fix(board): make readable signs glow

README.md

@@ -6,7 +6,7 @@ The approved behavior is specified in the [OKF knowledge bundle](knowledge/index
 
 ## 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 compact native dashboard with dedicated browsing, creation, and claim screens. 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. Players can complete quests at any board or with `/quests complete <quest>` by delivering the required blocks. Exact escrowed rewards are granted immediately, and delivered blocks 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.
+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 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. Players can complete quests at any board or with `/quests complete <quest>` by delivering the required blocks. Exact escrowed rewards are granted immediately, and delivered blocks 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
 
@@ -40,6 +40,7 @@ The `spigotquestboard.admin` permission is granted to server operators by defaul
 
 ```text
 /questadmin createboard
+/questadmin createboard physical
 /questadmin commands <enable|disable>
 ```
 

knowledge/log.md

@@ -83,3 +83,25 @@ description: Chronological record of material decisions affecting Spigot Quest B
 - Split browsing, creation, and claims into dedicated native dialog screens with Back navigation.
 - Presented active quests as individual detail dialogs while retaining completion and issuer cancellation actions.
 - Verified 88 tests, including a 250-quest navigation case, and the plugin JAR with `./gradlew clean check jar`.
+
+## 2026-09-05 — Generated physical quest boards
+
+- Added `/questadmin createboard physical` to generate a five-wide, four-tall board above the targeted ground anchor facing the administrator.
+- Used oak-log pillars, an oak-plank face, and three oak wall signs with obfuscated decorative text.
+- Registered all visible planks and signs in one durable operation and added obstruction checks plus block rollback when construction or persistence fails.
+- Preserved existing single-block board creation and persisted board compatibility.
+- Verified 103 tests and the plugin JAR with `./gradlew clean check jar`.
+
+## 2026-09-05 — Readable physical-board signage
+
+- Added centered `Quest Board` and right-click instruction signs on the two layers above each generated board's three decorative signs.
+- Registered all five signs and the plank face as shared-board interaction locations.
+- Added exact legacy-structure detection and failure-safe startup upgrades for previously generated three-sign boards without touching custom or altered structures.
+- Verified 111 tests and the plugin JAR with `./gradlew clean check jar`.
+
+## 2026-09-05 — Glowing readable board signs
+
+- Enabled glowing front-side text on generated title and instruction signs while retaining non-glowing decorative signs.
+- Added exact full-structure detection to refresh existing generated boards once without modifying custom or altered signs.
+- Added two-sign snapshot rollback when a refresh cannot complete safely.
+- Verified 116 tests and the plugin JAR with `./gradlew clean check jar`.

knowledge/user-stories/index.md

@@ -16,3 +16,4 @@ description: Catalog of user stories for the Spigot Quest Board plugin.
 8. [US-008: Control player quest commands](us-008-control-player-quest-commands.md)
 9. [US-009: Use a screen-fitting quest-board interface](us-009-use-a-screen-fitting-quest-board-interface.md)
 10. [US-010: Generate a physical quest-board structure](us-010-generate-a-physical-quest-board.md)
+11. [US-011: Add readable physical-board signage](us-011-add-readable-physical-board-signage.md)

knowledge/user-stories/us-010-generate-a-physical-quest-board.md

@@ -2,7 +2,7 @@
 type: User Story
 title: "US-010: Generate a physical quest-board structure"
 description: Let an administrator generate and register a decorative oak quest board at a targeted ground anchor.
-status: backlog
+status: done
 ---
 
 # US-010: Generate a physical quest-board structure
@@ -11,17 +11,17 @@ As an **administrator**, I want quest-board creation to optionally construct a r
 
 ## Acceptance criteria
 
-- [ ] `/questadmin createboard physical` generates and registers a physical quest board while the existing `/questadmin createboard` behavior remains unchanged.
-- [ ] The targeted block is treated as the ground anchor and remains unchanged.
-- [ ] The generated board faces the administrator and is five blocks wide and four blocks tall.
-- [ ] The outer columns use oak-log pillars and the center uses oak planks.
-- [ ] Oak wall signs on the front display decorative obfuscated or gibberish text.
-- [ ] Clicking generated visible planks or signs opens the same globally shared quest-board interface.
-- [ ] Generation requires empty space and refuses to overwrite an existing structure.
-- [ ] Structure generation and interaction-location registration form one failure-safe transaction; failure restores changed blocks and registers nothing.
-- [ ] Generated interaction locations persist across restarts and remain compatible with existing registered boards.
-- [ ] The `physical` argument is offered through permission-aware command autocomplete.
-- [ ] Automated tests verify geometry, facing direction, obstruction handling, rollback, registration, persistence, and autocomplete.
+- [x] `/questadmin createboard physical` generates and registers a physical quest board while the existing `/questadmin createboard` behavior remains unchanged.
+- [x] The targeted block is treated as the ground anchor and remains unchanged.
+- [x] The generated board faces the administrator and is five blocks wide and four blocks tall.
+- [x] The outer columns use oak-log pillars and the center uses oak planks.
+- [x] Oak wall signs on the front display decorative obfuscated or gibberish text.
+- [x] Clicking generated visible planks or signs opens the same globally shared quest-board interface.
+- [x] Generation requires empty space and refuses to overwrite an existing structure.
+- [x] Structure generation and interaction-location registration form one failure-safe transaction; failure restores changed blocks and registers nothing.
+- [x] Generated interaction locations persist across restarts and remain compatible with existing registered boards.
+- [x] The `physical` argument is offered through permission-aware command autocomplete.
+- [x] Automated tests verify geometry, facing direction, obstruction handling, rollback, registration, persistence, and autocomplete.
 
 ## Related
 

knowledge/user-stories/us-011-add-readable-physical-board-signage.md

@@ -0,0 +1,28 @@
+---
+type: User Story
+title: "US-011: Add readable physical-board signage"
+description: Give generated quest boards a readable title and browsing instruction above their decorative signs.
+status: done
+---
+
+# US-011: Add readable physical-board signage
+
+As a **player**, I want readable signs on a generated quest board so that I know what it is and how to open it.
+
+## Acceptance criteria
+
+- [x] A generated physical board has a centered top sign reading `Quest Board` across its sign lines.
+- [x] A centered sign immediately below instructs the player to right-click a sign below to browse quests.
+- [x] The existing lower row retains three decorative signs with obfuscated or gibberish text.
+- [x] All five signs and the visible oak planks open the globally shared quest-board interface.
+- [x] New physical boards reserve and validate space for all five signs without overwriting blocks.
+- [x] Existing generated boards with the prior three-sign layout are detected from their exact registered oak structure and upgraded with the two centered readable signs.
+- [x] Existing custom single-block boards and unrelated structures are not modified.
+- [x] Existing-board upgrades never overwrite occupied sign locations and persist new interaction locations failure-safely.
+- [x] Automated tests verify sign placement, readable text, decorative text, interaction registration, obstruction handling, and prior-layout migration.
+- [x] The title and instruction signs use glowing front-side text for readability while decorative signs remain non-glowing.
+- [x] New boards receive glowing readable signs, and exact existing generated five-sign boards are refreshed on startup without modifying custom signs.
+
+## Related
+
+- [US-010: Generate a physical quest-board structure](us-010-generate-a-physical-quest-board.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/BoardRegistry.java

@@ -1,6 +1,7 @@
 package games.dmg.spigotquestboard;
 
 import java.io.IOException;
+import java.util.Collection;
 import java.util.LinkedHashMap;
 import java.util.Map;
 import java.util.Objects;
@@ -16,12 +17,22 @@ final class BoardRegistry {
     }
 
     synchronized BoardRegistrationResult register(RegisteredBoard board) throws IOException {
+        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);
+        for (RegisteredBoard board : additions) {
             Objects.requireNonNull(board, "board");
-        if (boards.containsKey(board.id())) {
+            if (candidate.putIfAbsent(board.id(), board) != null) {
                 return BoardRegistrationResult.ALREADY_REGISTERED;
             }
-        Map<BoardId, RegisteredBoard> candidate = new LinkedHashMap<>(boards);
-        candidate.put(board.id(), board);
+        }
+        if (additions.isEmpty()) {
+            return BoardRegistrationResult.CREATED;
+        }
         repository.save(new BoardState(Set.copyOf(candidate.values())));
         boards = Map.copyOf(candidate);
         return BoardRegistrationResult.CREATED;
@@ -35,6 +46,10 @@ final class BoardRegistry {
         return boards.size();
     }
 
+    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/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/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/QuestAdminCommand.java

@@ -15,10 +15,26 @@ 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, 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
@@ -32,13 +48,19 @@ final class QuestAdminCommand implements CommandExecutor, TabCompleter {
         if (arguments.length == 2 && "commands".equalsIgnoreCase(arguments[0])) {
             return updatePlayerCommands(sender, arguments[1]);
         }
-        if (arguments.length != 1 || !"createboard".equalsIgnoreCase(arguments[0])) {
-            sender.sendMessage(
-                "Usage: /questadmin createboard | /questadmin commands enable|disable"
-            );
+        if (arguments.length == 1 && "createboard".equalsIgnoreCase(arguments[0])) {
+            createBoard(sender);
             return true;
         }
-        createBoard(sender);
+        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;
     }
 
@@ -84,6 +106,36 @@ final class QuestAdminCommand implements CommandExecutor, TabCompleter {
         }
     }
 
+    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
@@ -97,6 +149,9 @@ final class QuestAdminCommand implements CommandExecutor, TabCompleter {
         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();
     }
 

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

@@ -13,10 +13,15 @@ public final class SpigotQuestBoardPlugin extends JavaPlugin {
         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")
             ));
@@ -69,10 +74,17 @@ public final class SpigotQuestBoardPlugin extends JavaPlugin {
         );
         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,

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)));

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/PhysicalBoardCreatorTest.java

@@ -0,0 +1,163 @@
+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")
+        ));
+    }
+
+    @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/PluginCommandWiringTest.java

@@ -1,5 +1,6 @@
 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;
@@ -8,12 +9,41 @@ 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.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 adminAndPlayerCommandsShareThePersistedSetting() throws Exception {
         PlayerCommandSettings settings = new PlayerCommandSettings(

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

@@ -12,7 +12,9 @@ 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;
@@ -126,9 +128,12 @@ final class QuestAdminCommandTest {
         assertEquals(List.of("disable"), executor.onTabComplete(
             authorized, command, "questadmin", new String[] {"commands", "di"}
         ));
-        assertTrue(executor.onTabComplete(
+        assertEquals(List.of("physical"), executor.onTabComplete(
             authorized, command, "questadmin", new String[] {"createboard", ""}
-        ).isEmpty());
+        ));
+        assertEquals(List.of("physical"), executor.onTabComplete(
+            authorized, command, "questadmin", new String[] {"createboard", "phy"}
+        ));
         assertTrue(executor.onTabComplete(
             unauthorized, command, "questadmin", new String[] {""}
         ).isEmpty());
@@ -161,6 +166,95 @@ 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();

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");