, null, null,
+            Clock.fixed(NOW, ZoneOffset.UTC), settings, proximity
+        );
+        Player player = playerAt(4.0, 3.0, 0.0);
+        Command command = mock(Command.class);
+
+        assertTrue(executor.onCommand(
+            player, command, "quests", new String[] {"create", "stone", "1"}
+        ));
+
+        assertEquals(1, creator.calls);
+        assertEquals(List.of("create"), executor.onTabComplete(
+            player, command, "quests", new String[] {""}
+        ));
+        assertTrue(executor.onTabComplete(
+            player, command, "quests", new String[] {"li"}
+        ).isEmpty());
+        assertEquals(List.of("STONE", "STONE_BRICKS"), executor.onTabComplete(
+            player, command, "quests", new String[] {"create", "sto"}
+        ));
+        assertEquals(List.of("1", "16", "32", "64"), executor.onTabComplete(
+            player, command, "quests", new String[] {"create", "stone", ""}
+        ));
+        assertTrue(executor.onTabComplete(
+            player, command, "quests", new String[] {"complete", ""}
+        ).isEmpty());
+    }
+
+    @Test
+    void disabledSettingRejectsAwayCreationBeforeCreatorOrEscrowGateway() throws Exception {
+        QuestCreationGateway creator = mock(QuestCreationGateway.class);
+        QuestCommand executor = new QuestCommand(
+            creator, mock(QuestBrowser.class), null, null, null,
+            Clock.fixed(NOW, ZoneOffset.UTC), settings(false),
+            (worldId, x, y, z, maximumDistance) -> false
+        );
+        Player player = playerAt(5.01, 0.0, 0.0);
+        Command command = mock(Command.class);
+
+        assertTrue(executor.onCommand(
+            player, command, "quests", new String[] {"create", "stone", "1"}
+        ));
+
+        verify(player).sendMessage("Move closer to a quest board to create a quest by command.");
+        verifyNoInteractions(creator);
+        assertTrue(executor.onTabComplete(
+            player, command, "quests", new String[] {""}
+        ).isEmpty());
+        assertTrue(executor.onTabComplete(
+            player, command, "quests", new String[] {"create", "sto"}
+        ).isEmpty());
+    }
+
+    @Test
+    void enabledSettingPreservesAllCommandsWithoutConsultingProximity() throws Exception {
+        RecordingCreator creator = new RecordingCreator();
+        QuestBrowser browser = now -> List.of(creator.quest(1));
+        QuestCommand executor = new QuestCommand(
+            creator, browser, null, null, null, Clock.fixed(NOW, ZoneOffset.UTC),
+            settings(true),
+            (worldId, x, y, z, maximumDistance) -> {
+                throw new AssertionError("Enabled commands must bypass board proximity");
+            }
+        );
+        Player player = mock(Player.class);
+        Command command = mock(Command.class);
+
+        assertTrue(executor.onCommand(
+            player, command, "quests", new String[] {"create", "stone", "1"}
+        ));
+        assertTrue(executor.onCommand(player, command, "quests", new String[] {"list"}));
+        assertEquals(List.of("create"), executor.onTabComplete(
+            player, command, "quests", new String[] {"cr"}
+        ));
+
+        assertEquals(1, creator.calls);
+    }
 
     @Test
     void routesValidatedCreateArgumentsWithCurrentUtcTime() {
@@ -86,6 +222,66 @@ final class QuestCommandTest {
         verify(player).sendMessage("Quest quantity must be a positive whole number.");
     }
 
+    @Test
+    void completeCommandRoutesPlayerAndCurrentTimeToEquivalentGateway() {
+        RecordingCreator creator = new RecordingCreator();
+        RecordingCompleter completer = new RecordingCompleter();
+        QuestCommand executor = new QuestCommand(
+            creator, now -> List.of(), completer, Clock.fixed(NOW, ZoneOffset.UTC)
+        );
+        Player player = mock(Player.class);
+        String id = UUID.randomUUID().toString();
+
+        assertTrue(executor.onCommand(
+            player, mock(Command.class), "quests", new String[] {"complete", id}
+        ));
+
+        assertEquals(player, completer.player);
+        assertEquals(id, completer.questId);
+        assertEquals(NOW, completer.completedAt);
+    }
+
+    @Test
+    void claimCommandUsesTheSameCollectionGateway() {
+        RecordingCreator creator = new RecordingCreator();
+        Player player = mock(Player.class);
+        java.util.concurrent.atomic.AtomicReference<Player> claimantPlayer =
+            new java.util.concurrent.atomic.AtomicReference<>();
+        QuestClaimGateway claimant = claimingPlayer -> {
+            claimantPlayer.set(claimingPlayer);
+            return new ClaimCollectionResult(1, 0);
+        };
+        QuestCommand executor = new QuestCommand(
+            creator, now -> List.of(), null, null, claimant,
+            Clock.fixed(NOW, ZoneOffset.UTC)
+        );
+
+        assertTrue(executor.onCommand(
+            player, mock(Command.class), "quests", new String[] {"claim"}
+        ));
+
+        assertEquals(player, claimantPlayer.get());
+    }
+
+    @Test
+    void cancelCommandRoutesPlayerAndCurrentTimeToEquivalentGateway() {
+        RecordingCreator creator = new RecordingCreator();
+        RecordingCanceller canceller = new RecordingCanceller();
+        QuestCommand executor = new QuestCommand(
+            creator, now -> List.of(), null, canceller, Clock.fixed(NOW, ZoneOffset.UTC)
+        );
+        Player player = mock(Player.class);
+        String id = UUID.randomUUID().toString();
+
+        assertTrue(executor.onCommand(
+            player, mock(Command.class), "quests", new String[] {"cancel", id}
+        ));
+
+        assertEquals(player, canceller.player);
+        assertEquals(id, canceller.questId);
+        assertEquals(NOW, canceller.cancelledAt);
+    }
+
     @Test
     void questIdentifierAutocompleteOnlyUsesActiveAndOwnedQuests() {
         RecordingCreator creator = new RecordingCreator();
@@ -120,6 +316,10 @@ final class QuestCommandTest {
             executor.onTabComplete(player, command, "quests", new String[] {"cr"}));
         assertEquals(List.of("list"),
             executor.onTabComplete(player, command, "quests", new String[] {"li"}));
+        assertEquals(List.of("cancel"),
+            executor.onTabComplete(player, command, "quests", new String[] {"ca"}));
+        assertEquals(List.of("claim"),
+            executor.onTabComplete(player, command, "quests", new String[] {"cl"}));
         assertEquals(List.of("STONE", "STONE_BRICKS"), executor.onTabComplete(
             player, command, "quests", new String[] {"create", "sto"}
         ));
@@ -132,6 +332,23 @@ final class QuestCommandTest {
         ).isEmpty());
     }
 
+    private static PlayerCommandSettings settings(boolean enabled) throws Exception {
+        return new PlayerCommandSettings(new PlayerCommandSettingsRepository() {
+            @Override public boolean loadEnabled() { return enabled; }
+            @Override public void saveEnabled(boolean newValue) { }
+        });
+    }
+
+    private static Player playerAt(double x, double y, double z) {
+        World world = mock(World.class);
+        when(world.getUID()).thenReturn(WORLD_ID);
+        Location location = new Location(world, x, y, z);
+        Player player = mock(Player.class);
+        when(player.getWorld()).thenReturn(world);
+        when(player.getLocation()).thenReturn(location);
+        return player;
+    }
+
     private static QuestCommand command(RecordingCreator creator) {
         return command(creator, now -> List.of());
     }
@@ -140,6 +357,34 @@ final class QuestCommandTest {
         return new QuestCommand(creator, browser, Clock.fixed(NOW, ZoneOffset.UTC));
     }
 
+    private static final class RecordingCanceller implements QuestCancellationGateway {
+        private Player player;
+        private String questId;
+        private Instant cancelledAt;
+
+        @Override
+        public QuestClaim cancel(Player cancellingPlayer, String id, Instant instant) {
+            player = cancellingPlayer;
+            questId = id;
+            cancelledAt = instant;
+            return null;
+        }
+    }
+
+    private static final class RecordingCompleter implements QuestCompletionGateway {
+        private Player player;
+        private String questId;
+        private Instant completedAt;
+
+        @Override
+        public QuestCompletion complete(Player completingPlayer, String id, Instant instant) {
+            player = completingPlayer;
+            questId = id;
+            completedAt = instant;
+            return null;
+        }
+    }
+
     private static final class RecordingCreator implements QuestCreationGateway {
         private Player player;
         private String material;
@@ -172,7 +417,7 @@ final class QuestCommandTest {
         }
 
         @Override
-        public List<String> suggestBlockMaterials(String prefix) {
+        public List<String> suggestItemMaterials(String prefix) {
             suggestionPrefix = prefix;
             return List.of("STONE", "STONE_BRICKS");
         }

src/test/java/games/dmg/spigotquestboard/QuestCompletionAtomicityTest.java

@@ -0,0 +1,118 @@
+package games.dmg.spigotquestboard;
+
+import static org.junit.jupiter.api.Assertions.assertEquals;
+import static org.junit.jupiter.api.Assertions.assertThrows;
+import static org.junit.jupiter.api.Assertions.assertTrue;
+
+import java.io.IOException;
+import java.time.Instant;
+import java.util.ArrayList;
+import java.util.List;
+import java.util.UUID;
+import java.util.concurrent.CountDownLatch;
+import java.util.concurrent.ExecutorService;
+import java.util.concurrent.Executors;
+import java.util.concurrent.Future;
+import org.junit.jupiter.api.Test;
+
+final class QuestCompletionAtomicityTest {
+    @Test
+    void persistenceFailureChangesNoDurableOrInMemoryState() throws Exception {
+        FailingRepository repository = new FailingRepository();
+        QuestService service = new QuestService(repository);
+        Quest quest = service.create(
+            UUID.randomUUID(), "Issuer", "STONE", 2,
+            List.of(new EscrowItem("DIAMOND", 1, null)), Instant.EPOCH
+        );
+        QuestState before = service.state();
+        repository.fail = true;
+
+        assertThrows(IOException.class, () -> service.complete(
+            quest.id(), new EscrowItem("STONE", 2, null), Instant.EPOCH.plusSeconds(1)
+        ));
+
+        assertEquals(before, service.state());
+        assertEquals(before, repository.state);
+    }
+
+    @Test
+    void rejectsWrongMaterialQuantityExpiredAndAlreadyCompleted() throws Exception {
+        FailingRepository repository = new FailingRepository();
+        QuestService service = new QuestService(repository);
+        Quest quest = service.create(
+            UUID.randomUUID(), "Issuer", "STONE", 2,
+            List.of(new EscrowItem("DIAMOND", 1, null)), Instant.EPOCH
+        );
+
+        assertThrows(IllegalArgumentException.class, () -> service.complete(
+            quest.id(), new EscrowItem("DIRT", 2, null), Instant.EPOCH.plusSeconds(1)
+        ));
+        assertThrows(IllegalArgumentException.class, () -> service.complete(
+            quest.id(), new EscrowItem("STONE", 1, null), Instant.EPOCH.plusSeconds(1)
+        ));
+        assertThrows(IllegalStateException.class, () -> service.complete(
+            quest.id(), new EscrowItem("STONE", 2, null), quest.expiresAt()
+        ));
+        service.complete(
+            quest.id(), new EscrowItem("STONE", 2, null), Instant.EPOCH.plusSeconds(1)
+        );
+        assertThrows(IllegalStateException.class, () -> service.complete(
+            quest.id(), new EscrowItem("STONE", 2, null), Instant.EPOCH.plusSeconds(2)
+        ));
+        assertTrue(service.activeQuests(Instant.EPOCH.plusSeconds(2)).isEmpty());
+    }
+
+    @Test
+    void simultaneousAttemptsSettleExactlyOnce() throws Exception {
+        FailingRepository repository = new FailingRepository();
+        QuestService service = new QuestService(repository);
+        UUID issuer = UUID.randomUUID();
+        Quest quest = service.create(
+            issuer, "Issuer", "STONE", 1,
+            List.of(new EscrowItem("DIAMOND", 1, null)), Instant.EPOCH
+        );
+        CountDownLatch start = new CountDownLatch(1);
+        try (ExecutorService executor = Executors.newFixedThreadPool(2)) {
+            List<Future<Boolean>> attempts = new ArrayList<>();
+            for (int index = 0; index < 2; index++) {
+                attempts.add(executor.submit(() -> {
+                    start.await();
+                    try {
+                        service.complete(
+                            quest.id(), new EscrowItem("STONE", 1, null),
+                            Instant.EPOCH.plusSeconds(1)
+                        );
+                        return true;
+                    } catch (IllegalStateException exception) {
+                        return false;
+                    }
+                }));
+            }
+            start.countDown();
+            assertEquals(1, attempts.stream().filter(attempt -> {
+                try {
+                    return attempt.get();
+                } catch (Exception exception) {
+                    throw new AssertionError(exception);
+                }
+            }).count());
+        }
+        assertEquals(1, service.state().claims().get(issuer).size());
+        assertEquals(1, service.state().notifications().size());
+    }
+
+    private static final class FailingRepository implements QuestRepository {
+        private QuestState state = QuestState.empty();
+        private boolean fail;
+
+        @Override public QuestState load() { return state; }
+
+        @Override
+        public void save(QuestState candidate) throws IOException {
+            if (fail) {
+                throw new IOException("disk full");
+            }
+            state = candidate;
+        }
+    }
+}

src/test/java/games/dmg/spigotquestboard/QuestCompletionControllerTest.java

@@ -0,0 +1,142 @@
+package games.dmg.spigotquestboard;
+
+import static org.junit.jupiter.api.Assertions.assertEquals;
+import static org.junit.jupiter.api.Assertions.assertFalse;
+import static org.junit.jupiter.api.Assertions.assertThrows;
+import static org.junit.jupiter.api.Assertions.assertTrue;
+import static org.mockito.ArgumentMatchers.contains;
+import static org.mockito.Mockito.mock;
+import static org.mockito.Mockito.never;
+import static org.mockito.Mockito.verify;
+
+import java.io.IOException;
+import java.time.Instant;
+import java.util.List;
+import java.util.UUID;
+import org.bukkit.entity.Player;
+import org.junit.jupiter.api.Test;
+
+final class QuestCompletionControllerTest {
+    @Test
+    void removesExactDeliverySettlesRewardReportsOverflowAndNotifies() throws Exception {
+        Repository repository = new Repository();
+        QuestService service = new QuestService(repository);
+        UUID issuer = UUID.randomUUID();
+        Quest quest = quest(service, issuer);
+        Inventory inventory = new Inventory();
+        inventory.overflow = 2;
+        RecordingNotifier notifier = new RecordingNotifier();
+        QuestCompletionController controller = new QuestCompletionController(
+            service, inventory, notifier
+        );
+        Player player = mock(Player.class);
+
+        controller.complete(player, quest.id().toString(), Instant.EPOCH.plusSeconds(1));
+
+        assertEquals("STONE", inventory.material);
+        assertEquals(3, inventory.amount);
+        assertTrue(inventory.granted);
+        assertFalse(inventory.rolledBack);
+        assertEquals(issuer, notifier.issuer);
+        assertEquals(
+            List.of(new EscrowItem("STONE", 3, null)),
+            service.state().claims().get(issuer).getFirst().items()
+        );
+        verify(player).sendMessage(contains("exact escrowed reward"));
+        verify(player).sendMessage(contains("dropped safely at your feet"));
+    }
+
+    @Test
+    void inventoryValidationFailureConsumesAndReleasesNothing() throws Exception {
+        Repository repository = new Repository();
+        QuestService service = new QuestService(repository);
+        Quest quest = quest(service, UUID.randomUUID());
+        Inventory inventory = new Inventory();
+        inventory.insufficient = true;
+        Player player = mock(Player.class);
+
+        assertThrows(IllegalArgumentException.class, () -> new QuestCompletionController(
+            service, inventory, ignored -> { }
+        ).complete(player, quest.id().toString(), Instant.EPOCH.plusSeconds(1)));
+
+        assertFalse(inventory.granted);
+        assertEquals(QuestStatus.ACTIVE, service.state().quests().get(quest.id()).status());
+        assertTrue(service.state().claims().isEmpty());
+        verify(player, never()).sendMessage(contains("completed"));
+    }
+
+    @Test
+    void persistenceFailureRollsBackDeliveryAndDoesNotGrantReward() throws Exception {
+        Repository repository = new Repository();
+        QuestService service = new QuestService(repository);
+        Quest quest = quest(service, UUID.randomUUID());
+        Inventory inventory = new Inventory();
+        repository.fail = true;
+
+        assertThrows(IOException.class, () -> new QuestCompletionController(
+            service, inventory, ignored -> { }
+        ).complete(mock(Player.class), quest.id().toString(), Instant.EPOCH.plusSeconds(1)));
+
+        assertTrue(inventory.rolledBack);
+        assertFalse(inventory.granted);
+        assertEquals(QuestStatus.ACTIVE, service.state().quests().get(quest.id()).status());
+    }
+
+    private static Quest quest(QuestService service, UUID issuer) throws IOException {
+        return service.create(
+            issuer, "Issuer", "STONE", 3,
+            List.of(new EscrowItem("DIAMOND", 2, null)), Instant.EPOCH
+        );
+    }
+
+    private static final class Inventory implements QuestCompletionInventory {
+        private String material;
+        private int amount;
+        private boolean insufficient;
+        private boolean rolledBack;
+        private boolean granted;
+        private int overflow;
+
+        @Override
+        public RemovedDelivery remove(Player player, String requestedMaterial, int requestedAmount) {
+            material = requestedMaterial;
+            amount = requestedAmount;
+            if (insufficient) {
+                throw new IllegalArgumentException("not enough blocks");
+            }
+            return new RemovedDelivery() {
+                @Override
+                public List<EscrowItem> items() {
+                    return List.of(new EscrowItem(requestedMaterial, requestedAmount, null));
+                }
+
+                @Override public void rollback() { rolledBack = true; }
+            };
+        }
+
+        @Override
+        public PreparedReward prepare(List<EscrowItem> reward) {
+            return player -> {
+                granted = true;
+                return overflow;
+            };
+        }
+    }
+
+    private static final class RecordingNotifier implements IssuerNotifier {
+        private UUID issuer;
+        @Override public void notifyIfOnline(UUID issuerId) { issuer = issuerId; }
+    }
+
+    private static final class Repository implements QuestRepository {
+        private QuestState state = QuestState.empty();
+        private boolean fail;
+        @Override public QuestState load() { return state; }
+        @Override public void save(QuestState candidate) throws IOException {
+            if (fail) {
+                throw new IOException("disk full");
+            }
+            state = candidate;
+        }
+    }
+}

src/test/java/games/dmg/spigotquestboard/QuestCompletionServiceTest.java

@@ -0,0 +1,37 @@
+package games.dmg.spigotquestboard;
+
+import static org.junit.jupiter.api.Assertions.assertEquals;
+import static org.junit.jupiter.api.Assertions.assertTrue;
+
+import java.time.Instant;
+import java.util.List;
+import java.util.UUID;
+import org.junit.jupiter.api.Test;
+
+final class QuestCompletionServiceTest {
+    @Test
+    void completesOnceAndHoldsDeliveredBlocksForIssuer() throws Exception {
+        MemoryQuestRepository repository = new MemoryQuestRepository();
+        QuestService service = new QuestService(repository);
+        UUID issuer = UUID.randomUUID();
+        Quest quest = service.create(
+            issuer, "Issuer", "STONE", 64,
+            List.of(new EscrowItem("DIAMOND", 3, null)), Instant.EPOCH
+        );
+
+        QuestCompletion completion = service.complete(
+            quest.id(), new EscrowItem("STONE", 64, null), Instant.EPOCH.plusSeconds(1)
+        );
+
+        assertEquals(QuestStatus.COMPLETED, service.state().quests().get(quest.id()).status());
+        assertEquals(quest.reward(), completion.reward());
+        assertTrue(service.state().claims().get(issuer).stream()
+            .anyMatch(claim -> claim.items().equals(List.of(new EscrowItem("STONE", 64, null)))));
+    }
+
+    private static final class MemoryQuestRepository implements QuestRepository {
+        private QuestState state = QuestState.empty();
+        @Override public QuestState load() { return state; }
+        @Override public void save(QuestState state) { this.state = state; }
+    }
+}

src/test/java/games/dmg/spigotquestboard/QuestCreationControllerTest.java

@@ -71,9 +71,9 @@ final class QuestCreationControllerTest {
     private static QuestCreationController controller(
         MemoryQuestRepository repository, HeldRewardInventory inventory
     ) throws IOException {
-        BlockMaterialCatalog catalog = new BlockMaterialCatalog() {
+        ItemMaterialCatalog catalog = new ItemMaterialCatalog() {
             @Override
-            public Optional<String> normalizeBlock(String input) {
+            public Optional<String> normalizeItem(String input) {
                 return "stone".equalsIgnoreCase(input) ? Optional.of("STONE") : Optional.empty();
             }
 

src/test/java/games/dmg/spigotquestboard/QuestExpiryAndClaimServiceTest.java

@@ -0,0 +1,127 @@
+package games.dmg.spigotquestboard;
+
+import static org.junit.jupiter.api.Assertions.assertEquals;
+import static org.junit.jupiter.api.Assertions.assertThrows;
+import static org.junit.jupiter.api.Assertions.assertTrue;
+
+import java.io.IOException;
+import java.time.Instant;
+import java.util.List;
+import java.util.UUID;
+import org.junit.jupiter.api.Test;
+
+final class QuestExpiryAndClaimServiceTest {
+    @Test
+    void expiryReturnsExactRewardAsTypedClaimAndAcknowledgementRemovesIt() throws Exception {
+        MemoryQuestRepository repository = new MemoryQuestRepository();
+        QuestService service = new QuestService(repository);
+        UUID issuer = UUID.randomUUID();
+        EscrowItem reward = new EscrowItem("DIAMOND", 3, "exact-data");
+        Quest quest = service.create(
+            issuer, "Issuer", "STONE", 64, List.of(reward), Instant.EPOCH
+        );
+
+        service.expire(quest.expiresAt());
+        List<QuestClaim> claims = service.claimsFor(issuer);
+
+        assertEquals(QuestStatus.EXPIRED, service.state().quests().get(quest.id()).status());
+        assertEquals(List.of(reward), claims.getFirst().items());
+        assertEquals(QuestClaimSource.EXPIRATION, claims.getFirst().source());
+        assertEquals(QuestClaimType.RETURNED_REWARD, claims.getFirst().type());
+        service.acknowledgeClaim(issuer, claims.getFirst().id());
+        assertTrue(service.claimsFor(issuer).isEmpty());
+    }
+
+    @Test
+    void sevenDayBoundaryIsExclusiveBeforeAndDueExactlyAtExpiration() throws Exception {
+        QuestService service = new QuestService(new MemoryQuestRepository());
+        Quest quest = create(service, UUID.randomUUID());
+
+        assertTrue(service.expire(quest.expiresAt().minusNanos(1)).isEmpty());
+        assertEquals(QuestStatus.ACTIVE, service.state().quests().get(quest.id()).status());
+
+        assertEquals(1, service.expire(quest.expiresAt()).size());
+        assertEquals(QuestStatus.EXPIRED, service.state().quests().get(quest.id()).status());
+        assertTrue(service.expire(quest.expiresAt().plusSeconds(1)).isEmpty());
+        assertEquals(1, service.claimsFor(quest.issuerId()).size());
+    }
+
+    @Test
+    void completionCancellationAndExpirationClaimsKeepTheirDistinctSources() throws Exception {
+        QuestService service = new QuestService(new MemoryQuestRepository());
+        UUID issuer = UUID.randomUUID();
+        Quest completed = create(service, issuer);
+        Quest cancelled = service.create(
+            issuer, "Issuer", "DIRT", 1,
+            List.of(new EscrowItem("EMERALD", 2, null)), Instant.EPOCH
+        );
+        Quest expired = service.create(
+            issuer, "Issuer", "SAND", 1,
+            List.of(new EscrowItem("GOLD_INGOT", 4, null)), Instant.EPOCH
+        );
+
+        service.complete(
+            completed.id(), new EscrowItem("STONE", 1, null), Instant.EPOCH.plusSeconds(1)
+        );
+        service.cancel(cancelled.id(), issuer, Instant.EPOCH.plusSeconds(1));
+        service.expire(expired.expiresAt());
+
+        assertEquals(
+            List.of(
+                QuestClaimSource.COMPLETION,
+                QuestClaimSource.CANCELLATION,
+                QuestClaimSource.EXPIRATION
+            ),
+            service.claimsFor(issuer).stream().map(QuestClaim::source).toList()
+        );
+        assertEquals(
+            List.of(
+                QuestClaimType.DELIVERED_BLOCKS,
+                QuestClaimType.RETURNED_REWARD,
+                QuestClaimType.RETURNED_REWARD
+            ),
+            service.claimsFor(issuer).stream().map(QuestClaim::type).toList()
+        );
+    }
+
+    @Test
+    void failedExpirationPersistsNothingAndCanBeRetriedWithoutDuplication() throws Exception {
+        MemoryQuestRepository repository = new MemoryQuestRepository();
+        QuestService service = new QuestService(repository);
+        Quest quest = create(service, UUID.randomUUID());
+        repository.fail = true;
+
+        assertThrows(IOException.class, () -> service.expire(quest.expiresAt()));
+        assertEquals(QuestStatus.ACTIVE, service.state().quests().get(quest.id()).status());
+        assertTrue(service.claimsFor(quest.issuerId()).isEmpty());
+        assertTrue(service.pendingNotifications(quest.issuerId()).isEmpty());
+
+        repository.fail = false;
+        service.expire(quest.expiresAt());
+        service.expire(quest.expiresAt());
+        assertEquals(1, service.claimsFor(quest.issuerId()).size());
+        assertEquals(1, service.pendingNotifications(quest.issuerId()).size());
+    }
+
+    private static Quest create(QuestService service, UUID issuer) throws IOException {
+        return service.create(
+            issuer, "Issuer", "STONE", 1,
+            List.of(new EscrowItem("DIAMOND", 3, null)), Instant.EPOCH
+        );
+    }
+
+    private static final class MemoryQuestRepository implements QuestRepository {
+        private QuestState state = QuestState.empty();
+        private boolean fail;
+
+        @Override public QuestState load() { return state; }
+
+        @Override
+        public void save(QuestState candidate) throws IOException {
+            if (fail) {
+                throw new IOException("disk full");
+            }
+            state = candidate;
+        }
+    }
+}

src/test/java/games/dmg/spigotquestboard/QuestExpiryTaskTest.java

@@ -0,0 +1,44 @@
+package games.dmg.spigotquestboard;
+
+import static org.junit.jupiter.api.Assertions.assertEquals;
+
+import java.time.Clock;
+import java.time.Instant;
+import java.time.ZoneOffset;
+import java.util.List;
+import java.util.UUID;
+import java.util.concurrent.atomic.AtomicReference;
+import java.util.logging.Logger;
+import org.junit.jupiter.api.Test;
+
+final class QuestExpiryTaskTest {
+    @Test
+    void scheduledPassExpiresDueQuestAndRequestsImmediateOnlineNotification() throws Exception {
+        Instant boundary = Instant.parse("2026-09-12T03:00:00Z");
+        Repository repository = new Repository();
+        QuestService service = new QuestService(repository);
+        UUID issuer = UUID.randomUUID();
+        service.create(
+            issuer, "Issuer", "STONE", 1,
+            List.of(new EscrowItem("DIAMOND", 1, null)),
+            boundary.minusSeconds(604800)
+        );
+        AtomicReference<UUID> notified = new AtomicReference<>();
+        QuestExpiryTask task = new QuestExpiryTask(
+            service, notified::set, Clock.fixed(boundary, ZoneOffset.UTC),
+            Logger.getAnonymousLogger()
+        );
+
+        task.run();
+
+        assertEquals(issuer, notified.get());
+        assertEquals(1, service.pendingNotifications(issuer).size());
+        assertEquals(QuestStatus.EXPIRED, service.state().quests().values().iterator().next().status());
+    }
+
+    private static final class Repository implements QuestRepository {
+        private QuestState state = QuestState.empty();
+        @Override public QuestState load() { return state; }
+        @Override public void save(QuestState candidate) { state = candidate; }
+    }
+}

src/test/java/games/dmg/spigotquestboard/QuestListingFormatterTest.java

@@ -32,6 +32,19 @@ final class QuestListingFormatterTest {
         assertTrue(listing.contains("Time remaining: 1d 1h 1m 1s"));
     }
 
+    @Test
+    void showsCustomRewardNameTogetherWithMaterialType() {
+        Quest quest = quest(
+            NOW.plusSeconds(60),
+            List.of(new EscrowItem("PAPER", 1, "opaque-exact-data", "Shopping List"))
+        );
+
+        String listing = QuestListingFormatter.format(quest, NOW);
+
+        assertTrue(listing.contains("1 × Shopping List (PAPER)"));
+        assertFalse(listing.contains("PAPER (with exact item data)"));
+    }
+
     @Test
     void roundsAnActiveSubsecondBoundaryUpToOneSecond() {
         Quest quest = quest(NOW.plusNanos(1), List.of(new EscrowItem("DIAMOND", 1, null)));

src/test/java/games/dmg/spigotquestboard/YamlBoardRepositoryTest.java

@@ -3,6 +3,7 @@ package games.dmg.spigotquestboard;
 import static org.junit.jupiter.api.Assertions.assertEquals;
 import static org.junit.jupiter.api.Assertions.assertTrue;
 
+import java.nio.file.Files;
 import java.nio.file.Path;
 import java.util.Set;
 import java.util.UUID;
@@ -21,6 +22,45 @@ final class YamlBoardRepositoryTest {
         assertTrue(repository.load().boards().isEmpty());
     }
 
+    @Test
+    void loadsExistingSingleLocationBoardsFileWithoutMigration() throws Exception {
+        Path path = temporaryDirectory.resolve("boards.yml");
+        Files.writeString(path, """
+            boards:
+            - world-id: 00000000-0000-0000-0000-000000000001
+              world-name: survival
+              x: 4
+              y: 70
+              z: -8
+            """);
+
+        BoardState state = new YamlBoardRepository(path).load();
+
+        assertEquals(Set.of(new RegisteredBoard(
+            new BoardId(UUID.fromString("00000000-0000-0000-0000-000000000001"), 4, 70, -8),
+            "survival"
+        )), state.boards());
+    }
+
+    @Test
+    void persistsAllGeneratedInteractionLocationsAcrossRegistryRestart() throws Exception {
+        UUID worldId = UUID.fromString("00000000-0000-0000-0000-000000000003");
+        PhysicalBoardPlan plan = PhysicalBoardPlan.create(
+            new BoardId(worldId, 10, 64, 20), BoardFacing.WEST
+        );
+        Set<RegisteredBoard> generated = plan.interactionLocations().stream()
+            .map(location -> new RegisteredBoard(location, "survival"))
+            .collect(java.util.stream.Collectors.toSet());
+        Path path = temporaryDirectory.resolve("boards.yml");
+        BoardRegistry first = new BoardRegistry(new YamlBoardRepository(path));
+
+        assertEquals(BoardRegistrationResult.CREATED, first.registerAll(generated));
+        BoardRegistry restarted = new BoardRegistry(new YamlBoardRepository(path));
+
+        assertEquals(17, restarted.size());
+        assertTrue(generated.stream().allMatch(board -> restarted.contains(board.id())));
+    }
+
     @Test
     void roundTripsWorldIdentityAndCoordinates() throws Exception {
         Path path = temporaryDirectory.resolve("boards.yml");

src/test/java/games/dmg/spigotquestboard/YamlQuestRepositoryTest.java

@@ -1,8 +1,11 @@
 package games.dmg.spigotquestboard;
 
 import static org.junit.jupiter.api.Assertions.assertEquals;
+import static org.junit.jupiter.api.Assertions.assertNull;
 import static org.junit.jupiter.api.Assertions.assertThrows;
 import static org.junit.jupiter.api.Assertions.assertTrue;
+import static org.mockito.Mockito.mock;
+import static org.mockito.Mockito.when;
 
 import java.io.IOException;
 import java.nio.file.Files;
@@ -12,8 +15,14 @@ import java.util.Base64;
 import java.util.List;
 import java.util.Map;
 import java.util.UUID;
+import net.kyori.adventure.text.Component;
+import org.bukkit.Material;
+import org.bukkit.inventory.ItemStack;
+import org.bukkit.inventory.meta.ItemMeta;
 import org.junit.jupiter.api.Test;
 import org.junit.jupiter.api.io.TempDir;
+import org.mockito.MockedStatic;
+import org.mockito.Mockito;
 
 final class YamlQuestRepositoryTest {
     @TempDir Path temporaryDirectory;
@@ -53,6 +62,90 @@ final class YamlQuestRepositoryTest {
         assertTrue(yaml.contains(itemData));
     }
 
+    @Test
+    void persistsCustomNamesForRewardAndClaimItems() throws Exception {
+        Path path = temporaryDirectory.resolve("quests.yml");
+        YamlQuestRepository repository = new YamlQuestRepository(path);
+        UUID ownerId = UUID.randomUUID();
+        UUID questId = UUID.randomUUID();
+        Quest quest = new Quest(
+            questId, ownerId, "Issuer", "STONE", 1,
+            List.of(new EscrowItem("PAPER", 1, "reward-data", "Shopping List")),
+            Instant.parse("2026-09-05T03:00:00Z"),
+            Instant.parse("2026-09-12T03:00:00Z"), QuestStatus.COMPLETED
+        );
+        QuestClaim claim = new QuestClaim(
+            UUID.randomUUID(), questId, ownerId,
+            List.of(new EscrowItem("BOOK", 1, "claim-data", "Field Notes")),
+            Instant.parse("2026-09-05T03:01:00Z")
+        );
+        QuestState state = new QuestState(
+            Map.of(questId, quest), Map.of(ownerId, List.of(claim)), Map.of()
+        );
+
+        repository.save(state);
+
+        assertEquals(state, repository.load());
+        String yaml = Files.readString(path);
+        assertTrue(yaml.contains("custom-name: Shopping List"));
+        assertTrue(yaml.contains("custom-name: Field Notes"));
+    }
+
+    @Test
+    void infersHistoricalCustomNameFromExactDataAndPersistsItOnNextSave() throws Exception {
+        Path path = temporaryDirectory.resolve("quests.yml");
+        String itemData = Base64.getEncoder().encodeToString(new byte[] {7});
+        writeHistoricalQuest(path, itemData);
+        ItemStack stack = mock(ItemStack.class);
+        ItemMeta metadata = mock(ItemMeta.class);
+        when(stack.getType()).thenReturn(Material.PAPER);
+        when(stack.getAmount()).thenReturn(1);
+        when(stack.hasItemMeta()).thenReturn(true);
+        when(stack.getItemMeta()).thenReturn(metadata);
+        when(metadata.hasCustomName()).thenReturn(true);
+        when(metadata.customName()).thenReturn(Component.text("Archived List"));
+        YamlQuestRepository repository = new YamlQuestRepository(path);
+
+        QuestState loaded;
+        try (MockedStatic<ItemStack> itemStacks = Mockito.mockStatic(ItemStack.class)) {
+            itemStacks.when(() -> ItemStack.deserializeBytes(Mockito.any(byte[].class)))
+                .thenReturn(stack);
+            loaded = repository.load();
+        }
+
+        assertEquals("Archived List", loaded.quests().values().iterator().next()
+            .reward().getFirst().customName());
+        assertEquals("Archived List", loaded.claims().values().iterator().next()
+            .getFirst().items().getFirst().customName());
+        repository.save(loaded);
+        assertTrue(Files.readString(path).contains("custom-name: Archived List"));
+    }
+
+    @Test
+    void malformedOrUnavailableHistoricalItemDataFallsBackWithoutFailingLoad() throws Exception {
+        Path malformedPath = temporaryDirectory.resolve("malformed.yml");
+        writeHistoricalQuest(malformedPath, "not-base64%%% ");
+
+        Quest malformedQuest = new YamlQuestRepository(malformedPath).load()
+            .quests().values().iterator().next();
+
+        assertNull(malformedQuest.reward().getFirst().customName());
+        assertTrue(QuestListingFormatter.format(
+            malformedQuest, Instant.parse("2026-09-06T03:00:00Z")
+        ).contains("1 × PAPER (with exact item data)"));
+
+        Path unavailablePath = temporaryDirectory.resolve("unavailable.yml");
+        writeHistoricalQuest(unavailablePath, Base64.getEncoder().encodeToString(new byte[] {8}));
+        Quest unavailableQuest;
+        try (MockedStatic<ItemStack> itemStacks = Mockito.mockStatic(ItemStack.class)) {
+            itemStacks.when(() -> ItemStack.deserializeBytes(Mockito.any(byte[].class)))
+                .thenThrow(new IllegalStateException("server item codec unavailable"));
+            unavailableQuest = new YamlQuestRepository(unavailablePath).load()
+                .quests().values().iterator().next();
+        }
+        assertNull(unavailableQuest.reward().getFirst().customName());
+    }
+
     @Test
     void missingLifecycleStatusDefaultsToActiveForExistingYaml() throws Exception {
         Path path = temporaryDirectory.resolve("quests.yml");
@@ -93,6 +186,100 @@ final class YamlQuestRepositoryTest {
         assertTrue(Files.readString(path).contains("status: COMPLETED"));
     }
 
+    @Test
+    void roundTripsClaimsAndPendingNotificationsWhileOldFilesDefaultThemEmpty() throws Exception {
+        Path path = temporaryDirectory.resolve("quests.yml");
+        YamlQuestRepository repository = new YamlQuestRepository(path);
+        UUID issuer = UUID.randomUUID();
+        UUID questId = UUID.randomUUID();
+        Quest quest = new Quest(
+            questId, issuer, "Issuer", "STONE", 2,
+            List.of(new EscrowItem("DIAMOND", 1, null)),
+            Instant.parse("2026-09-05T03:00:00Z"),
+            Instant.parse("2026-09-12T03:00:00Z"), QuestStatus.COMPLETED
+        );
+        QuestClaim claim = new QuestClaim(
+            UUID.randomUUID(), questId, issuer,
+            List.of(new EscrowItem("STONE", 2, null)),
+            Instant.parse("2026-09-05T03:01:00Z")
+        );
+        IssuerNotification notification = new IssuerNotification(
+            UUID.randomUUID(), questId, issuer, "Your delivery can be claimed.",
+            Instant.parse("2026-09-05T03:01:00Z")
+        );
+        QuestState expected = new QuestState(
+            Map.of(questId, quest), Map.of(issuer, List.of(claim)),
+            Map.of(notification.id(), notification)
+        );
+
+        repository.save(expected);
+
+        assertEquals(expected, repository.load());
+        String yaml = Files.readString(path);
+        assertTrue(yaml.contains("claims:"));
+        assertTrue(yaml.contains("source: COMPLETION"));
+        assertTrue(yaml.contains("notifications:"));
+    }
+
+    @Test
+    void sourceLessHistoricalClaimsInferTypeFromQuestLifecycle() throws Exception {
+        Path path = temporaryDirectory.resolve("quests.yml");
+        Files.writeString(path, """
+            quests:
+            - id: 00000000-0000-0000-0000-000000000010
+              issuer-id: 00000000-0000-0000-0000-000000000001
+              issuer-name: Issuer
+              requested-material: STONE
+              requested-amount: 1
+              created-at: '2026-09-05T03:00:00Z'
+              expires-at: '2026-09-12T03:00:00Z'
+              status: CANCELLED
+              reward:
+              - material: DIAMOND
+                amount: 1
+            claims:
+            - id: 00000000-0000-0000-0000-000000000020
+              quest-id: 00000000-0000-0000-0000-000000000010
+              owner-id: 00000000-0000-0000-0000-000000000001
+              created-at: '2026-09-05T04:00:00Z'
+              items:
+              - material: DIAMOND
+                amount: 1
+            """);
+
+        QuestClaim claim = new YamlQuestRepository(path).load().claims().values()
+            .iterator().next().getFirst();
+
+        assertEquals(QuestClaimSource.CANCELLATION, claim.source());
+        assertEquals(QuestClaimType.RETURNED_REWARD, claim.type());
+    }
+
+    private static void writeHistoricalQuest(Path path, String itemData) throws IOException {
+        Files.writeString(path, """
+            quests:
+            - id: 00000000-0000-0000-0000-000000000010
+              issuer-id: 00000000-0000-0000-0000-000000000001
+              issuer-name: Issuer
+              requested-material: STONE
+              requested-amount: 1
+              created-at: '2026-09-05T03:00:00Z'
+              expires-at: '2026-09-12T03:00:00Z'
+              reward:
+              - material: PAPER
+                amount: 1
+                item-data: '%s'
+            claims:
+            - id: 00000000-0000-0000-0000-000000000020
+              quest-id: 00000000-0000-0000-0000-000000000010
+              owner-id: 00000000-0000-0000-0000-000000000001
+              created-at: '2026-09-05T04:00:00Z'
+              items:
+              - material: PAPER
+                amount: 1
+                item-data: '%s'
+            """.formatted(itemData, itemData));
+    }
+
     @Test
     void malformedStateIsRejectedRatherThanPartiallyLoaded() throws Exception {
         Path path = temporaryDirectory.resolve("quests.yml");