feat(pocket-base): allow return portal relocation

README.md

@@ -28,14 +28,24 @@ The plugin JAR is written to `build/libs/`.
 /basesettings (alias: /homesettings)
 /basesettings status
 /basesettings upgrade
+/basesettings pocket upgrade
+/basesettings pocket mobs <enable|disable>
 /basesettings visitors <allowed|blocked>
 /basesettings navigation <enable|disable>
 /basesettings flight <enable|disable>
+/basesettings border <enable|disable>
+/basesettings spawnable <enable|disable>
 /basesettings bossbar <enable|disable>
 ```
 
+Navigation particles appear only in the base's world and when the player is more than 25 blocks beyond the current base border.
+
+After 250 Survival-mode block placements anywhere by default, the spawnable overlay can mark nearby dark hostile-mob spawning surfaces inside the player's base with owner-only red particles. The threshold is configurable.
+
 `/base` has a stationary warm-up. Looking around is allowed, while movement between blocks, damage, teleportation, world changes, death, logout, and conflicting teleport commands cancel it without consuming the cooldown.
 
+Base IV owners can purchase and expand a persistent Pocket Base with `/basesettings pocket upgrade`. Activating a complete diamond-block portal frame inside the normal base with flint and steel opens one public entrance to the owner's grass platform in a private void world. The owner can move the return portal by building and igniting another complete frame inside the unlocked Pocket Base boundary; only the newly activated return portal remains functional. Natural hostile and passive mob spawning is disabled by default and can be controlled by the owner with `/basesettings pocket mobs <enable|disable>`.
+
 ## Administration
 
 The `spigotbase.admin` permission is granted to server operators by default. `/homeadmin` aliases `/baseadmin`.
@@ -43,8 +53,10 @@ The `spigotbase.admin` permission is granted to server operators by default. `/h
 ```text
 /baseadmin status <player>
 /baseadmin setlevel <player> <base|size|flight|warmup|cooldown> <level>
-/baseadmin setprogress <player> <grass_dirt|stone|deepslate|obsidian|placements|base_breaks> <amount>
+/baseadmin setprogress <player> <grass_dirt|stone|deepslate|obsidian|placements|total_placements|base_breaks> <amount>
+/baseadmin setsetting <player> spawnable <enable|disable>
 /baseadmin config <numeric-key> <value>
+# e.g. /baseadmin config spawnable-overlay-unlock-placements 250
 /baseadmin clearcooldown <player> [personal|visitor|all]
 /baseadmin reset <player> <size|flight|warmup|cooldown>
 /baseadmin reset <player> all confirm

design/log.md

@@ -69,3 +69,39 @@ description: Chronological record of material decisions affecting the Spigot Bas
 - Removed the unsafe unconfirmed base reset path; complete resets now require `reset <player> all confirm`.
 - Tightened argument validation and replaced implementation-specific enum errors with player-facing usage guidance.
 - Verified the administrative revision with `./gradlew clean check jar`.
+
+## 2026-08-10 — Base border visualization
+
+- Added persisted, owner-only base border particles controlled by `/basesettings border enable|disable` with contextual autocomplete.
+- Rendered a bounded nearby arc at the player's current height using the current base radius while respecting world and vertical bounds.
+- Added border preference reporting to player and administrative status output and safe defaults for existing state files.
+- Verified the feature with `./gradlew clean check jar`.
+
+## 2026-08-10 — Spawnable block overlay
+
+- Added persistent progression for Survival-mode block placements anywhere, with existing in-base placement counts used as a safe migration minimum.
+- Added `/basesettings spawnable enable|disable` after a configurable 250-placement unlock and reported its progress and preference in player and admin status output.
+- Added admin controls for total placement progress, the unlock threshold, and each unlocked player's overlay preference.
+- Added owner-only red particles for nearby dark spawning surfaces inside base bounds, using bounded incremental scanning and rendering budgets.
+- Verified the feature with `./gradlew clean check jar`.
+
+## 2026-08-10 — Navigation visibility buffer
+
+- Limited enabled base navigation particles to the base's world and positions more than 25 horizontal blocks beyond the current base border.
+- Used the live size-tier radius so expansion and relocation immediately update the visibility threshold.
+- Added exact-boundary and controller integration coverage.
+- Verified the change with `./gradlew clean check jar`.
+
+## 2026-08-24 — Pocket Base mob-spawning control
+
+- Disabled natural hostile and passive mob spawning by default in new and existing Pocket Bases without a saved preference.
+- Added the persisted owner setting `/basesettings pocket mobs enable|disable`, contextual autocomplete, and status reporting.
+- Reapplied saved spawn flags when Pocket Base worlds load and restored the prior world setting when persistence fails.
+- Verified the feature with `./gradlew clean check jar`.
+
+## 2026-08-24 — Relocatable Pocket Base return portals
+
+- Allowed Pocket Base owners to activate a complete return portal frame with flint and steel anywhere inside their unlocked pocket boundary.
+- Persisted one active return portal location while retaining the generated portal as the default for existing Pocket Bases.
+- Made only the selected intact frame functional without removing old frame blocks, preserving the void-return safety fallback.
+- Verified the feature with `./gradlew clean check jar`.

design/user-stories/index.md

@@ -18,3 +18,9 @@ description: Catalog of user stories for the Spigot Base plugin.
 10. [US-010: Administer player progression](us-010-administer-player-progression.md)
 11. [US-011: Configure and persist progression](us-011-configure-and-persist-progression.md)
 12. [US-012: Build and release the plugin](us-012-build-and-release-plugin.md)
+13. [US-013: Visualize the base border](us-013-visualize-base-border.md)
+14. [US-014: Highlight spawnable blocks](us-014-highlight-spawnable-blocks.md)
+15. [US-015: Unlock a Pocket Base](us-015-unlock-a-pocket-base.md)
+16. [US-016: Build and use Pocket Base portals](us-016-build-and-use-pocket-base-portals.md)
+17. [US-017: Expand a Pocket Base](us-017-expand-a-pocket-base.md)
+18. [US-018: Control Pocket Base mob spawning](us-018-control-pocket-base-mob-spawning.md)

design/user-stories/us-002-unlock-base-navigation.md

@@ -14,7 +14,9 @@ As a **player with Base I**, I want visual guidance toward my base so that I can
 - [x] Base II requires Base I and an established base.
 - [x] Base II unlocks at a configurable cumulative grass-or-dirt threshold that defaults to 500 blocks, 250 more than Base I.
 - [x] Base II provides particle-based navigation and does not grant or require a physical compass item.
-- [x] While enabled and in the base's world, particles are drawn along the ground to indicate the direction toward the base.
+- [x] While enabled and in the base's world, particles are drawn along the ground only when the player is horizontally more than 25 blocks beyond the current base border.
+- [x] No navigation particles appear inside the base, exactly 25 blocks beyond its border, or anywhere within that buffer.
+- [x] Expansion and relocation update the navigation visibility threshold immediately.
 - [x] Particle generation is bounded to avoid excessive server or client load.
 - [x] A player in another world receives a clear message instead of a misleading particle direction.
 - [x] `/basesettings navigation enable` enables guidance idempotently after Base II is unlocked, and `/basesettings navigation disable` disables it idempotently.

design/user-stories/us-004-unlock-and-control-base-flight.md

@@ -21,7 +21,7 @@ As a **player with Base I**, I want to unlock controlled flight around my base s
 - [x] Flight II expands the vertical range to 100 blocks below and above base Y by default.
 - [x] Flight III expands the vertical range to the world's minimum and maximum build heights.
 - [x] A configurable five-block horizontal warning buffer extends beyond the current base radius.
-- [x] Plugin-granted flight remains active in the warning buffer and displays prominent on-screen notice that the player is leaving the base.
+- [x] Plugin-granted flight remains active in the warning buffer, and a prominent on-screen notice that the player is leaving the base appears only while the player is actively flying.
 - [x] Passing beyond the warning buffer removes only flight granted by this plugin.
 - [x] Flight is not granted outside the unlocked vertical range.
 - [x] `/basesettings flight enable` enables unlocked flight idempotently, and `/basesettings flight disable` disables it idempotently.

design/user-stories/us-008-unlock-visitor-access.md

@@ -21,7 +21,8 @@ As a **player with Base III**, I want to open my base to visitors so that other
 - [x] `/gotobase <owner>` autocompletes bases that the requesting player is currently eligible to visit.
 - [x] `/visit <owner>` aliases `/gotobase <owner>` with identical autocomplete, including eligible bases whose owners are offline.
 - [x] Enabled bases remain visitable while their owners are offline.
-- [x] A visitor teleport uses the destination owner's current warm-up tier.
+- [x] `/visit` and `/gotobase` require the visitor to be in the destination base's recorded world; cross-dimension requests are rejected before warm-up with a clear message and without consuming cooldown.
+- [x] A visitor teleport uses the destination owner's current warm-up tier, but always requires at least a one-second stationary warm-up; `/visit` and `/gotobase` never teleport instantly.
 - [x] Looking around is permitted, while movement between block coordinates, damage, teleportation, world change, death, logout, or a conflicting teleport cancels the visitor warm-up.
 - [x] Cancellation or destination failure does not consume a visitor cooldown.
 - [x] A safe destination is resolved at or near the owner's recorded base center.
@@ -36,3 +37,5 @@ As a **player with Base III**, I want to open my base to visitors so that other
 - [US-005: Unlock Base III teleportation](us-005-unlock-base-teleportation.md)
 - [US-006: Reduce the base teleport warm-up](us-006-reduce-teleport-warmup.md)
 - [US-007: Reduce the base teleport cooldown](us-007-reduce-teleport-cooldown.md)
+- [US-015: Unlock a Pocket Base](us-015-unlock-a-pocket-base.md)
+- [US-016: Build and use Pocket Base portals](us-016-build-and-use-pocket-base-portals.md)

design/user-stories/us-013-visualize-base-border.md

@@ -0,0 +1,31 @@
+---
+type: User Story
+title: "US-013: Visualize the base border"
+description: Let players display a bounded, owner-only particle arc along the current edge of their established base.
+status: done
+---
+
+# US-013: Visualize the base border
+
+As a **player with Base I**, I want to display a particle effect at my base border so that I can understand where base benefits begin and end while building.
+
+## Acceptance criteria
+
+- [x] Border visualization requires Base I and an established base.
+- [x] `/basesettings border enable` enables visualization idempotently, and `/basesettings border disable` disables it idempotently.
+- [x] `border`, `enable`, and `disable` are offered through contextual autocomplete.
+- [x] Border visualization is disabled by default and the preference persists across reconnects and restarts.
+- [x] Older state files without the preference load it as disabled.
+- [x] `/basesettings status` and `/baseadmin status` display the border preference.
+- [x] Particles are visible only to the base owner.
+- [x] Particles trace the current circular horizontal boundary at the player's current Y-level and follow base expansion or relocation immediately.
+- [x] Particles render only while the player is in the base world, within the base's vertical range, and reasonably close to the boundary.
+- [x] Particle generation is bounded to avoid excessive server and client load.
+- [x] A complete administrative reset disables border visualization.
+
+## Related
+
+- [US-001: Unlock and establish Base I](us-001-unlock-and-establish-base.md)
+- [US-003: Expand the base](us-003-expand-the-base.md)
+- [US-009: View progression and unlock notifications](us-009-view-progression-and-notifications.md)
+- [US-010: Administer player progression](us-010-administer-player-progression.md)

design/user-stories/us-014-highlight-spawnable-blocks.md

@@ -0,0 +1,34 @@
+---
+type: User Story
+title: "US-014: Highlight spawnable blocks"
+description: Unlock an owner-only red particle overlay for nearby hostile-mob spawnable blocks after 250 placements anywhere.
+status: done
+---
+
+# US-014: Highlight spawnable blocks
+
+As a **player with an established base**, I want to highlight nearby blocks where hostile mobs can spawn so that I can find lighting gaps in my base.
+
+## Acceptance criteria
+
+- [x] Every block placed in Survival mode anywhere contributes to a persistent total-placement counter.
+- [x] The overlay unlocks permanently at a configurable 250 total placements by default.
+- [x] Existing players begin with at least their persisted in-base placement count because those placements are known to qualify.
+- [x] `/basesettings spawnable enable` enables the unlocked overlay idempotently, and `/basesettings spawnable disable` disables it idempotently.
+- [x] `spawnable`, `enable`, and `disable` are offered through contextual autocomplete.
+- [x] Enabling requires both the placement unlock and an established base; the persisted preference defaults to disabled.
+- [x] `/basesettings status` and `/baseadmin status` display placement progress, unlock state, and preference.
+- [x] Administrators can change a player's total-placement counter through `/baseadmin setprogress`.
+- [x] Administrators can persistently change the required placement threshold through `/baseadmin config spawnable-overlay-unlock-placements`.
+- [x] Administrators can enable or disable an unlocked player's overlay through `/baseadmin setsetting <player> spawnable <enable|disable>`.
+- [x] Owner-only red particles mark nearby candidate hostile-mob spawning surfaces inside the current base bounds.
+- [x] Candidate surfaces have block light zero, a solid spawning surface, and two passable blocks above them.
+- [x] Scanning is bounded to 16 horizontal blocks, eight vertical blocks, and a fixed per-update work and particle budget.
+- [x] A complete administrative reset clears total-placement progress and disables the overlay.
+
+## Related
+
+- [US-001: Unlock and establish Base I](us-001-unlock-and-establish-base.md)
+- [US-009: View progression and notifications](us-009-view-progression-and-notifications.md)
+- [US-010: Administer player progression](us-010-administer-player-progression.md)
+- [US-011: Configure and persist progression](us-011-configure-and-persist-progression.md)

design/user-stories/us-015-unlock-a-pocket-base.md

@@ -0,0 +1,30 @@
+---
+type: User Story
+title: "US-015: Unlock a Pocket Base"
+description: Let Base IV owners purchase a persistent private void world that serves as the foundation for portal access and expansion.
+status: done
+---
+
+# US-015: Unlock a Pocket Base
+
+As a **player with an established Base IV**, I want to unlock a persistent Pocket Base so that I can build in a personal space beyond the normal world.
+
+## Acceptance criteria
+
+- [x] Pocket Base progression requires an established Base IV.
+- [x] `/basesettings pocket upgrade` unlocks Pocket Base I and is offered through contextual autocomplete.
+- [x] Unlocking atomically charges a configurable currency and amount that default to 64 diamond blocks.
+- [x] Insufficient funds or failed persistence or world creation does not consume currency or grant Pocket Base I.
+- [x] Pocket Base I creates a persistent owner-specific void world keyed by the owner's UUID.
+- [x] The initial platform is 64 by 64 blocks with one grass layer over three dirt layers.
+- [x] The pocket world provides a safe arrival location and a generated return portal.
+- [x] Pocket Base worlds, contents, ownership, and progression persist through reconnects, restarts, and normal-base relocation.
+- [x] `/basesettings status` displays the current Pocket Base level and the next upgrade requirement.
+
+## Related
+
+- [US-008: Unlock Base IV visitor access](us-008-unlock-visitor-access.md)
+- [US-009: View progression and notifications](us-009-view-progression-and-notifications.md)
+- [US-011: Configure and persist progression](us-011-configure-and-persist-progression.md)
+- [US-016: Build and use Pocket Base portals](us-016-build-and-use-pocket-base-portals.md)
+- [US-017: Expand a Pocket Base](us-017-expand-a-pocket-base.md)

design/user-stories/us-016-build-and-use-pocket-base-portals.md

@@ -0,0 +1,40 @@
+---
+type: User Story
+title: "US-016: Build and use Pocket Base portals"
+description: Let an owner create one public portal between their normal base and persistent Pocket Base.
+status: done
+---
+
+# US-016: Build and use Pocket Base portals
+
+As a **Pocket Base owner**, I want to connect my normal base to my Pocket Base with a public portal so that I and other players can move between them naturally.
+
+## Acceptance criteria
+
+- [x] The entrance uses a standard 4-by-5 outer frame with a 2-by-3 interior and a configurable frame material that defaults to diamond blocks.
+- [x] Only the Pocket Base owner can activate a complete entrance frame with flint and steel.
+- [x] Every required frame block must be within the owner's current normal-base bounds when the entrance is activated.
+- [x] Custom particles and collision provide portal-like visuals and travel without relying on vanilla Nether portal blocks.
+- [x] Each owner has at most one active entrance portal.
+- [x] Activating another valid entrance deactivates the previous entrance without removing its frame blocks.
+- [x] Breaking any required frame block immediately deactivates the entrance.
+- [x] Any player can use an active entrance without a separate visitor setting, warm-up, or cooldown.
+- [x] Visitors can build, break blocks, open containers, and otherwise interact normally inside the Pocket Base.
+- [x] The generated return portal sends players safely to the owner's active entrance.
+- [x] Only the owner can activate a complete portal frame inside their own Pocket Base with flint and steel.
+- [x] Every required return-frame block must be within the owner's unlocked Pocket Base boundary.
+- [x] Each Pocket Base has at most one active return portal, and activating another valid frame moves the active return location without removing the old frame.
+- [x] Relocated return portals persist through restarts, while existing Pocket Bases use the generated portal as their default.
+- [x] Breaking the active return frame disables return travel through it.
+- [x] Return travel falls back to the server spawn when the owner has no valid normal-world entrance.
+- [x] Falling below Y -64 performs the same safe return without void damage.
+- [x] Players who disconnect inside a Pocket Base remain there when they reconnect.
+- [x] Moving the normal base deactivates its entrance while preserving the Pocket Base world and its contents.
+- [x] Portal ownership and the active entrance location persist through restarts.
+
+## Related
+
+- [US-003: Expand the base](us-003-expand-the-base.md)
+- [US-008: Unlock Base IV visitor access](us-008-unlock-visitor-access.md)
+- [US-015: Unlock a Pocket Base](us-015-unlock-a-pocket-base.md)
+- [US-017: Expand a Pocket Base](us-017-expand-a-pocket-base.md)

design/user-stories/us-017-expand-a-pocket-base.md

@@ -0,0 +1,28 @@
+---
+type: User Story
+title: "US-017: Expand a Pocket Base"
+description: Let Pocket Base owners purchase unlimited levels that add permanent buildable terrain around their pocket world.
+status: done
+---
+
+# US-017: Expand a Pocket Base
+
+As a **Pocket Base owner**, I want to purchase additional buildable space so that my pocket world can grow with my projects.
+
+## Acceptance criteria
+
+- [x] Using `/basesettings pocket upgrade` after Pocket Base I purchases the next Pocket Base level.
+- [x] Each additional level atomically charges a configurable currency and amount that default to 16 diamond blocks.
+- [x] Insufficient funds or failed persistence or terrain generation does not consume currency or grant a level.
+- [x] Each level adds 16 blocks on every side, producing Level I at 64 by 64, Level II at 96 by 96, Level III at 128 by 128, and size `64 + 32 × (level - 1)` thereafter.
+- [x] Newly unlocked terrain has one grass layer over three dirt layers.
+- [x] Expansion preserves all existing blocks, inventories, and entities in previously unlocked terrain.
+- [x] Owners and visitors cannot place blocks outside the currently unlocked horizontal boundary.
+- [x] Pocket Base progression has no plugin-configured level cap, subject only to Minecraft coordinate and integer limits.
+- [x] Pocket Base levels, dimensions, contents, and build boundaries persist through restarts.
+
+## Related
+
+- [US-011: Configure and persist progression](us-011-configure-and-persist-progression.md)
+- [US-015: Unlock a Pocket Base](us-015-unlock-a-pocket-base.md)
+- [US-016: Build and use Pocket Base portals](us-016-build-and-use-pocket-base-portals.md)

design/user-stories/us-018-control-pocket-base-mob-spawning.md

@@ -0,0 +1,28 @@
+---
+type: User Story
+title: "US-018: Control Pocket Base mob spawning"
+description: Let Pocket Base owners control natural mob spawning in their private world, with spawning disabled by default.
+status: done
+---
+
+# US-018: Control Pocket Base mob spawning
+
+As a **Pocket Base owner**, I want to enable or disable natural mob spawning in my Pocket Base so that I can choose whether the private world supports normal mob activity.
+
+## Acceptance criteria
+
+- [x] Natural mob spawning is disabled by default in every new Pocket Base and in existing Pocket Bases that have no saved preference.
+- [x] A Pocket Base owner can use `/basesettings pocket mobs enable|disable` to control natural mob spawning in their own Pocket Base.
+- [x] The setting controls both hostile and passive natural spawning only in the owner's Pocket Base.
+- [x] The command is unavailable until Pocket Base I is unlocked.
+- [x] The command and its modes are offered through contextual autocomplete.
+- [x] `/basesettings status` displays the current Pocket Base mob-spawning setting.
+- [x] The preference persists across restarts and is reapplied when the Pocket Base world loads.
+- [x] Disabling natural spawning does not remove existing mobs or prevent explicitly spawned or summoned mobs.
+- [x] Persistence or world-application failures produce a clear failure message without reporting a successful change.
+
+## Related
+
+- [US-015: Unlock a Pocket Base](us-015-unlock-a-pocket-base.md)
+- [US-016: Build and use Pocket Base portals](us-016-build-and-use-pocket-base-portals.md)
+- [US-017: Expand a Pocket Base](us-017-expand-a-pocket-base.md)

src/main/java/games/dmg/spigotbase/AdminProgressionService.java

@@ -92,6 +92,7 @@ public final class AdminProgressionService {
         long deepslate = player.deepslateBroken();
         long obsidian = player.obsidianBroken();
         long placements = player.blocksPlacedInBase();
+        long totalPlacements = player.totalBlocksPlaced();
         long baseBreaks = player.blocksBrokenInBase();
         switch (counter) {
             case GRASS_DIRT -> grassDirt = amount;
@@ -99,6 +100,7 @@ public final class AdminProgressionService {
             case DEEPSLATE -> deepslate = amount;
             case OBSIDIAN -> obsidian = amount;
             case PLACEMENTS -> placements = amount;
+            case TOTAL_PLACEMENTS -> totalPlacements = amount;
             case BASE_BREAKS -> baseBreaks = amount;
         }
         PluginSettings configured = settings.current();
@@ -147,7 +149,11 @@ public final class AdminProgressionService {
         }
         PlayerState updated = player.withProgressCounters(
             grassDirt, stone, deepslate, obsidian, placements, baseBreaks
-        );
+        ).withTotalBlocksPlaced(totalPlacements);
+        if (totalPlacements < configured.spawnableOverlayUnlockPlacements()
+                && updated.spawnableOverlayEnabled()) {
+            updated = updated.withSpawnableOverlayEnabled(false);
+        }
         return updated.withAdministrativeLevels(
             base,
             size,

src/main/java/games/dmg/spigotbase/BaseAdminCommand.java

@@ -16,14 +16,17 @@ import org.bukkit.plugin.java.JavaPlugin;
 
 final class BaseAdminCommand implements CommandExecutor, TabCompleter {
     private static final List<String> SUBCOMMANDS = List.of(
-        "status", "setlevel", "setprogress", "clearcooldown", "reset", "config"
+        "status", "setlevel", "setprogress", "setsetting", "clearcooldown", "reset", "config"
     );
     private static final List<String> PATHS = List.of(
         "base", "size", "flight", "warmup", "cooldown"
     );
     private static final List<String> COUNTERS = List.of(
-        "grass_dirt", "stone", "deepslate", "obsidian", "placements", "base_breaks"
+        "grass_dirt", "stone", "deepslate", "obsidian", "placements", "total_placements",
+        "base_breaks"
     );
+    private static final List<String> SETTINGS = List.of("spawnable");
+    private static final List<String> ENABLE_MODES = List.of("enable", "disable");
     private static final List<String> COOLDOWN_TYPES = List.of("personal", "visitor", "all");
     private static final List<String> RESET_PATHS = List.of(
         "size", "flight", "warmup", "cooldown", "all"
@@ -69,6 +72,7 @@ final class BaseAdminCommand implements CommandExecutor, TabCompleter {
             case "status" -> showProgress(sender, target.orElseThrow(), arguments);
             case "setlevel" -> setLevel(sender, target.orElseThrow(), arguments);
             case "setprogress" -> setProgress(sender, target.orElseThrow(), arguments);
+            case "setsetting" -> setSetting(sender, target.orElseThrow(), arguments);
             case "clearcooldown" -> clearCooldown(sender, target.orElseThrow(), arguments);
             case "reset" -> reset(sender, target.orElseThrow(), arguments);
             default -> {
@@ -94,11 +98,17 @@ final class BaseAdminCommand implements CommandExecutor, TabCompleter {
         sender.sendMessage(ChatColor.GRAY + "Grass/dirt=" + player.grassAndDirtBroken()
             + " stone=" + player.stoneBroken() + " deepslate=" + player.deepslateBroken()
             + " obsidian=" + player.obsidianBroken());
+        int spawnableThreshold = settingsProvider.current()
+            .spawnableOverlayUnlockPlacements();
         sender.sendMessage(ChatColor.GRAY + "In-base placements=" + player.blocksPlacedInBase()
+            + " total placements=" + player.totalBlocksPlaced()
             + " breaks=" + player.blocksBrokenInBase());
+        sender.sendMessage(ChatColor.GRAY + "Spawnable overlay="
+            + (player.totalBlocksPlaced() >= spawnableThreshold ? "unlocked" : "locked")
+            + " (" + player.totalBlocksPlaced() + "/" + spawnableThreshold + ")");
         sender.sendMessage(ChatColor.GRAY + "Toggles: navigation=" + player.navigationEnabled()
-            + " flight=" + player.flightEnabled() + " bossbar=" + player.bossBarEnabled()
-            + " visitors=" + player.visitorsEnabled());
+            + " flight=" + player.flightEnabled() + " border=" + player.borderEnabled()
+            + " spawnable=" + player.spawnableOverlayEnabled() + " bossbar=" + player.bossBarEnabled() + " visitors=" + player.visitorsEnabled());
         sender.sendMessage(ChatColor.GRAY + "Base: " + player.base()
             .map(base -> base.worldName() + " " + base.x() + "," + base.y() + "," + base.z())
             .orElse("not set"));
@@ -160,7 +170,8 @@ final class BaseAdminCommand implements CommandExecutor, TabCompleter {
         } catch (IllegalArgumentException exception) {
             sender.sendMessage(ChatColor.RED
                 + "Usage: /baseadmin setprogress <player> "
-                + "<grass_dirt|stone|deepslate|obsidian|placements|base_breaks> <amount>");
+                + "<grass_dirt|stone|deepslate|obsidian|placements|total_placements|base_breaks> "
+                + "<amount>");
             return true;
         }
         try {
@@ -181,6 +192,39 @@ final class BaseAdminCommand implements CommandExecutor, TabCompleter {
         return true;
     }
 
+    private boolean setSetting(
+        CommandSender sender,
+        PlayerState target,
+        String[] arguments
+    ) {
+        if (arguments.length != 4
+                || !arguments[2].equalsIgnoreCase("spawnable")
+                || !ENABLE_MODES.contains(arguments[3].toLowerCase(Locale.ROOT))) {
+            sender.sendMessage(ChatColor.RED + "Usage: /baseadmin setsetting <player> "
+                + "spawnable <enable|disable>");
+            return true;
+        }
+        boolean enabled = arguments[3].equalsIgnoreCase("enable");
+        if (enabled && target.totalBlocksPlaced()
+                < settingsProvider.current().spawnableOverlayUnlockPlacements()) {
+            sender.sendMessage(ChatColor.RED + "That player has not unlocked the spawnable overlay.");
+            return true;
+        }
+        if (enabled && (target.baseLevel() < 1 || target.base().isEmpty())) {
+            sender.sendMessage(ChatColor.RED + "That player does not have an established base.");
+            return true;
+        }
+        PlayerState updated = stateManager.update(
+            target.playerId(),
+            target.latestName(),
+            current -> current.withSpawnableOverlayEnabled(enabled)
+        );
+        stateManager.saveIfDirty();
+        sender.sendMessage(ChatColor.GREEN + "Set " + updated.latestName()
+            + "'s spawnable overlay to " + (enabled ? "enabled" : "disabled") + ".");
+        return true;
+    }
+
     private boolean clearCooldown(
         CommandSender sender,
         PlayerState target,
@@ -350,12 +394,16 @@ final class BaseAdminCommand implements CommandExecutor, TabCompleter {
             List<String> options = switch (arguments[0].toLowerCase(Locale.ROOT)) {
                 case "setlevel" -> PATHS;
                 case "setprogress" -> COUNTERS;
+                case "setsetting" -> SETTINGS;
                 case "clearcooldown" -> COOLDOWN_TYPES;
                 case "reset" -> RESET_PATHS;
                 default -> List.of();
             };
             return complete(options, arguments[2]);
         }
+        if (arguments.length == 4 && arguments[0].equalsIgnoreCase("setsetting")) {
+            return complete(ENABLE_MODES, arguments[3]);
+        }
         if (arguments.length == 4 && arguments[0].equalsIgnoreCase("setlevel")) {
             List<String> levels = switch (arguments[2].toLowerCase(Locale.ROOT)) {
                 case "base", "cooldown" -> LEVELS_FOUR;
@@ -386,7 +434,7 @@ final class BaseAdminCommand implements CommandExecutor, TabCompleter {
 
     private static void sendUsage(CommandSender sender) {
         sender.sendMessage(ChatColor.YELLOW + "Usage: /baseadmin "
-            + "<status|setlevel|setprogress|clearcooldown|reset> <player> ...");
+            + "<status|setlevel|setprogress|setsetting|clearcooldown|reset> <player> ...");
         sender.sendMessage(ChatColor.YELLOW + "       /baseadmin config <key> <integer>");
     }
 }

src/main/java/games/dmg/spigotbase/BaseBorderController.java

@@ -0,0 +1,62 @@
+package games.dmg.spigotbase;
+
+import org.bukkit.Location;
+import org.bukkit.Particle;
+import org.bukkit.Server;
+import org.bukkit.entity.Player;
+
+final class BaseBorderController implements Runnable {
+    private final Server server;
+    private final BaseStateManager stateManager;
+    private final BaseBoundsService boundsService;
+
+    BaseBorderController(
+        Server server,
+        BaseStateManager stateManager,
+        BaseBoundsService boundsService
+    ) {
+        this.server = server;
+        this.stateManager = stateManager;
+        this.boundsService = boundsService;
+    }
+
+    @Override
+    public void run() {
+        for (Player player : server.getOnlinePlayers()) {
+            PlayerState state = stateManager.player(player.getUniqueId(), player.getName());
+            if (!state.borderEnabled() || state.base().isEmpty()) {
+                continue;
+            }
+            BaseLocation base = state.base().orElseThrow();
+            if (!player.getWorld().getUID().equals(base.worldId())) {
+                continue;
+            }
+            Location playerLocation = player.getLocation();
+            long minimumY = (long) base.y() - boundsService.verticalRange(state);
+            long maximumY = (long) base.y() + boundsService.verticalRange(state);
+            if (playerLocation.getY() < minimumY || playerLocation.getY() > maximumY) {
+                continue;
+            }
+            for (BaseBorderGeometry.Point point : BaseBorderGeometry.visiblePoints(
+                    base.x() + 0.5,
+                    base.z() + 0.5,
+                    boundsService.radius(state),
+                    playerLocation.getX(),
+                    playerLocation.getZ()
+            )) {
+                Location particle = new Location(
+                    player.getWorld(),
+                    point.x(),
+                    playerLocation.getY() + 0.15,
+                    point.z()
+                );
+                player.spawnParticle(
+                    Particle.END_ROD,
+                    particle,
+                    1,
+                    0.0, 0.0, 0.0, 0.0
+                );
+            }
+        }
+    }
+}

src/main/java/games/dmg/spigotbase/BaseBorderGeometry.java

@@ -0,0 +1,58 @@
+package games.dmg.spigotbase;
+
+import java.util.ArrayList;
+import java.util.List;
+
+final class BaseBorderGeometry {
+    static final int MAX_PARTICLES = 64;
+    static final double VISIBILITY_DISTANCE = 32.0;
+    private static final double PARTICLE_SPACING = 1.0;
+
+    private BaseBorderGeometry() {
+    }
+
+    static List<Point> visiblePoints(
+        double centerX,
+        double centerZ,
+        int radius,
+        double playerX,
+        double playerZ
+    ) {
+        if (radius <= 0) {
+            throw new IllegalArgumentException("border radius must be positive");
+        }
+        double playerRadius = Math.hypot(playerX - centerX, playerZ - centerZ);
+        if (Math.abs(playerRadius - radius) > VISIBILITY_DISTANCE) {
+            return List.of();
+        }
+
+        double circumference = 2.0 * Math.PI * radius;
+        int count = Math.min(MAX_PARTICLES, Math.max(1, (int) Math.ceil(
+            circumference / PARTICLE_SPACING
+        )));
+        double centerAngle = Math.atan2(playerZ - centerZ, playerX - centerX);
+        double angleStep = circumference <= MAX_PARTICLES * PARTICLE_SPACING
+            ? 2.0 * Math.PI / count
+            : PARTICLE_SPACING / radius;
+        double startAngle = circumference <= MAX_PARTICLES * PARTICLE_SPACING
+            ? 0.0
+            : centerAngle - angleStep * (count - 1) / 2.0;
+
+        List<Point> points = new ArrayList<>(count);
+        double visibilitySquared = VISIBILITY_DISTANCE * VISIBILITY_DISTANCE;
+        for (int index = 0; index < count; index++) {
+            double angle = startAngle + angleStep * index;
+            double x = centerX + radius * Math.cos(angle);
+            double z = centerZ + radius * Math.sin(angle);
+            double deltaX = x - playerX;
+            double deltaZ = z - playerZ;
+            if (deltaX * deltaX + deltaZ * deltaZ <= visibilitySquared) {
+                points.add(new Point(x, z));
+            }
+        }
+        return List.copyOf(points);
+    }
+
+    record Point(double x, double z) {
+    }
+}

src/main/java/games/dmg/spigotbase/BaseFlightController.java

@@ -112,7 +112,7 @@ final class BaseFlightController implements Runnable {
             player.setAllowFlight(true);
             grantedFlight.add(player.getUniqueId());
         }
-        if (distanceSquared > (double) radius * radius) {
+        if (distanceSquared > (double) radius * radius && player.isFlying()) {
             if (warned.add(player.getUniqueId())) {
                 player.sendTitle(
                     ChatColor.RED + "Leaving Your Base",

src/main/java/games/dmg/spigotbase/BaseNavigationController.java

@@ -10,6 +10,7 @@ final class BaseNavigationController implements Runnable {
     private final Server server;
     private final BaseStateManager stateManager;
     private final PluginSettingsProvider settings;
+    private final BaseBoundsService boundsService;
 
     BaseNavigationController(
         Server server,
@@ -19,6 +20,7 @@ final class BaseNavigationController implements Runnable {
         this.server = server;
         this.stateManager = stateManager;
         this.settings = settings;
+        this.boundsService = new BaseBoundsService(settings);
     }
 
     @Override
@@ -32,7 +34,16 @@ final class BaseNavigationController implements Runnable {
             if (!player.getWorld().getUID().equals(base.worldId())) {
                 continue;
             }
-            Location origin = player.getLocation().clone().add(0.0, 0.15, 0.0);
+            Location playerLocation = player.getLocation();
+            if (!BaseNavigationVisibility.isBeyondBorderBuffer(
+                    base,
+                    boundsService.radius(state),
+                    playerLocation.getX(),
+                    playerLocation.getZ()
+            )) {
+                continue;
+            }
+            Location origin = playerLocation.clone().add(0.0, 0.15, 0.0);
             Vector direction = new Vector(
                 base.x() + 0.5 - origin.getX(),
                 0.0,

src/main/java/games/dmg/spigotbase/BaseNavigationVisibility.java

@@ -0,0 +1,26 @@
+package games.dmg.spigotbase;
+
+final class BaseNavigationVisibility {
+    static final int BORDER_BUFFER = 25;
+
+    private BaseNavigationVisibility() {
+    }
+
+    static boolean isBeyondBorderBuffer(
+        BaseLocation base,
+        int radius,
+        double playerX,
+        double playerZ
+    ) {
+        if (base == null) {
+            throw new IllegalArgumentException("base is required");
+        }
+        if (radius <= 0) {
+            throw new IllegalArgumentException("base radius must be positive");
+        }
+        double deltaX = playerX - (base.x() + 0.5);
+        double deltaZ = playerZ - (base.z() + 0.5);
+        double minimumDistance = radius + BORDER_BUFFER;
+        return deltaX * deltaX + deltaZ * deltaZ > minimumDistance * minimumDistance;
+    }
+}

src/main/java/games/dmg/spigotbase/BaseProgressListener.java

@@ -24,6 +24,7 @@ final class BaseProgressListener implements Listener {
     private final BaseProgressionService baseProgressionService;
     private final SecondaryProgressionService secondaryProgressionService;
     private final TeleportProgressionService teleportProgressionService;
+    private final SpawnableOverlayProgressionService spawnableOverlayProgressionService;
     private final BaseBoundsService boundsService;
     private final PluginSettingsProvider settings;
     private final Map<UUID, BossBar> activeBossBars = new HashMap<>();
@@ -34,6 +35,7 @@ final class BaseProgressListener implements Listener {
         BaseProgressionService baseProgressionService,
         SecondaryProgressionService secondaryProgressionService,
         TeleportProgressionService teleportProgressionService,
+        SpawnableOverlayProgressionService spawnableOverlayProgressionService,
         BaseBoundsService boundsService,
         PluginSettingsProvider settings
     ) {
@@ -42,6 +44,7 @@ final class BaseProgressListener implements Listener {
         this.baseProgressionService = baseProgressionService;
         this.secondaryProgressionService = secondaryProgressionService;
         this.teleportProgressionService = teleportProgressionService;
+        this.spawnableOverlayProgressionService = spawnableOverlayProgressionService;
         this.boundsService = boundsService;
         this.settings = settings;
     }
@@ -97,26 +100,43 @@ final class BaseProgressListener implements Listener {
             return;
         }
         PlayerState before = stateManager.player(player.getUniqueId(), player.getName());
-        if (!isInsideBase(
-                before,
-                event.getBlockPlaced().getWorld().getUID(),
-                event.getBlockPlaced().getX(),
-                event.getBlockPlaced().getY(),
-                event.getBlockPlaced().getZ())) {
-            return;
-        }
+        boolean insideBase = isInsideBase(
+            before,
+            event.getBlockPlaced().getWorld().getUID(),
+            event.getBlockPlaced().getX(),
+            event.getBlockPlaced().getY(),
+            event.getBlockPlaced().getZ()
+        );
         ProgressionUpdate[] updateHolder = new ProgressionUpdate[1];
+        SpawnableOverlayProgressionUpdate[] overlayHolder =
+            new SpawnableOverlayProgressionUpdate[1];
         PlayerState state = stateManager.update(player.getUniqueId(), player.getName(), current -> {
-            ProgressionUpdate update = teleportProgressionService.recordPlacement(current);
+            SpawnableOverlayProgressionUpdate overlay =
+                spawnableOverlayProgressionService.recordPlacement(current);
+            ProgressionUpdate update = insideBase
+                ? teleportProgressionService.recordPlacement(overlay.player())
+                : ProgressionUpdate.unchanged(overlay.player());
+            overlayHolder[0] = overlay;
             updateHolder[0] = update;
             return update.player();
         });
         ProgressionUpdate update = updateHolder[0];
+        SpawnableOverlayProgressionUpdate overlay = overlayHolder[0];
         announceUnlock(player, update);
-        if (hasUnlock(update)) {
+        if (overlay.unlocked()) {
+            sendUnlockTitle(
+                player,
+                ChatColor.GOLD + "Spawnable Overlay Unlocked",
+                ChatColor.YELLOW + "/basesettings spawnable enable is now available"
+            );
+            player.sendMessage(ChatColor.GREEN
+                + "You unlocked spawnable block highlighting! Use "
+                + "/basesettings spawnable enable.");
+        }
+        if (hasUnlock(update) || overlay.unlocked()) {
             stateManager.saveIfDirty();
         }
-        if (state.bossBarEnabled() && state.baseLevel() >= 2) {
+        if (insideBase && state.bossBarEnabled() && state.baseLevel() >= 2) {
             showProgress(player, warmupDisplay(state));
         }
     }

src/main/java/games/dmg/spigotbase/BaseSettingsCommand.java

@@ -15,7 +15,8 @@ import org.bukkit.inventory.PlayerInventory;
 
 final class BaseSettingsCommand implements CommandExecutor, TabCompleter {
     private static final List<String> SETTINGS = List.of(
-        "status", "upgrade", "visitors", "navigation", "flight", "bossbar"
+        "status", "upgrade", "pocket", "visitors", "navigation", "flight", "border",
+        "spawnable", "bossbar"
     );
     private static final List<String> VISITOR_MODES = List.of("allowed", "blocked");
     private static final List<String> ENABLE_MODES = List.of("enable", "disable");
@@ -23,16 +24,27 @@ final class BaseSettingsCommand implements CommandExecutor, TabCompleter {
     private final PluginSettingsProvider settings;
     private final TeleportPolicy teleportPolicy;
     private final BaseFlightController flightController;
+    private final PocketBaseManager pocketBases;
 
     BaseSettingsCommand(
         BaseStateManager stateManager,
         PluginSettingsProvider settings,
         BaseFlightController flightController
+    ) {
+        this(stateManager, settings, flightController, null);
+    }
+
+    BaseSettingsCommand(
+        BaseStateManager stateManager,
+        PluginSettingsProvider settings,
+        BaseFlightController flightController,
+        PocketBaseManager pocketBases
     ) {
         this.stateManager = stateManager;
         this.settings = settings;
         this.teleportPolicy = new TeleportPolicy(settings);
         this.flightController = flightController;
+        this.pocketBases = pocketBases;
     }
 
     @Override
@@ -50,6 +62,14 @@ final class BaseSettingsCommand implements CommandExecutor, TabCompleter {
         if (arguments.length == 1 && arguments[0].equalsIgnoreCase("upgrade")) {
             return purchaseVisitorAccess(player, state);
         }
+        if (arguments.length == 2 && arguments[0].equalsIgnoreCase("pocket")
+                && arguments[1].equalsIgnoreCase("upgrade")) {
+            return purchasePocketUpgrade(player, state);
+        }
+        if (arguments.length == 3 && arguments[0].equalsIgnoreCase("pocket")
+                && arguments[1].equalsIgnoreCase("mobs")) {
+            return updatePocketMobSpawning(player, arguments[2]);
+        }
         if (arguments.length == 2 && arguments[0].equalsIgnoreCase("visitors")) {
             return updateVisitors(player, state, arguments[1]);
         }
@@ -59,6 +79,12 @@ final class BaseSettingsCommand implements CommandExecutor, TabCompleter {
         if (arguments.length == 2 && arguments[0].equalsIgnoreCase("flight")) {
             return updateFlight(player, state, arguments[1]);
         }
+        if (arguments.length == 2 && arguments[0].equalsIgnoreCase("border")) {
+            return updateBorder(player, state, arguments[1]);
+        }
+        if (arguments.length == 2 && arguments[0].equalsIgnoreCase("spawnable")) {
+            return updateSpawnableOverlay(player, state, arguments[1]);
+        }
         if (arguments.length == 2 && arguments[0].equalsIgnoreCase("bossbar")) {
             return updateBossBar(player, arguments[1]);
         }
@@ -107,6 +133,84 @@ final class BaseSettingsCommand implements CommandExecutor, TabCompleter {
         return true;
     }
 
+    private boolean purchasePocketUpgrade(Player player, PlayerState owner) {
+        if (pocketBases == null) {
+            player.sendMessage(ChatColor.RED + "Pocket Bases are currently unavailable.");
+            return true;
+        }
+        if (owner.baseLevel() < 4 || owner.base().isEmpty()) {
+            player.sendMessage(ChatColor.RED
+                + "Establish Base IV before purchasing a Pocket Base.");
+            return true;
+        }
+        PocketBaseState current = pocketBases.state(owner.playerId());
+        int price = current.level() == 0
+            ? settings.current().pocketBaseUnlockCost()
+            : settings.current().pocketBaseUpgradeCost();
+        Material currency = Material.valueOf(settings.current().pocketBaseCurrencyMaterial());
+        PlayerInventory inventory = player.getInventory();
+        if (countCurrency(inventory, currency) < price) {
+            player.sendMessage(ChatColor.RED + "Pocket Base "
+                + (current.level() == 0 ? "I" : "level " + (current.level() + 1))
+                + " costs " + price + " "
+                + currency.name().toLowerCase(java.util.Locale.ROOT) + ".");
+            return true;
+        }
+        ItemStack[] snapshot = cloneContents(inventory.getStorageContents());
+        removeCurrency(inventory, currency, price);
+        final PocketBaseState upgraded;
+        try {
+            upgraded = pocketBases.upgrade(owner.playerId());
+        } catch (IOException | RuntimeException exception) {
+            inventory.setStorageContents(snapshot);
+            player.sendMessage(ChatColor.RED
+                + "The Pocket Base upgrade failed; your payment was restored.");
+            return true;
+        }
+        player.sendTitle(
+            ChatColor.GOLD + "Pocket Base " + upgraded.level() + " Unlocked",
+            ChatColor.YELLOW + "Build a portal inside your base",
+            settings.current().titleFadeInTicks(),
+            settings.current().titleStayTicks(),
+            settings.current().titleFadeOutTicks()
+        );
+        player.sendMessage(ChatColor.GREEN + "Pocket Base level " + upgraded.level()
+            + " unlocked for " + price + " "
+            + currency.name().toLowerCase(java.util.Locale.ROOT) + ".");
+        return true;
+    }
+
+    private boolean updatePocketMobSpawning(Player player, String mode) {
+        if (pocketBases == null) {
+            player.sendMessage(ChatColor.RED + "Pocket Bases are currently unavailable.");
+            return true;
+        }
+        PocketBaseState current = pocketBases.state(player.getUniqueId());
+        if (current.level() < 1) {
+            player.sendMessage(ChatColor.RED + "Pocket Base I is still locked.");
+            return true;
+        }
+        Boolean enabled = enabledMode(mode);
+        if (enabled == null) {
+            sendUsage(player);
+            return true;
+        }
+        final PocketBaseState updated;
+        try {
+            updated = pocketBases.setMobSpawning(player.getUniqueId(), enabled);
+        } catch (IOException | RuntimeException exception) {
+            player.sendMessage(ChatColor.RED
+                + "The Pocket Base mob-spawning setting could not be changed.");
+            return true;
+        }
+        player.sendMessage(ChatColor.YELLOW + "Pocket Base mob spawning is now "
+            + (updated.mobSpawningEnabled()
+                ? ChatColor.GREEN + "enabled"
+                : ChatColor.RED + "disabled")
+            + ChatColor.YELLOW + ".");
+        return true;
+    }
+
     private boolean updateVisitors(Player player, PlayerState state, String mode) {
         if (state.baseLevel() < 4) {
             player.sendMessage(ChatColor.RED + "Base IV visitor access is still locked.");
@@ -189,6 +293,59 @@ final class BaseSettingsCommand implements CommandExecutor, TabCompleter {
         return true;
     }
 
+    private boolean updateBorder(Player player, PlayerState state, String mode) {
+        if (state.baseLevel() < 1 || state.base().isEmpty()) {
+            player.sendMessage(ChatColor.RED
+                + "Establish Base I before enabling border visualization.");
+            return true;
+        }
+        Boolean enabled = enabledMode(mode);
+        if (enabled == null) {
+            sendUsage(player);
+            return true;
+        }
+        state = stateManager.update(
+            player.getUniqueId(),
+            player.getName(),
+            current -> current.withBorderEnabled(enabled)
+        );
+        stateManager.saveIfDirty();
+        player.sendMessage(ChatColor.YELLOW + "Base border visualization is now "
+            + (state.borderEnabled() ? ChatColor.GREEN + "enabled" : ChatColor.RED + "disabled")
+            + ChatColor.YELLOW + ".");
+        return true;
+    }
+
+    private boolean updateSpawnableOverlay(Player player, PlayerState state, String mode) {
+        if (state.totalBlocksPlaced() < settings.current().spawnableOverlayUnlockPlacements()) {
+            player.sendMessage(ChatColor.RED + "Spawnable highlighting unlocks after "
+                + settings.current().spawnableOverlayUnlockPlacements() + " total placements.");
+            return true;
+        }
+        if (state.baseLevel() < 1 || state.base().isEmpty()) {
+            player.sendMessage(ChatColor.RED
+                + "Establish Base I before enabling spawnable highlighting.");
+            return true;
+        }
+        Boolean enabled = enabledMode(mode);
+        if (enabled == null) {
+            sendUsage(player);
+            return true;
+        }
+        state = stateManager.update(
+            player.getUniqueId(),
+            player.getName(),
+            current -> current.withSpawnableOverlayEnabled(enabled)
+        );
+        stateManager.saveIfDirty();
+        player.sendMessage(ChatColor.YELLOW + "Spawnable block highlighting is now "
+            + (state.spawnableOverlayEnabled()
+                ? ChatColor.GREEN + "enabled"
+                : ChatColor.RED + "disabled")
+            + ChatColor.YELLOW + ".");
+        return true;
+    }
+
     private boolean updateBossBar(Player player, String mode) {
         Boolean enabled = enabledMode(mode);
         if (enabled == null) {
@@ -214,10 +371,18 @@ final class BaseSettingsCommand implements CommandExecutor, TabCompleter {
         showFlightPath(player, state);
         showWarmupPath(player, state);
         showCooldownPath(player, state);
+        showPocketPath(player, state);
+        int spawnableThreshold = settings.current().spawnableOverlayUnlockPlacements();
+        player.sendMessage(ChatColor.YELLOW + "Spawnable Overlay: " + ChatColor.GRAY
+            + state.totalBlocksPlaced() + "/" + spawnableThreshold + " placements; "
+            + (state.totalBlocksPlaced() >= spawnableThreshold ? "unlocked" : "locked")
+            + "; setting=" + (state.spawnableOverlayEnabled() ? "enabled" : "disabled"));
         player.sendMessage(ChatColor.GRAY + "Settings: visitors="
             + (state.visitorsEnabled() ? "allowed" : "blocked")
             + " navigation=" + (state.navigationEnabled() ? "enabled" : "disabled")
             + " flight=" + (state.flightEnabled() ? "enabled" : "disabled")
+            + " border=" + (state.borderEnabled() ? "enabled" : "disabled")
+            + " spawnable=" + (state.spawnableOverlayEnabled() ? "enabled" : "disabled")
             + " bossbar=" + (state.bossBarEnabled() ? "enabled" : "disabled"));
         state.base().ifPresentOrElse(
             base -> player.sendMessage(ChatColor.GRAY + "Base: " + base.worldName() + " "
@@ -277,6 +442,20 @@ final class BaseSettingsCommand implements CommandExecutor, TabCompleter {
             + DurationFormatter.friendly(teleportPolicy.warmup(state)) + "; " + detail);
     }
 
+    private void showPocketPath(Player player, PlayerState owner) {
+        PocketBaseState pocket = pocketBases == null
+            ? PocketBaseState.locked(owner.playerId())
+            : pocketBases.state(owner.playerId());
+        int price = pocket.level() == 0
+            ? settings.current().pocketBaseUnlockCost()
+            : settings.current().pocketBaseUpgradeCost();
+        player.sendMessage(colorForPrerequisite(owner.baseLevel() >= 4 && owner.base().isPresent())
+            + "Pocket Base " + pocket.level() + ": " + ChatColor.GRAY + price + " "
+            + settings.current().pocketBaseCurrencyMaterial().toLowerCase(Locale.ROOT)
+            + " → /basesettings pocket upgrade; mob spawning="
+            + (pocket.mobSpawningEnabled() ? "enabled" : "disabled"));
+    }
+
     private void showCooldownPath(Player player, PlayerState state) {
         String detail = switch (state.cooldownLevel()) {
             case 0 -> state.blocksBrokenInBase() + "/" + settings.current().firstCooldownBreaks();
@@ -306,12 +485,18 @@ final class BaseSettingsCommand implements CommandExecutor, TabCompleter {
             List<String> modes = arguments[0].equalsIgnoreCase("visitors")
                 ? VISITOR_MODES
                 : switch (arguments[0].toLowerCase(Locale.ROOT)) {
-                    case "navigation", "flight", "bossbar" -> ENABLE_MODES;
+                    case "pocket" -> List.of("upgrade", "mobs");
+                    case "navigation", "flight", "border", "spawnable", "bossbar" -> ENABLE_MODES;
                     default -> List.of();
                 };
             String prefix = arguments[1].toLowerCase(Locale.ROOT);
             return modes.stream().filter(mode -> mode.startsWith(prefix)).toList();
         }
+        if (arguments.length == 3 && arguments[0].equalsIgnoreCase("pocket")
+                && arguments[1].equalsIgnoreCase("mobs")) {
+            String prefix = arguments[2].toLowerCase(Locale.ROOT);
+            return ENABLE_MODES.stream().filter(mode -> mode.startsWith(prefix)).toList();
+        }
         return List.of();
     }
 
@@ -371,7 +556,9 @@ final class BaseSettingsCommand implements CommandExecutor, TabCompleter {
 
     private static void sendUsage(Player player) {
         player.sendMessage(ChatColor.RED + "Usage: /basesettings "
-            + "[status|upgrade|visitors <allowed|blocked>|navigation <enable|disable>"
-            + "|flight <enable|disable>|bossbar <enable|disable>]");
+            + "[status|upgrade|pocket upgrade|pocket mobs <enable|disable>"
+            + "|visitors <allowed|blocked>|navigation <enable|disable>"
+            + "|flight <enable|disable>|border <enable|disable>"
+            + "|spawnable <enable|disable>|bossbar <enable|disable>]");
     }
 }

src/main/java/games/dmg/spigotbase/BaseTeleportManager.java

@@ -83,6 +83,13 @@ final class BaseTeleportManager implements Listener {
             visitor.sendMessage(ChatColor.RED + "That base is not accepting visitors.");
             return;
         }
+        BaseLocation destination = owner.base().orElseThrow();
+        if (!visitor.getWorld().getUID().equals(destination.worldId())) {
+            visitor.sendMessage(
+                ChatColor.RED + "You must be in the same dimension as that base to visit it."
+            );
+            return;
+        }
         PlayerState visitorState = stateManager.player(visitor.getUniqueId(), visitor.getName());
         Optional<Duration> remaining = visitorPolicy.remaining(
             visitorState, owner.playerId(), clock.instant()
@@ -94,8 +101,8 @@ final class BaseTeleportManager implements Listener {
         }
         begin(
             visitor,
-            owner.base().orElseThrow(),
-            policy.warmup(owner),
+            destination,
+            policy.visitorWarmup(owner),
             owner.playerId(),
             policy.cooldown(owner),
             "visit " + owner.latestName() + "'s base"

src/main/java/games/dmg/spigotbase/BlockPosition.java

@@ -0,0 +1,4 @@
+package games.dmg.spigotbase;
+
+public record BlockPosition(int x, int y, int z) {
+}

src/main/java/games/dmg/spigotbase/PlayerState.java

@@ -26,7 +26,10 @@ public record PlayerState(
     boolean visitorsEnabled,
     Optional<Instant> lastBaseSet,
     Optional<Instant> lastBaseTeleport,
-    Map<UUID, Instant> visitorCooldownUntil
+    Map<UUID, Instant> visitorCooldownUntil,
+    boolean borderEnabled,
+    long totalBlocksPlaced,
+    boolean spawnableOverlayEnabled
 ) {
     public PlayerState {
         if (playerId == null) {
@@ -53,6 +56,7 @@ public record PlayerState(
         requireNonNegative(obsidianBroken, "obsidian broken");
         requireNonNegative(blocksPlacedInBase, "blocks placed in base");
         requireNonNegative(blocksBrokenInBase, "blocks broken in base");
+        requireNonNegative(totalBlocksPlaced, "total blocks placed");
 
         if (baseLevel == 0 && (sizeLevel > 0 || flightLevel > 0)) {
             throw new IllegalArgumentException("secondary progression requires Base I");
@@ -69,12 +73,83 @@ public record PlayerState(
         if (baseLevel < 4 && visitorsEnabled) {
             throw new IllegalArgumentException("visitor access requires Base IV");
         }
+        if (borderEnabled && (baseLevel < 1 || base.isEmpty())) {
+            throw new IllegalArgumentException("border visualization requires an established Base I");
+        }
+        if (spawnableOverlayEnabled && (baseLevel < 1 || base.isEmpty())) {
+            throw new IllegalArgumentException("spawnable overlay requires an established Base I");
+        }
         if (visitorCooldownUntil.entrySet().stream().anyMatch(entry ->
                 entry.getKey() == null || entry.getValue() == null)) {
             throw new IllegalArgumentException("visitor cooldowns must be complete");
         }
     }
 
+    public PlayerState(
+        UUID playerId,
+        String latestName,
+        Optional<BaseLocation> base,
+        int baseLevel,
+        int sizeLevel,
+        int flightLevel,
+        int warmupLevel,
+        int cooldownLevel,
+        long grassAndDirtBroken,
+        long stoneBroken,
+        long deepslateBroken,
+        long obsidianBroken,
+        long blocksPlacedInBase,
+        long blocksBrokenInBase,
+        boolean navigationEnabled,
+        boolean flightEnabled,
+        boolean bossBarEnabled,
+        boolean visitorsEnabled,
+        Optional<Instant> lastBaseSet,
+        Optional<Instant> lastBaseTeleport,
+        Map<UUID, Instant> visitorCooldownUntil
+    ) {
+        this(
+            playerId, latestName, base, baseLevel, sizeLevel, flightLevel,
+            warmupLevel, cooldownLevel, grassAndDirtBroken, stoneBroken, deepslateBroken,
+            obsidianBroken, blocksPlacedInBase, blocksBrokenInBase,
+            navigationEnabled, flightEnabled, bossBarEnabled, visitorsEnabled,
+            lastBaseSet, lastBaseTeleport, visitorCooldownUntil, false, 0, false
+        );
+    }
+
+    public PlayerState(
+        UUID playerId,
+        String latestName,
+        Optional<BaseLocation> base,
+        int baseLevel,
+        int sizeLevel,
+        int flightLevel,
+        int warmupLevel,
+        int cooldownLevel,
+        long grassAndDirtBroken,
+        long stoneBroken,
+        long deepslateBroken,
+        long obsidianBroken,
+        long blocksPlacedInBase,
+        long blocksBrokenInBase,
+        boolean navigationEnabled,
+        boolean flightEnabled,
+        boolean bossBarEnabled,
+        boolean visitorsEnabled,
+        Optional<Instant> lastBaseSet,
+        Optional<Instant> lastBaseTeleport,
+        Map<UUID, Instant> visitorCooldownUntil,
+        boolean borderEnabled
+    ) {
+        this(
+            playerId, latestName, base, baseLevel, sizeLevel, flightLevel,
+            warmupLevel, cooldownLevel, grassAndDirtBroken, stoneBroken, deepslateBroken,
+            obsidianBroken, blocksPlacedInBase, blocksBrokenInBase,
+            navigationEnabled, flightEnabled, bossBarEnabled, visitorsEnabled,
+            lastBaseSet, lastBaseTeleport, visitorCooldownUntil, borderEnabled, 0, false
+        );
+    }
+
     public static PlayerState newPlayer(UUID playerId, String latestName) {
         return new PlayerState(
             playerId,
@@ -93,7 +168,8 @@ public record PlayerState(
             warmupLevel, cooldownLevel, grassAndDirtBroken, stoneBroken, deepslateBroken,
             obsidianBroken, blocksPlacedInBase, blocksBrokenInBase,
             navigationEnabled, flightEnabled, bossBarEnabled, visitorsEnabled,
-            lastBaseSet, lastBaseTeleport, visitorCooldownUntil
+            lastBaseSet, lastBaseTeleport, visitorCooldownUntil, borderEnabled,
+            totalBlocksPlaced, spawnableOverlayEnabled
         );
     }
 
@@ -103,7 +179,8 @@ public record PlayerState(
             warmupLevel, cooldownLevel, count, stoneBroken, deepslateBroken,
             obsidianBroken, blocksPlacedInBase, blocksBrokenInBase,
             navigationEnabled, flightEnabled, bossBarEnabled, visitorsEnabled,
-            lastBaseSet, lastBaseTeleport, visitorCooldownUntil
+            lastBaseSet, lastBaseTeleport, visitorCooldownUntil, borderEnabled,
+            totalBlocksPlaced, spawnableOverlayEnabled
         );
     }
 
@@ -113,7 +190,8 @@ public record PlayerState(
             warmupLevel, cooldownLevel, grassAndDirtBroken, stoneBroken, deepslateBroken,
             obsidianBroken, blocksPlacedInBase, blocksBrokenInBase,
             navigationEnabled, flightEnabled, enabled, visitorsEnabled,
-            lastBaseSet, lastBaseTeleport, visitorCooldownUntil
+            lastBaseSet, lastBaseTeleport, visitorCooldownUntil, borderEnabled,
+            totalBlocksPlaced, spawnableOverlayEnabled
         );
     }
 
@@ -123,7 +201,8 @@ public record PlayerState(
             warmupLevel, cooldownLevel, grassAndDirtBroken, stoneBroken, deepslateBroken,
             obsidianBroken, blocksPlacedInBase, blocksBrokenInBase,
             enabled, flightEnabled, bossBarEnabled, visitorsEnabled,
-            lastBaseSet, lastBaseTeleport, visitorCooldownUntil
+            lastBaseSet, lastBaseTeleport, visitorCooldownUntil, borderEnabled,
+            totalBlocksPlaced, spawnableOverlayEnabled
         );
     }
 
@@ -133,7 +212,8 @@ public record PlayerState(
             warmupLevel, cooldownLevel, grassAndDirtBroken, stone, deepslate,
             obsidian, blocksPlacedInBase, blocksBrokenInBase,
             navigationEnabled, flightEnabled, bossBarEnabled, visitorsEnabled,
-            lastBaseSet, lastBaseTeleport, visitorCooldownUntil
+            lastBaseSet, lastBaseTeleport, visitorCooldownUntil, borderEnabled,
+            totalBlocksPlaced, spawnableOverlayEnabled
         );
     }
 
@@ -143,7 +223,8 @@ public record PlayerState(
             warmupLevel, cooldownLevel, grassAndDirtBroken, stoneBroken, deepslateBroken,
             obsidianBroken, blocksPlacedInBase, blocksBrokenInBase,
             navigationEnabled, enabled, bossBarEnabled, visitorsEnabled,
-            lastBaseSet, lastBaseTeleport, visitorCooldownUntil
+            lastBaseSet, lastBaseTeleport, visitorCooldownUntil, borderEnabled,
+            totalBlocksPlaced, spawnableOverlayEnabled
         );
     }
 
@@ -163,7 +244,8 @@ public record PlayerState(
             newWarmupLevel, newCooldownLevel, grassAndDirtBroken, stoneBroken, deepslateBroken,
             obsidianBroken, placements, breaks,
             navigationEnabled, flightEnabled, bossBarEnabled, visitorsEnabled,
-            lastBaseSet, lastBaseTeleport, visitorCooldownUntil
+            lastBaseSet, lastBaseTeleport, visitorCooldownUntil, borderEnabled,
+            totalBlocksPlaced, spawnableOverlayEnabled
         );
     }
 
@@ -179,7 +261,8 @@ public record PlayerState(
             warmupLevel, cooldownLevel, grassAndDirtBroken, stoneBroken, deepslateBroken,
             obsidianBroken, blocksPlacedInBase, blocksBrokenInBase,
             navigationEnabled, flightEnabled, bossBarEnabled, visitorsEnabled,
-            lastBaseSet, Optional.of(usedAt), visitorCooldownUntil
+            lastBaseSet, Optional.of(usedAt), visitorCooldownUntil, borderEnabled,
+            totalBlocksPlaced, spawnableOverlayEnabled
         );
     }
 
@@ -189,7 +272,8 @@ public record PlayerState(
             warmupLevel, cooldownLevel, grassAndDirtBroken, stoneBroken, deepslateBroken,
             obsidianBroken, blocksPlacedInBase, blocksBrokenInBase,
             navigationEnabled, flightEnabled, bossBarEnabled, visitorsEnabled,
-            lastBaseSet, lastBaseTeleport, visitorCooldownUntil
+            lastBaseSet, lastBaseTeleport, visitorCooldownUntil, borderEnabled,
+            totalBlocksPlaced, spawnableOverlayEnabled
         );
     }
 
@@ -206,7 +290,8 @@ public record PlayerState(
             warmupLevel, cooldownLevel, grassDirt, stone, deepslate,
             obsidian, placements, baseBreaks,
             navigationEnabled, flightEnabled, bossBarEnabled, visitorsEnabled,
-            lastBaseSet, lastBaseTeleport, visitorCooldownUntil
+            lastBaseSet, lastBaseTeleport, visitorCooldownUntil, borderEnabled,
+            totalBlocksPlaced, spawnableOverlayEnabled
         );
     }
 
@@ -225,7 +310,10 @@ public record PlayerState(
             newWarmupLevel, newCooldownLevel, grassAndDirtBroken, stoneBroken, deepslateBroken,
             obsidianBroken, blocksPlacedInBase, blocksBrokenInBase,
             newNavigationEnabled, newFlightEnabled, bossBarEnabled, newVisitorsEnabled,
-            lastBaseSet, lastBaseTeleport, visitorCooldownUntil
+            lastBaseSet, lastBaseTeleport, visitorCooldownUntil,
+            borderEnabled && newBaseLevel >= 1 && base.isPresent(),
+            totalBlocksPlaced,
+            spawnableOverlayEnabled && newBaseLevel >= 1 && base.isPresent()
         );
     }
 
@@ -235,7 +323,41 @@ public record PlayerState(
             warmupLevel, cooldownLevel, grassAndDirtBroken, stoneBroken, deepslateBroken,
             obsidianBroken, blocksPlacedInBase, blocksBrokenInBase,
             navigationEnabled, flightEnabled, bossBarEnabled, enabled,
-            lastBaseSet, lastBaseTeleport, visitorCooldownUntil
+            lastBaseSet, lastBaseTeleport, visitorCooldownUntil, borderEnabled,
+            totalBlocksPlaced, spawnableOverlayEnabled
+        );
+    }
+
+    public PlayerState withBorderEnabled(boolean enabled) {
+        return new PlayerState(
+            playerId, latestName, base, baseLevel, sizeLevel, flightLevel,
+            warmupLevel, cooldownLevel, grassAndDirtBroken, stoneBroken, deepslateBroken,
+            obsidianBroken, blocksPlacedInBase, blocksBrokenInBase,
+            navigationEnabled, flightEnabled, bossBarEnabled, visitorsEnabled,
+            lastBaseSet, lastBaseTeleport, visitorCooldownUntil, enabled,
+            totalBlocksPlaced, spawnableOverlayEnabled
+        );
+    }
+
+    public PlayerState withTotalBlocksPlaced(long count) {
+        return new PlayerState(
+            playerId, latestName, base, baseLevel, sizeLevel, flightLevel,
+            warmupLevel, cooldownLevel, grassAndDirtBroken, stoneBroken, deepslateBroken,
+            obsidianBroken, blocksPlacedInBase, blocksBrokenInBase,
+            navigationEnabled, flightEnabled, bossBarEnabled, visitorsEnabled,
+            lastBaseSet, lastBaseTeleport, visitorCooldownUntil, borderEnabled,
+            count, spawnableOverlayEnabled
+        );
+    }
+
+    public PlayerState withSpawnableOverlayEnabled(boolean enabled) {
+        return new PlayerState(
+            playerId, latestName, base, baseLevel, sizeLevel, flightLevel,
+            warmupLevel, cooldownLevel, grassAndDirtBroken, stoneBroken, deepslateBroken,
+            obsidianBroken, blocksPlacedInBase, blocksBrokenInBase,
+            navigationEnabled, flightEnabled, bossBarEnabled, visitorsEnabled,
+            lastBaseSet, lastBaseTeleport, visitorCooldownUntil, borderEnabled,
+            totalBlocksPlaced, enabled
         );
     }
 
@@ -247,7 +369,8 @@ public record PlayerState(
             warmupLevel, cooldownLevel, grassAndDirtBroken, stoneBroken, deepslateBroken,
             obsidianBroken, blocksPlacedInBase, blocksBrokenInBase,
             navigationEnabled, flightEnabled, bossBarEnabled, visitorsEnabled,
-            lastBaseSet, lastBaseTeleport, cooldowns
+            lastBaseSet, lastBaseTeleport, cooldowns, borderEnabled,
+            totalBlocksPlaced, spawnableOverlayEnabled
         );
     }
 
@@ -257,7 +380,8 @@ public record PlayerState(
             warmupLevel, cooldownLevel, grassAndDirtBroken, stoneBroken, deepslateBroken,
             obsidianBroken, blocksPlacedInBase, blocksBrokenInBase,
             navigationEnabled, flightEnabled, bossBarEnabled, visitorsEnabled,
-            lastBaseSet, Optional.empty(), visitorCooldownUntil
+            lastBaseSet, Optional.empty(), visitorCooldownUntil, borderEnabled,
+            totalBlocksPlaced, spawnableOverlayEnabled
         );
     }
 
@@ -267,7 +391,8 @@ public record PlayerState(
             warmupLevel, cooldownLevel, grassAndDirtBroken, stoneBroken, deepslateBroken,
             obsidianBroken, blocksPlacedInBase, blocksBrokenInBase,
             navigationEnabled, flightEnabled, bossBarEnabled, visitorsEnabled,
-            lastBaseSet, lastBaseTeleport, Map.of()
+            lastBaseSet, lastBaseTeleport, Map.of(), borderEnabled,
+            totalBlocksPlaced, spawnableOverlayEnabled
         );
     }
 
@@ -277,7 +402,8 @@ public record PlayerState(
             warmupLevel, cooldownLevel, grassAndDirtBroken, stoneBroken, deepslateBroken,
             obsidianBroken, blocksPlacedInBase, blocksBrokenInBase,
             navigationEnabled, flightEnabled, bossBarEnabled, visitorsEnabled,
-            Optional.of(setAt), lastBaseTeleport, visitorCooldownUntil
+            Optional.of(setAt), lastBaseTeleport, visitorCooldownUntil, borderEnabled,
+            totalBlocksPlaced, spawnableOverlayEnabled
         );
     }
 

src/main/java/games/dmg/spigotbase/PluginSettings.java

@@ -21,6 +21,7 @@ public record PluginSettings(
     int flightWarningBuffer,
     int secondFlightVerticalRange,
     int teleportUnlockPlacements,
+    int spawnableOverlayUnlockPlacements,
     int secondWarmupPlacements,
     int thirdWarmupPlacements,
     int instantWarmupPlacements,
@@ -36,11 +37,15 @@ public record PluginSettings(
     long thirdTeleportCooldownSeconds,
     long fourthTeleportCooldownSeconds,
     int visitorUnlockDiamondCost,
+    int pocketBaseUnlockCost,
+    int pocketBaseUpgradeCost,
     Set<String> baseUnlockMaterials,
     String stoneExpansionMaterial,
     String deepslateExpansionMaterial,
     String obsidianExpansionMaterial,
     String visitorCurrencyMaterial,
+    String pocketBaseCurrencyMaterial,
+    String pocketBasePortalFrameMaterial,
     Set<String> cooldownExcludedMaterials,
     int bossBarDurationTicks,
     int navigationParticleCount,
@@ -62,6 +67,7 @@ public record PluginSettings(
     private static final int DEFAULT_FLIGHT_WARNING_BUFFER = 5;
     private static final int DEFAULT_SECOND_FLIGHT_VERTICAL_RANGE = 100;
     private static final int DEFAULT_TELEPORT_UNLOCK_PLACEMENTS = 200;
+    private static final int DEFAULT_SPAWNABLE_OVERLAY_UNLOCK_PLACEMENTS = 250;
     private static final int DEFAULT_SECOND_WARMUP_PLACEMENTS = 1_000;
     private static final int DEFAULT_THIRD_WARMUP_PLACEMENTS = 2_000;
     private static final int DEFAULT_INSTANT_WARMUP_PLACEMENTS = 12_000;
@@ -77,6 +83,8 @@ public record PluginSettings(
     private static final long DEFAULT_THIRD_TELEPORT_COOLDOWN_SECONDS = 3_600L;
     private static final long DEFAULT_FOURTH_TELEPORT_COOLDOWN_SECONDS = 1_800L;
     private static final int DEFAULT_VISITOR_UNLOCK_DIAMOND_COST = 128;
+    private static final int DEFAULT_POCKET_BASE_UNLOCK_COST = 64;
+    private static final int DEFAULT_POCKET_BASE_UPGRADE_COST = 16;
     private static final int DEFAULT_BOSS_BAR_DURATION_TICKS = 60;
     private static final int DEFAULT_NAVIGATION_PARTICLE_COUNT = 5;
     private static final int DEFAULT_TITLE_FADE_IN_TICKS = 10;
@@ -110,6 +118,7 @@ public record PluginSettings(
             throw new IllegalArgumentException("second-flight-vertical-range must exceed the initial range");
         }
         requirePositive(teleportUnlockPlacements, "teleport-unlock-placements");
+        requirePositive(spawnableOverlayUnlockPlacements, "spawnable-overlay-unlock-placements");
         if (secondWarmupPlacements <= teleportUnlockPlacements
                 || thirdWarmupPlacements <= secondWarmupPlacements
                 || instantWarmupPlacements <= thirdWarmupPlacements) {
@@ -137,6 +146,8 @@ public record PluginSettings(
             throw new IllegalArgumentException("teleport cooldown durations must decrease");
         }
         requirePositive(visitorUnlockDiamondCost, "visitor-unlock-diamond-cost");
+        requirePositive(pocketBaseUnlockCost, "pocket-base-unlock-cost");
+        requirePositive(pocketBaseUpgradeCost, "pocket-base-upgrade-cost");
         baseUnlockMaterials = normalizedSet(baseUnlockMaterials, "base-unlock-materials", false);
         stoneExpansionMaterial = normalizedName(stoneExpansionMaterial, "stone-expansion-material");
         deepslateExpansionMaterial = normalizedName(
@@ -148,6 +159,12 @@ public record PluginSettings(
         visitorCurrencyMaterial = normalizedName(
             visitorCurrencyMaterial, "visitor-currency-material"
         );
+        pocketBaseCurrencyMaterial = normalizedName(
+            pocketBaseCurrencyMaterial, "pocket-base-currency-material"
+        );
+        pocketBasePortalFrameMaterial = normalizedName(
+            pocketBasePortalFrameMaterial, "pocket-base-portal-frame-material"
+        );
         cooldownExcludedMaterials = normalizedSet(
             cooldownExcludedMaterials, "cooldown-excluded-materials", true
         );
@@ -175,6 +192,11 @@ public record PluginSettings(
             integer(values, "flight-warning-buffer", DEFAULT_FLIGHT_WARNING_BUFFER),
             integer(values, "second-flight-vertical-range", DEFAULT_SECOND_FLIGHT_VERTICAL_RANGE),
             integer(values, "teleport-unlock-placements", DEFAULT_TELEPORT_UNLOCK_PLACEMENTS),
+            integer(
+                values,
+                "spawnable-overlay-unlock-placements",
+                DEFAULT_SPAWNABLE_OVERLAY_UNLOCK_PLACEMENTS
+            ),
             integer(values, "second-warmup-placements", DEFAULT_SECOND_WARMUP_PLACEMENTS),
             integer(values, "third-warmup-placements", DEFAULT_THIRD_WARMUP_PLACEMENTS),
             integer(values, "instant-warmup-placements", DEFAULT_INSTANT_WARMUP_PLACEMENTS),
@@ -206,11 +228,15 @@ public record PluginSettings(
                 DEFAULT_FOURTH_TELEPORT_COOLDOWN_SECONDS
             ),
             integer(values, "visitor-unlock-diamond-cost", DEFAULT_VISITOR_UNLOCK_DIAMOND_COST),
+            integer(values, "pocket-base-unlock-cost", DEFAULT_POCKET_BASE_UNLOCK_COST),
+            integer(values, "pocket-base-upgrade-cost", DEFAULT_POCKET_BASE_UPGRADE_COST),
             stringSet(values, "base-unlock-materials", Set.of("GRASS_BLOCK", "DIRT")),
             string(values, "stone-expansion-material", "STONE"),
             string(values, "deepslate-expansion-material", "DEEPSLATE"),
             string(values, "obsidian-expansion-material", "OBSIDIAN"),
             string(values, "visitor-currency-material", "DIAMOND"),
+            string(values, "pocket-base-currency-material", "DIAMOND_BLOCK"),
+            string(values, "pocket-base-portal-frame-material", "DIAMOND_BLOCK"),
             stringSet(values, "cooldown-excluded-materials", Set.of()),
             integer(values, "boss-bar-duration-ticks", DEFAULT_BOSS_BAR_DURATION_TICKS),
             integer(values, "navigation-particle-count", DEFAULT_NAVIGATION_PARTICLE_COUNT),

src/main/java/games/dmg/spigotbase/PluginSettingsValidator.java

@@ -13,7 +13,8 @@ final class PluginSettingsValidator {
             Stream.of(
                 settings.stoneExpansionMaterial(),
                 settings.deepslateExpansionMaterial(),
-                settings.obsidianExpansionMaterial()
+                settings.obsidianExpansionMaterial(),
+                settings.pocketBasePortalFrameMaterial()
             )
         ).forEach(name -> {
             Material material = Material.matchMaterial(name);
@@ -26,10 +27,15 @@ final class PluginSettingsValidator {
                 throw new IllegalArgumentException(name + " is not a known material");
             }
         }
-        Material currency = Material.matchMaterial(settings.visitorCurrencyMaterial());
-        if (currency == null || currency.isAir()) {
-            throw new IllegalArgumentException("visitor-currency-material is invalid");
-        }
+        validateCurrency(settings.visitorCurrencyMaterial(), "visitor-currency-material");
+        validateCurrency(settings.pocketBaseCurrencyMaterial(), "pocket-base-currency-material");
         return settings;
     }
+
+    private static void validateCurrency(String name, String setting) {
+        Material currency = Material.matchMaterial(name);
+        if (currency == null || currency.isAir()) {
+            throw new IllegalArgumentException(setting + " is invalid");
+        }
+    }
 }

src/main/java/games/dmg/spigotbase/PocketBaseController.java

@@ -0,0 +1,339 @@
+package games.dmg.spigotbase;
+
+import java.io.IOException;
+import java.util.HashMap;
+import java.util.Map;
+import java.util.Optional;
+import java.util.UUID;
+import java.util.logging.Level;
+import java.util.logging.Logger;
+import org.bukkit.ChatColor;
+import org.bukkit.Location;
+import org.bukkit.Material;
+import org.bukkit.Particle;
+import org.bukkit.Server;
+import org.bukkit.World;
+import org.bukkit.block.Block;
+import org.bukkit.entity.Entity;
+import org.bukkit.entity.Player;
+import org.bukkit.event.EventHandler;
+import org.bukkit.event.EventPriority;
+import org.bukkit.event.Listener;
+import org.bukkit.event.block.Action;
+import org.bukkit.event.block.BlockBreakEvent;
+import org.bukkit.event.block.BlockPlaceEvent;
+import org.bukkit.event.entity.EntityDamageEvent;
+import org.bukkit.event.player.PlayerInteractEvent;
+import org.bukkit.event.player.PlayerMoveEvent;
+import org.bukkit.event.player.PlayerTeleportEvent;
+
+final class PocketBaseController implements Listener, Runnable {
+    private static final int VOID_RETURN_Y = -64;
+    private static final long PORTAL_COOLDOWN_NANOS = 2_000_000_000L;
+    private final Server server;
+    private final BaseStateManager baseStates;
+    private final BaseBoundsService baseBounds;
+    private final PocketBaseManager pocketBases;
+    private final PluginSettingsProvider settings;
+    private final Logger logger;
+    private final Map<UUID, Long> cooldownUntil = new HashMap<>();
+
+    PocketBaseController(
+        Server server,
+        BaseStateManager baseStates,
+        BaseBoundsService baseBounds,
+        PocketBaseManager pocketBases,
+        PluginSettingsProvider settings,
+        Logger logger
+    ) {
+        this.server = server;
+        this.baseStates = baseStates;
+        this.baseBounds = baseBounds;
+        this.pocketBases = pocketBases;
+        this.settings = settings;
+        this.logger = logger;
+    }
+
+    @Override
+    public void run() {
+        validateEntrances();
+        for (PocketBaseState state : pocketBases.knownStates().values()) {
+            state.entrance().ifPresent(this::showPortal);
+            if (state.level() > 0 && pocketBases.returnPortalIsIntact(state.ownerId())) {
+                showPortal(pocketBases.returnPortal(state.ownerId()));
+            }
+        }
+        long now = System.nanoTime();
+        cooldownUntil.entrySet().removeIf(entry -> entry.getValue() <= now);
+    }
+
+    @EventHandler(priority = EventPriority.HIGH, ignoreCancelled = true)
+    public void onActivate(PlayerInteractEvent event) {
+        if (event.getAction() != Action.RIGHT_CLICK_BLOCK || event.getClickedBlock() == null
+                || event.getItem() == null
+                || event.getItem().getType() != Material.FLINT_AND_STEEL) {
+            return;
+        }
+        Player player = event.getPlayer();
+        PocketBaseState pocket = pocketBases.state(player.getUniqueId());
+        if (pocket.level() < 1) {
+            return;
+        }
+        Block clicked = event.getClickedBlock();
+        World world = clicked.getWorld();
+        Material frameMaterial = Material.valueOf(
+            settings.current().pocketBasePortalFrameMaterial()
+        );
+        Optional<PocketPortalLocation> portal = PocketPortalGeometry.findFrame(
+            position(clicked),
+            world.getUID(),
+            world.getName(),
+            candidate -> block(world, candidate).getType() == frameMaterial,
+            candidate -> isAir(block(world, candidate).getType())
+        );
+        if (portal.isEmpty()) {
+            return;
+        }
+        Optional<UUID> pocketOwner = pocketBases.ownerForPocketWorld(world.getUID());
+        if (pocketOwner.isPresent()) {
+            if (!pocketOwner.orElseThrow().equals(player.getUniqueId())) {
+                return;
+            }
+            if (PocketPortalGeometry.frameBlocks(portal.orElseThrow()).stream()
+                    .anyMatch(candidate -> !pocketBases.policy().contains(
+                        pocket.level(), candidate.x(), candidate.z()
+                    ))) {
+                player.sendMessage(ChatColor.RED
+                    + "The complete return portal must be inside your Pocket Base boundary.");
+                event.setCancelled(true);
+                return;
+            }
+            try {
+                pocketBases.activateReturnPortal(player.getUniqueId(), portal.orElseThrow());
+            } catch (IOException | RuntimeException exception) {
+                logger.log(Level.SEVERE, "Could not activate Pocket Base return portal", exception);
+                player.sendMessage(ChatColor.RED
+                    + "The Pocket Base return portal could not be activated.");
+                event.setCancelled(true);
+                return;
+            }
+            event.setCancelled(true);
+            player.sendMessage(ChatColor.GREEN + "Pocket Base return portal activated.");
+            return;
+        }
+        PlayerState owner = baseStates.player(player.getUniqueId(), player.getName());
+        if (owner.baseLevel() < 4 || owner.base().isEmpty()) {
+            return;
+        }
+        BaseArea area = baseBounds.area(owner);
+        if (PocketPortalGeometry.frameBlocks(portal.orElseThrow()).stream().anyMatch(candidate ->
+                !area.contains(world.getUID(), candidate.x(), candidate.y(), candidate.z()))) {
+            player.sendMessage(ChatColor.RED
+                + "The complete Pocket Base portal must be inside your base.");
+            event.setCancelled(true);
+            return;
+        }
+        try {
+            pocketBases.activateEntrance(player.getUniqueId(), portal.orElseThrow());
+        } catch (IOException | RuntimeException exception) {
+            logger.log(Level.SEVERE, "Could not activate Pocket Base entrance", exception);
+            player.sendMessage(ChatColor.RED + "The Pocket Base portal could not be activated.");
+            event.setCancelled(true);
+            return;
+        }
+        event.setCancelled(true);
+        player.sendMessage(ChatColor.GREEN + "Pocket Base portal activated.");
+    }
+
+    @EventHandler(priority = EventPriority.MONITOR, ignoreCancelled = true)
+    public void onBreak(BlockBreakEvent event) {
+        BlockPosition broken = position(event.getBlock());
+        UUID worldId = event.getBlock().getWorld().getUID();
+        for (PocketBaseState state : pocketBases.knownStates().values()) {
+            if (state.entrance().isPresent()) {
+                PocketPortalLocation portal = state.entrance().orElseThrow();
+                if (portal.worldId().equals(worldId)
+                        && PocketPortalGeometry.isFrame(portal, broken)) {
+                    deactivate(state.ownerId());
+                }
+            }
+        }
+    }
+
+    @EventHandler(priority = EventPriority.HIGH, ignoreCancelled = true)
+    public void onPlace(BlockPlaceEvent event) {
+        Block block = event.getBlockPlaced();
+        Optional<UUID> ownerId = pocketBases.ownerForPocketWorld(block.getWorld().getUID());
+        if (ownerId.isEmpty()) {
+            return;
+        }
+        PocketBaseState state = pocketBases.state(ownerId.orElseThrow());
+        if (!pocketBases.policy().contains(state.level(), block.getX(), block.getZ())) {
+            event.setCancelled(true);
+            event.getPlayer().sendMessage(ChatColor.RED
+                + "That block is outside the unlocked Pocket Base boundary.");
+        }
+    }
+
+    @EventHandler(priority = EventPriority.MONITOR, ignoreCancelled = true)
+    public void onMove(PlayerMoveEvent event) {
+        Location destination = event.getTo();
+        if (destination == null || onCooldown(event.getPlayer())) {
+            return;
+        }
+        Player player = event.getPlayer();
+        World world = destination.getWorld();
+        if (world == null) {
+            return;
+        }
+        Optional<UUID> pocketOwner = pocketBases.ownerForPocketWorld(world.getUID());
+        if (pocketOwner.isPresent()) {
+            UUID ownerId = pocketOwner.orElseThrow();
+            if (destination.getY() < VOID_RETURN_Y
+                    || pocketBases.returnPortalIsIntact(ownerId)
+                    && PocketPortalGeometry.isInterior(
+                        pocketBases.returnPortal(ownerId), position(destination)
+                    )) {
+                leavePocket(player, ownerId);
+            }
+            return;
+        }
+        BlockPosition position = position(destination);
+        for (PocketBaseState state : pocketBases.knownStates().values()) {
+            if (state.entrance().isEmpty()) {
+                continue;
+            }
+            PocketPortalLocation portal = state.entrance().orElseThrow();
+            if (portal.worldId().equals(world.getUID())
+                    && isIntact(portal)
+                    && PocketPortalGeometry.isInterior(portal, position)) {
+                teleport(player, pocketBases.pocketArrival(state.ownerId()));
+                return;
+            }
+        }
+    }
+
+    @EventHandler(priority = EventPriority.HIGH, ignoreCancelled = true)
+    public void onVoidDamage(EntityDamageEvent event) {
+        Entity entity = event.getEntity();
+        if (event.getCause() != EntityDamageEvent.DamageCause.VOID
+                || !(entity instanceof Player player)) {
+            return;
+        }
+        Optional<UUID> owner = pocketBases.ownerForPocketWorld(player.getWorld().getUID());
+        if (owner.isPresent()) {
+            event.setCancelled(true);
+            leavePocket(player, owner.orElseThrow());
+        }
+    }
+
+    boolean isPocketWorld(UUID worldId) {
+        return pocketBases.ownerForPocketWorld(worldId).isPresent();
+    }
+
+    void deactivateForRelocation(UUID ownerId) {
+        deactivate(ownerId);
+    }
+
+    private void leavePocket(Player player, UUID ownerId) {
+        PocketBaseState state = pocketBases.state(ownerId);
+        if (state.entrance().isPresent() && isIntact(state.entrance().orElseThrow())) {
+            teleport(player, outsidePortal(state.entrance().orElseThrow()));
+            return;
+        }
+        World fallbackWorld = server.getWorlds().get(0);
+        teleport(player, fallbackWorld.getSpawnLocation());
+    }
+
+    private void teleport(Player player, Location destination) {
+        cooldownUntil.put(player.getUniqueId(), System.nanoTime() + PORTAL_COOLDOWN_NANOS);
+        player.teleport(destination, PlayerTeleportEvent.TeleportCause.PLUGIN);
+    }
+
+    private boolean onCooldown(Player player) {
+        return cooldownUntil.getOrDefault(player.getUniqueId(), 0L) > System.nanoTime();
+    }
+
+    private void validateEntrances() {
+        for (PocketBaseState state : pocketBases.knownStates().values()) {
+            if (state.entrance().isEmpty()) {
+                continue;
+            }
+            PlayerState owner = baseStates.knownPlayers().get(state.ownerId());
+            PocketPortalLocation portal = state.entrance().orElseThrow();
+            if (owner == null || owner.baseLevel() < 4 || owner.base().isEmpty()
+                    || !isIntact(portal)
+                    || PocketPortalGeometry.frameBlocks(portal).stream().anyMatch(position ->
+                        !baseBounds.area(owner).contains(
+                            portal.worldId(), position.x(), position.y(), position.z()
+                        ))) {
+                deactivate(state.ownerId());
+            }
+        }
+    }
+
+    private boolean isIntact(PocketPortalLocation portal) {
+        World world = server.getWorld(portal.worldId());
+        if (world == null) {
+            return false;
+        }
+        Material frame = Material.valueOf(settings.current().pocketBasePortalFrameMaterial());
+        return PocketPortalGeometry.frameBlocks(portal).stream()
+            .allMatch(position -> block(world, position).getType() == frame);
+    }
+
+    private void showPortal(PocketPortalLocation portal) {
+        World world = server.getWorld(portal.worldId());
+        if (world == null || !isIntact(portal)) {
+            return;
+        }
+        for (BlockPosition position : PocketPortalGeometry.interiorBlocks(portal)) {
+            world.spawnParticle(
+                Particle.PORTAL,
+                position.x() + 0.5,
+                position.y() + 0.5,
+                position.z() + 0.5,
+                4,
+                0.25,
+                0.35,
+                0.25,
+                0.02
+            );
+        }
+    }
+
+    private void deactivate(UUID ownerId) {
+        try {
+            pocketBases.deactivateEntrance(ownerId);
+        } catch (IOException exception) {
+            logger.log(Level.SEVERE, "Could not deactivate Pocket Base entrance", exception);
+        }
+    }
+
+    private Location outsidePortal(PocketPortalLocation portal) {
+        World world = server.getWorld(portal.worldId());
+        if (world == null) {
+            return server.getWorlds().get(0).getSpawnLocation();
+        }
+        return portal.axis() == PocketPortalAxis.X
+            ? new Location(world, portal.x() + 2.0, portal.y() + 1.0, portal.z() + 1.5)
+            : new Location(world, portal.x() + 1.5, portal.y() + 1.0, portal.z() + 2.0);
+    }
+
+    private static boolean isAir(Material material) {
+        return material == Material.AIR || material == Material.CAVE_AIR
+            || material == Material.VOID_AIR;
+    }
+
+    private static Block block(World world, BlockPosition position) {
+        return world.getBlockAt(position.x(), position.y(), position.z());
+    }
+
+    private static BlockPosition position(Block block) {
+        return new BlockPosition(block.getX(), block.getY(), block.getZ());
+    }
+
+    private static BlockPosition position(Location location) {
+        return new BlockPosition(location.getBlockX(), location.getBlockY(), location.getBlockZ());
+    }
+}

src/main/java/games/dmg/spigotbase/PocketBaseManager.java

@@ -0,0 +1,120 @@
+package games.dmg.spigotbase;
+
+import java.io.IOException;
+import java.util.Map;
+import java.util.Optional;
+import java.util.UUID;
+import org.bukkit.Location;
+import org.bukkit.World;
+
+final class PocketBaseManager {
+    private final PocketBaseStateManager states;
+    private final PocketBaseWorldService worlds;
+    private final PocketBasePolicy policy;
+
+    PocketBaseManager(
+        PocketBaseStateManager states,
+        PocketBaseWorldService worlds,
+        PluginSettingsProvider settings
+    ) {
+        this.states = states;
+        this.worlds = worlds;
+        this.policy = new PocketBasePolicy(settings);
+    }
+
+    void loadWorlds() {
+        worlds.loadExisting(states.knownStates());
+    }
+
+    PocketBaseState state(UUID ownerId) {
+        return states.state(ownerId);
+    }
+
+    Map<UUID, PocketBaseState> knownStates() {
+        return states.knownStates();
+    }
+
+    PocketBaseState upgrade(UUID ownerId) throws IOException {
+        PocketBaseState current = states.state(ownerId);
+        int nextLevel = Math.addExact(current.level(), 1);
+        policy.size(nextLevel);
+        worlds.expand(ownerId, current.level(), nextLevel);
+        return states.updateAndSave(ownerId, state -> state.withLevel(nextLevel));
+    }
+
+    PocketBaseState activateEntrance(
+        UUID ownerId,
+        PocketPortalLocation portal
+    ) throws IOException {
+        PocketBaseState current = states.state(ownerId);
+        if (current.level() < 1) {
+            throw new IllegalStateException("Pocket Base I is still locked");
+        }
+        return states.updateAndSave(ownerId, state -> state.withEntrance(portal));
+    }
+
+    void deactivateEntrance(UUID ownerId) throws IOException {
+        PocketBaseState current = states.state(ownerId);
+        if (current.entrance().isPresent()) {
+            states.updateAndSave(ownerId, PocketBaseState::withoutEntrance);
+        }
+    }
+
+    PocketBaseState activateReturnPortal(
+        UUID ownerId,
+        PocketPortalLocation portal
+    ) throws IOException {
+        PocketBaseState current = states.state(ownerId);
+        if (current.level() < 1) {
+            throw new IllegalStateException("Pocket Base I is still locked");
+        }
+        return states.updateAndSave(ownerId, state -> state.withReturnPortal(portal));
+    }
+
+    PocketBaseState setMobSpawning(UUID ownerId, boolean enabled) throws IOException {
+        PocketBaseState current = states.state(ownerId);
+        if (current.level() < 1) {
+            throw new IllegalStateException("Pocket Base I is still locked");
+        }
+        worlds.setMobSpawning(ownerId, enabled);
+        try {
+            return states.updateAndSave(
+                ownerId,
+                state -> state.withMobSpawningEnabled(enabled)
+            );
+        } catch (IOException | RuntimeException exception) {
+            try {
+                worlds.setMobSpawning(ownerId, current.mobSpawningEnabled());
+            } catch (RuntimeException rollbackFailure) {
+                exception.addSuppressed(rollbackFailure);
+            }
+            throw exception;
+        }
+    }
+
+    Optional<UUID> ownerForPocketWorld(UUID worldId) {
+        return worlds.ownerForWorld(worldId);
+    }
+
+    Location pocketArrival(UUID ownerId) {
+        return worlds.arrival(ownerId);
+    }
+
+    PocketPortalLocation returnPortal(UUID ownerId) {
+        return states.state(ownerId).returnPortal().orElseGet(
+            () -> worlds.returnPortal(ownerId)
+        );
+    }
+
+    boolean returnPortalIsIntact(UUID ownerId) {
+        return worlds.returnPortalIsIntact(ownerId, returnPortal(ownerId));
+    }
+
+    World pocketWorld(UUID ownerId) {
+        return worlds.world(ownerId);
+    }
+
+    PocketBasePolicy policy() {
+        return policy;
+    }
+}

src/main/java/games/dmg/spigotbase/PocketBasePolicy.java

@@ -0,0 +1,31 @@
+package games.dmg.spigotbase;
+
+public final class PocketBasePolicy {
+    private final PluginSettingsProvider settings;
+
+    public PocketBasePolicy(PluginSettings settings) {
+        this(new PluginSettingsProvider(settings));
+    }
+
+    public PocketBasePolicy(PluginSettingsProvider settings) {
+        this.settings = settings;
+    }
+
+    public int size(int level) {
+        if (level < 1) {
+            throw new IllegalArgumentException("Pocket Base level must be positive");
+        }
+        return Math.addExact(64, Math.multiplyExact(32, level - 1));
+    }
+
+    public int price(PocketBaseState state) {
+        return state.level() == 0
+            ? settings.current().pocketBaseUnlockCost()
+            : settings.current().pocketBaseUpgradeCost();
+    }
+
+    public boolean contains(int level, int x, int z) {
+        int halfSize = size(level) / 2;
+        return x >= -halfSize && x < halfSize && z >= -halfSize && z < halfSize;
+    }
+}

src/main/java/games/dmg/spigotbase/PocketBaseState.java

@@ -0,0 +1,77 @@
+package games.dmg.spigotbase;
+
+import java.util.Optional;
+import java.util.UUID;
+
+public record PocketBaseState(
+    UUID ownerId,
+    int level,
+    Optional<PocketPortalLocation> entrance,
+    Optional<PocketPortalLocation> returnPortal,
+    boolean mobSpawningEnabled
+) {
+    public PocketBaseState {
+        if (ownerId == null) {
+            throw new IllegalArgumentException("owner ID is required");
+        }
+        if (level < 0) {
+            throw new IllegalArgumentException("Pocket Base level must not be negative");
+        }
+        entrance = entrance == null ? Optional.empty() : entrance;
+        returnPortal = returnPortal == null ? Optional.empty() : returnPortal;
+        if (level == 0 && (entrance.isPresent() || returnPortal.isPresent())) {
+            throw new IllegalArgumentException("a locked Pocket Base cannot have a portal");
+        }
+    }
+
+    public PocketBaseState(
+        UUID ownerId,
+        int level,
+        Optional<PocketPortalLocation> entrance
+    ) {
+        this(ownerId, level, entrance, Optional.empty(), false);
+    }
+
+    public PocketBaseState(
+        UUID ownerId,
+        int level,
+        Optional<PocketPortalLocation> entrance,
+        boolean mobSpawningEnabled
+    ) {
+        this(ownerId, level, entrance, Optional.empty(), mobSpawningEnabled);
+    }
+
+    public static PocketBaseState locked(UUID ownerId) {
+        return new PocketBaseState(
+            ownerId, 0, Optional.empty(), Optional.empty(), false
+        );
+    }
+
+    public PocketBaseState withLevel(int newLevel) {
+        return new PocketBaseState(
+            ownerId, newLevel, entrance, returnPortal, mobSpawningEnabled
+        );
+    }
+
+    public PocketBaseState withEntrance(PocketPortalLocation portal) {
+        return new PocketBaseState(
+            ownerId, level, Optional.of(portal), returnPortal, mobSpawningEnabled
+        );
+    }
+
+    public PocketBaseState withoutEntrance() {
+        return new PocketBaseState(
+            ownerId, level, Optional.empty(), returnPortal, mobSpawningEnabled
+        );
+    }
+
+    public PocketBaseState withReturnPortal(PocketPortalLocation portal) {
+        return new PocketBaseState(
+            ownerId, level, entrance, Optional.of(portal), mobSpawningEnabled
+        );
+    }
+
+    public PocketBaseState withMobSpawningEnabled(boolean enabled) {
+        return new PocketBaseState(ownerId, level, entrance, returnPortal, enabled);
+    }
+}

src/main/java/games/dmg/spigotbase/PocketBaseStateManager.java

@@ -0,0 +1,41 @@
+package games.dmg.spigotbase;
+
+import java.io.IOException;
+import java.util.HashMap;
+import java.util.Map;
+import java.util.UUID;
+import java.util.function.UnaryOperator;
+
+final class PocketBaseStateManager {
+    private final YamlPocketBaseRepository repository;
+    private final Map<UUID, PocketBaseState> states;
+
+    PocketBaseStateManager(YamlPocketBaseRepository repository) throws IOException {
+        this.repository = repository;
+        this.states = new HashMap<>(repository.load());
+    }
+
+    PocketBaseState state(UUID ownerId) {
+        return states.getOrDefault(ownerId, PocketBaseState.locked(ownerId));
+    }
+
+    Map<UUID, PocketBaseState> knownStates() {
+        return Map.copyOf(states);
+    }
+
+    PocketBaseState updateAndSave(
+        UUID ownerId,
+        UnaryOperator<PocketBaseState> operation
+    ) throws IOException {
+        PocketBaseState updated = operation.apply(state(ownerId));
+        if (!updated.ownerId().equals(ownerId)) {
+            throw new IllegalArgumentException("Pocket Base owner ID cannot change");
+        }
+        Map<UUID, PocketBaseState> proposed = new HashMap<>(states);
+        proposed.put(ownerId, updated);
+        repository.save(proposed);
+        states.clear();
+        states.putAll(proposed);
+        return updated;
+    }
+}

src/main/java/games/dmg/spigotbase/PocketBaseWorldService.java

@@ -0,0 +1,130 @@
+package games.dmg.spigotbase;
+
+import java.util.HashMap;
+import java.util.Map;
+import java.util.Optional;
+import java.util.UUID;
+import org.bukkit.Location;
+import org.bukkit.Material;
+import org.bukkit.Server;
+import org.bukkit.World;
+import org.bukkit.WorldCreator;
+
+final class PocketBaseWorldService {
+    private static final int PLATFORM_Y = 64;
+    private static final String WORLD_PREFIX = "spigot_base_pocket_";
+    private final Server server;
+    private final PluginSettingsProvider settings;
+    private final PocketBasePolicy policy;
+    private final Map<UUID, UUID> ownersByWorld = new HashMap<>();
+
+    PocketBaseWorldService(Server server, PluginSettingsProvider settings) {
+        this.server = server;
+        this.settings = settings;
+        this.policy = new PocketBasePolicy(settings);
+    }
+
+    void loadExisting(Map<UUID, PocketBaseState> states) {
+        for (PocketBaseState state : states.values()) {
+            if (state.level() > 0) {
+                setMobSpawning(state.ownerId(), state.mobSpawningEnabled());
+            }
+        }
+    }
+
+    World expand(UUID ownerId, int previousLevel, int newLevel) {
+        World world = ensureWorld(ownerId);
+        int newHalfSize = policy.size(newLevel) / 2;
+        int previousHalfSize = previousLevel == 0 ? 0 : policy.size(previousLevel) / 2;
+        for (int x = -newHalfSize; x < newHalfSize; x++) {
+            for (int z = -newHalfSize; z < newHalfSize; z++) {
+                boolean previouslyUnlocked = previousLevel > 0
+                    && x >= -previousHalfSize && x < previousHalfSize
+                    && z >= -previousHalfSize && z < previousHalfSize;
+                if (previouslyUnlocked) {
+                    continue;
+                }
+                for (int y = PLATFORM_Y - 3; y < PLATFORM_Y; y++) {
+                    world.getBlockAt(x, y, z).setType(Material.DIRT, false);
+                }
+                world.getBlockAt(x, PLATFORM_Y, z).setType(Material.GRASS_BLOCK, false);
+            }
+        }
+        if (previousLevel == 0) {
+            createReturnPortal(world);
+            world.setSpawnLocation(0, PLATFORM_Y + 1, 5);
+        }
+        world.save();
+        return world;
+    }
+
+    Optional<UUID> ownerForWorld(UUID worldId) {
+        return Optional.ofNullable(ownersByWorld.get(worldId));
+    }
+
+    World world(UUID ownerId) {
+        return ensureWorld(ownerId);
+    }
+
+    void setMobSpawning(UUID ownerId, boolean enabled) {
+        ensureWorld(ownerId).setSpawnFlags(enabled, enabled);
+    }
+
+    Location arrival(UUID ownerId) {
+        return new Location(ensureWorld(ownerId), 0.5, PLATFORM_Y + 1, 5.5, 180.0f, 0.0f);
+    }
+
+    PocketPortalLocation returnPortal(UUID ownerId) {
+        World world = ensureWorld(ownerId);
+        return new PocketPortalLocation(
+            world.getUID(), world.getName(), -2, PLATFORM_Y + 1, 0, PocketPortalAxis.X
+        );
+    }
+
+    boolean returnPortalIsIntact(UUID ownerId, PocketPortalLocation portal) {
+        World world = ensureWorld(ownerId);
+        if (!portal.worldId().equals(world.getUID())) {
+            return false;
+        }
+        Material frame = Material.valueOf(settings.current().pocketBasePortalFrameMaterial());
+        return PocketPortalGeometry.frameBlocks(portal).stream()
+            .allMatch(position -> world.getBlockAt(
+                position.x(), position.y(), position.z()
+            ).getType() == frame);
+    }
+
+    private World ensureWorld(UUID ownerId) {
+        String name = worldName(ownerId);
+        World world = server.getWorld(name);
+        boolean created = world == null;
+        if (created) {
+            WorldCreator creator = new WorldCreator(name)
+                .environment(World.Environment.NORMAL)
+                .generator(new VoidPocketChunkGenerator())
+                .generateStructures(false);
+            world = server.createWorld(creator);
+        }
+        if (world == null) {
+            throw new IllegalStateException("Could not create Pocket Base world " + name);
+        }
+        if (created) {
+            world.setSpawnFlags(false, false);
+        }
+        ownersByWorld.put(world.getUID(), ownerId);
+        return world;
+    }
+
+    private void createReturnPortal(World world) {
+        PocketPortalLocation portal = new PocketPortalLocation(
+            world.getUID(), world.getName(), -2, PLATFORM_Y + 1, 0, PocketPortalAxis.X
+        );
+        Material frame = Material.valueOf(settings.current().pocketBasePortalFrameMaterial());
+        for (BlockPosition position : PocketPortalGeometry.frameBlocks(portal)) {
+            world.getBlockAt(position.x(), position.y(), position.z()).setType(frame, false);
+        }
+    }
+
+    private static String worldName(UUID ownerId) {
+        return WORLD_PREFIX + ownerId.toString().replace("-", "");
+    }
+}

src/main/java/games/dmg/spigotbase/PocketPortalAxis.java

@@ -0,0 +1,6 @@
+package games.dmg.spigotbase;
+
+public enum PocketPortalAxis {
+    X,
+    Z
+}

src/main/java/games/dmg/spigotbase/PocketPortalGeometry.java

@@ -0,0 +1,83 @@
+package games.dmg.spigotbase;
+
+import java.util.ArrayList;
+import java.util.List;
+import java.util.Optional;
+import java.util.UUID;
+import java.util.function.Predicate;
+
+public final class PocketPortalGeometry {
+    private PocketPortalGeometry() {
+    }
+
+    public static Optional<PocketPortalLocation> findFrame(
+        BlockPosition clicked,
+        UUID worldId,
+        String worldName,
+        Predicate<BlockPosition> isFrameMaterial,
+        Predicate<BlockPosition> isOpenInterior
+    ) {
+        for (PocketPortalAxis axis : PocketPortalAxis.values()) {
+            int clickedHorizontal = axis == PocketPortalAxis.X ? clicked.x() : clicked.z();
+            for (int horizontalOffset = 0; horizontalOffset < 4; horizontalOffset++) {
+                for (int verticalOffset = 0; verticalOffset < 5; verticalOffset++) {
+                    int originHorizontal = clickedHorizontal - horizontalOffset;
+                    int originY = clicked.y() - verticalOffset;
+                    PocketPortalLocation candidate = axis == PocketPortalAxis.X
+                        ? new PocketPortalLocation(
+                            worldId, worldName, originHorizontal, originY, clicked.z(), axis
+                        )
+                        : new PocketPortalLocation(
+                            worldId, worldName, clicked.x(), originY, originHorizontal, axis
+                        );
+                    if (frameBlocks(candidate).stream().allMatch(isFrameMaterial)
+                            && interiorBlocks(candidate).stream().allMatch(isOpenInterior)) {
+                        return Optional.of(candidate);
+                    }
+                }
+            }
+        }
+        return Optional.empty();
+    }
+
+    public static List<BlockPosition> frameBlocks(PocketPortalLocation portal) {
+        List<BlockPosition> blocks = new ArrayList<>(14);
+        for (int horizontal = 0; horizontal < 4; horizontal++) {
+            blocks.add(position(portal, horizontal, 0));
+            blocks.add(position(portal, horizontal, 4));
+        }
+        for (int vertical = 1; vertical < 4; vertical++) {
+            blocks.add(position(portal, 0, vertical));
+            blocks.add(position(portal, 3, vertical));
+        }
+        return List.copyOf(blocks);
+    }
+
+    public static List<BlockPosition> interiorBlocks(PocketPortalLocation portal) {
+        List<BlockPosition> blocks = new ArrayList<>(6);
+        for (int horizontal = 1; horizontal < 3; horizontal++) {
+            for (int vertical = 1; vertical < 4; vertical++) {
+                blocks.add(position(portal, horizontal, vertical));
+            }
+        }
+        return List.copyOf(blocks);
+    }
+
+    public static boolean isFrame(PocketPortalLocation portal, BlockPosition position) {
+        return frameBlocks(portal).contains(position);
+    }
+
+    public static boolean isInterior(PocketPortalLocation portal, BlockPosition position) {
+        return interiorBlocks(portal).contains(position);
+    }
+
+    private static BlockPosition position(
+        PocketPortalLocation portal,
+        int horizontal,
+        int vertical
+    ) {
+        return portal.axis() == PocketPortalAxis.X
+            ? new BlockPosition(portal.x() + horizontal, portal.y() + vertical, portal.z())
+            : new BlockPosition(portal.x(), portal.y() + vertical, portal.z() + horizontal);
+    }
+}

src/main/java/games/dmg/spigotbase/PocketPortalLocation.java

@@ -0,0 +1,24 @@
+package games.dmg.spigotbase;
+
+import java.util.UUID;
+
+public record PocketPortalLocation(
+    UUID worldId,
+    String worldName,
+    int x,
+    int y,
+    int z,
+    PocketPortalAxis axis
+) {
+    public PocketPortalLocation {
+        if (worldId == null) {
+            throw new IllegalArgumentException("portal world ID is required");
+        }
+        if (worldName == null || worldName.isBlank()) {
+            throw new IllegalArgumentException("portal world name is required");
+        }
+        if (axis == null) {
+            throw new IllegalArgumentException("portal axis is required");
+        }
+    }
+}

src/main/java/games/dmg/spigotbase/ProgressCounter.java

@@ -6,5 +6,6 @@ public enum ProgressCounter {
     DEEPSLATE,
     OBSIDIAN,
     PLACEMENTS,
+    TOTAL_PLACEMENTS,
     BASE_BREAKS
 }

src/main/java/games/dmg/spigotbase/SetBaseCommand.java

@@ -16,11 +16,22 @@ final class SetBaseCommand implements CommandExecutor {
     private final BaseStateManager stateManager;
     private final BaseService baseService;
     private final Clock clock;
+    private final PocketBaseController pocketBaseController;
 
     SetBaseCommand(BaseStateManager stateManager, BaseService baseService, Clock clock) {
+        this(stateManager, baseService, clock, null);
+    }
+
+    SetBaseCommand(
+        BaseStateManager stateManager,
+        BaseService baseService,
+        Clock clock,
+        PocketBaseController pocketBaseController
+    ) {
         this.stateManager = stateManager;
         this.baseService = baseService;
         this.clock = clock;
+        this.pocketBaseController = pocketBaseController;
     }
 
     @Override
@@ -47,6 +58,10 @@ final class SetBaseCommand implements CommandExecutor {
             player.sendMessage(ChatColor.RED + "Your current world is unavailable.");
             return true;
         }
+        if (pocketBaseController != null && pocketBaseController.isPocketWorld(world.getUID())) {
+            player.sendMessage(ChatColor.RED + "You cannot set your normal base inside a Pocket Base.");
+            return true;
+        }
         BaseLocation base = new BaseLocation(
             world.getUID(), world.getName(), location.getBlockX(), location.getBlockY(),
             location.getBlockZ(), location.getYaw(), location.getPitch()
@@ -55,6 +70,9 @@ final class SetBaseCommand implements CommandExecutor {
             player.getUniqueId(), player.getName(), current -> baseService.setBase(current, base, now)
         );
         stateManager.saveIfDirty();
+        if (pocketBaseController != null) {
+            pocketBaseController.deactivateForRelocation(player.getUniqueId());
+        }
         player.sendMessage(ChatColor.GREEN + "Base set at " + base.x() + ", " + base.y() + ", " + base.z() + ".");
         return true;
     }

src/main/java/games/dmg/spigotbase/SpawnableBlockPolicy.java

@@ -0,0 +1,38 @@
+package games.dmg.spigotbase;
+
+import org.bukkit.block.Block;
+import org.bukkit.block.BlockFace;
+import org.bukkit.block.data.Bisected;
+import org.bukkit.block.data.type.Slab;
+import org.bukkit.block.data.type.Stairs;
+
+final class SpawnableBlockPolicy {
+    private SpawnableBlockPolicy() {
+    }
+
+    static boolean isCandidate(Block surface) {
+        if (!hasSpawnableTop(surface)) {
+            return false;
+        }
+        Block above = surface.getRelative(BlockFace.UP);
+        Block secondAbove = above.getRelative(BlockFace.UP);
+        return isEmpty(above)
+            && isEmpty(secondAbove)
+            && above.getLightFromBlocks() == 0
+            && above.getLightFromSky() <= 7;
+    }
+
+    private static boolean hasSpawnableTop(Block block) {
+        if (block.getBlockData() instanceof Slab slab) {
+            return slab.getType() == Slab.Type.TOP || slab.getType() == Slab.Type.DOUBLE;
+        }
+        if (block.getBlockData() instanceof Stairs stairs) {
+            return stairs.getHalf() == Bisected.Half.TOP;
+        }
+        return block.getType().isOccluding();
+    }
+
+    private static boolean isEmpty(Block block) {
+        return block.isPassable() && !block.isLiquid();
+    }
+}

src/main/java/games/dmg/spigotbase/SpawnableOverlayController.java

@@ -0,0 +1,185 @@
+package games.dmg.spigotbase;
+
+import java.util.ArrayDeque;
+import java.util.HashMap;
+import java.util.HashSet;
+import java.util.Map;
+import java.util.Set;
+import java.util.UUID;
+import org.bukkit.Color;
+import org.bukkit.Location;
+import org.bukkit.Particle;
+import org.bukkit.Server;
+import org.bukkit.World;
+import org.bukkit.block.Block;
+import org.bukkit.entity.Player;
+
+final class SpawnableOverlayController implements Runnable {
+    static final int HORIZONTAL_RADIUS = 16;
+    static final int VERTICAL_RADIUS = 8;
+    static final int WORK_BUDGET = 2_048;
+    static final int PARTICLE_BUDGET = 128;
+    private static final int PENDING_BUDGET = PARTICLE_BUDGET * 4;
+    private static final int WIDTH = HORIZONTAL_RADIUS * 2 + 1;
+    private static final int HEIGHT = VERTICAL_RADIUS * 2 + 1;
+    private static final int TOTAL_POSITIONS = WIDTH * WIDTH * HEIGHT;
+    private static final Particle.DustOptions RED_DUST =
+        new Particle.DustOptions(Color.RED, 1.0F);
+
+    private final Server server;
+    private final BaseStateManager stateManager;
+    private final BaseBoundsService boundsService;
+    private final PluginSettingsProvider settings;
+    private final Map<UUID, ScanState> scans = new HashMap<>();
+
+    SpawnableOverlayController(
+        Server server,
+        BaseStateManager stateManager,
+        BaseBoundsService boundsService,
+        PluginSettingsProvider settings
+    ) {
+        this.server = server;
+        this.stateManager = stateManager;
+        this.boundsService = boundsService;
+        this.settings = settings;
+    }
+
+    @Override
+    public void run() {
+        Set<UUID> active = new HashSet<>();
+        for (Player player : server.getOnlinePlayers()) {
+            PlayerState playerState = stateManager.player(
+                player.getUniqueId(), player.getName()
+            );
+            if (!eligible(player, playerState)) {
+                scans.remove(player.getUniqueId());
+                continue;
+            }
+            active.add(player.getUniqueId());
+            updateAndRender(player, playerState);
+        }
+        scans.keySet().removeIf(playerId -> !active.contains(playerId));
+    }
+
+    private boolean eligible(Player player, PlayerState state) {
+        return state.spawnableOverlayEnabled()
+            && state.totalBlocksPlaced() >= settings.current()
+                .spawnableOverlayUnlockPlacements()
+            && state.base().isPresent()
+            && player.getWorld().getUID().equals(state.base().orElseThrow().worldId());
+    }
+
+    private void updateAndRender(Player player, PlayerState state) {
+        Location location = player.getLocation();
+        BaseLocation base = state.base().orElseThrow();
+        int centerX = location.getBlockX();
+        int centerY = location.getBlockY() - 1;
+        int centerZ = location.getBlockZ();
+        ScanOrigin origin = new ScanOrigin(
+            player.getWorld().getUID(), centerX, centerY, centerZ,
+            base.x(), base.y(), base.z(), boundsService.radius(state)
+        );
+        ScanState scan = scans.get(player.getUniqueId());
+        if (scan == null || !scan.origin.near(origin)) {
+            scan = new ScanState(origin);
+            scans.put(player.getUniqueId(), scan);
+        }
+        scan(player.getWorld(), boundsService.area(state), scan);
+        render(player, scan);
+    }
+
+    private static void scan(World world, BaseArea base, ScanState scan) {
+        int work = Math.min(WORK_BUDGET, TOTAL_POSITIONS);
+        int minimumWorldY = world.getMinHeight();
+        int maximumWorldY = world.getMaxHeight();
+        UUID worldId = world.getUID();
+        for (int offset = 0; offset < work; offset++) {
+            int index = (scan.cursor + offset) % TOTAL_POSITIONS;
+            int verticalIndex = index % HEIGHT;
+            int horizontalIndex = index / HEIGHT;
+            int zIndex = horizontalIndex % WIDTH;
+            int xIndex = horizontalIndex / WIDTH;
+            int x = scan.origin.centerX + xIndex - HORIZONTAL_RADIUS;
+            int y = scan.origin.centerY + verticalIndex - VERTICAL_RADIUS;
+            int z = scan.origin.centerZ + zIndex - HORIZONTAL_RADIUS;
+            BlockPosition position = new BlockPosition(x, y, z);
+            scan.spawnable.remove(position);
+            int deltaX = x - scan.origin.centerX;
+            int deltaZ = z - scan.origin.centerZ;
+            if (deltaX * deltaX + deltaZ * deltaZ
+                    > HORIZONTAL_RADIUS * HORIZONTAL_RADIUS
+                    || y < minimumWorldY
+                    || y >= maximumWorldY
+                    || !base.contains(worldId, x, y, z)) {
+                continue;
+            }
+            Block surface = world.getBlockAt(x, y, z);
+            if (SpawnableBlockPolicy.isCandidate(surface)) {
+                scan.spawnable.add(position);
+                if (scan.pending.size() < PENDING_BUDGET) {
+                    scan.pending.addLast(position);
+                }
+            }
+        }
+        scan.cursor = (scan.cursor + work) % TOTAL_POSITIONS;
+    }
+
+    private static void render(Player player, ScanState scan) {
+        for (int attempted = 0; attempted < PARTICLE_BUDGET; attempted++) {
+            BlockPosition position = scan.pending.pollFirst();
+            if (position == null) {
+                return;
+            }
+            if (!scan.spawnable.contains(position)) {
+                continue;
+            }
+            player.spawnParticle(
+                Particle.DUST,
+                new Location(
+                    player.getWorld(),
+                    position.x + 0.5,
+                    position.y + 1.05,
+                    position.z + 0.5
+                ),
+                1,
+                RED_DUST
+            );
+        }
+    }
+
+    private record BlockPosition(int x, int y, int z) {
+    }
+
+    private record ScanOrigin(
+        UUID worldId,
+        int centerX,
+        int centerY,
+        int centerZ,
+        int baseX,
+        int baseY,
+        int baseZ,
+        int baseRadius
+    ) {
+        boolean near(ScanOrigin other) {
+            return worldId.equals(other.worldId)
+                && Math.abs(centerX - other.centerX) <= 4
+                && Math.abs(centerY - other.centerY) <= 4
+                && Math.abs(centerZ - other.centerZ) <= 4
+                && baseX == other.baseX
+                && baseY == other.baseY
+                && baseZ == other.baseZ
+                && baseRadius == other.baseRadius;
+        }
+    }
+
+    private static final class ScanState {
+        private final ScanOrigin origin;
+        private final Set<BlockPosition> spawnable = new HashSet<>();
+        private final ArrayDeque<BlockPosition> pending = new ArrayDeque<>();
+        private int cursor;
+
+        private ScanState(ScanOrigin origin) {
+            this.origin = origin;
+        }
+    }
+}

src/main/java/games/dmg/spigotbase/SpawnableOverlayProgressionService.java

@@ -0,0 +1,19 @@
+package games.dmg.spigotbase;
+
+final class SpawnableOverlayProgressionService {
+    private final PluginSettingsProvider settings;
+
+    SpawnableOverlayProgressionService(PluginSettingsProvider settings) {
+        this.settings = settings;
+    }
+
+    SpawnableOverlayProgressionUpdate recordPlacement(PlayerState player) {
+        long previous = player.totalBlocksPlaced();
+        long updated = previous == Long.MAX_VALUE ? Long.MAX_VALUE : previous + 1;
+        int threshold = settings.current().spawnableOverlayUnlockPlacements();
+        return new SpawnableOverlayProgressionUpdate(
+            player.withTotalBlocksPlaced(updated),
+            previous < threshold && updated >= threshold
+        );
+    }
+}

src/main/java/games/dmg/spigotbase/SpawnableOverlayProgressionUpdate.java

@@ -0,0 +1,9 @@
+package games.dmg.spigotbase;
+
+record SpawnableOverlayProgressionUpdate(PlayerState player, boolean unlocked) {
+    SpawnableOverlayProgressionUpdate {
+        if (player == null) {
+            throw new IllegalArgumentException("player is required");
+        }
+    }
+}

src/main/java/games/dmg/spigotbase/SpigotBasePlugin.java

@@ -14,6 +14,8 @@ public final class SpigotBasePlugin extends JavaPlugin {
     private BaseProgressListener progressListener;
     private BaseFlightController flightController;
     private BaseTeleportManager teleportManager;
+    private PocketBaseManager pocketBaseManager;
+    private PocketBaseController pocketBaseController;
 
     @Override
     public void onEnable() {
@@ -27,7 +29,18 @@ public final class SpigotBasePlugin extends JavaPlugin {
                 new YamlBaseStateRepository(getDataFolder().toPath().resolve("state.yml")),
                 getLogger()
             );
-        } catch (IllegalArgumentException | IOException exception) {
+            PocketBaseStateManager pocketStates = new PocketBaseStateManager(
+                new YamlPocketBaseRepository(
+                    getDataFolder().toPath().resolve("pocket-bases.yml")
+                )
+            );
+            pocketBaseManager = new PocketBaseManager(
+                pocketStates,
+                new PocketBaseWorldService(getServer(), settingsProvider),
+                settingsProvider
+            );
+            pocketBaseManager.loadWorlds();
+        } catch (RuntimeException | IOException exception) {
             getLogger().log(Level.SEVERE, "Could not initialize Spigot Base", exception);
             getServer().getPluginManager().disablePlugin(this);
             return;
@@ -46,6 +59,7 @@ public final class SpigotBasePlugin extends JavaPlugin {
             progressionService,
             secondaryProgressionService,
             teleportProgressionService,
+            new SpawnableOverlayProgressionService(settingsProvider),
             boundsService,
             settingsProvider
         );
@@ -61,15 +75,27 @@ public final class SpigotBasePlugin extends JavaPlugin {
             new SafeBaseDestination(),
             Clock.systemUTC()
         );
+        pocketBaseController = new PocketBaseController(
+            getServer(),
+            stateManager,
+            boundsService,
+            pocketBaseManager,
+            settingsProvider,
+            getLogger()
+        );
         getServer().getPluginManager().registerEvents(progressListener, this);
         getServer().getPluginManager().registerEvents(teleportManager, this);
+        getServer().getPluginManager().registerEvents(pocketBaseController, this);
 
-        command("setbase").setExecutor(new SetBaseCommand(stateManager, baseService, Clock.systemUTC()));
+        command("setbase").setExecutor(new SetBaseCommand(
+            stateManager, baseService, Clock.systemUTC(), pocketBaseController
+        ));
         command("base").setExecutor(new BaseCommand(teleportManager));
         BaseSettingsCommand settingsCommand = new BaseSettingsCommand(
             stateManager,
             settingsProvider,
-            flightController
+            flightController,
+            pocketBaseManager
         );
         command("basesettings").setExecutor(settingsCommand);
         command("basesettings").setTabCompleter(settingsCommand);
@@ -91,7 +117,22 @@ public final class SpigotBasePlugin extends JavaPlugin {
             10L,
             10L
         );
+        getServer().getScheduler().runTaskTimer(
+            this,
+            new BaseBorderController(getServer(), stateManager, boundsService),
+            10L,
+            10L
+        );
+        getServer().getScheduler().runTaskTimer(
+            this,
+            new SpawnableOverlayController(
+                getServer(), stateManager, boundsService, settingsProvider
+            ),
+            10L,
+            10L
+        );
         getServer().getScheduler().runTaskTimer(this, flightController, 5L, 5L);
+        getServer().getScheduler().runTaskTimer(this, pocketBaseController, 5L, 5L);
         getServer().getScheduler().runTaskTimer(this, stateManager::saveIfDirty, 600L, 600L);
         getLogger().info("Spigot Base enabled.");
     }

src/main/java/games/dmg/spigotbase/TeleportPolicy.java

@@ -25,6 +25,13 @@ public final class TeleportPolicy {
         };
     }
 
+    public Duration visitorWarmup(PlayerState owner) {
+        Duration warmup = warmup(owner);
+        return warmup.compareTo(Duration.ofSeconds(1)) < 0
+            ? Duration.ofSeconds(1)
+            : warmup;
+    }
+
     public Duration cooldown(PlayerState player) {
         return switch (player.cooldownLevel()) {
             case 0 -> Duration.ofSeconds(settings.current().initialTeleportCooldownSeconds());

src/main/java/games/dmg/spigotbase/VoidPocketChunkGenerator.java

@@ -0,0 +1,35 @@
+package games.dmg.spigotbase;
+
+import org.bukkit.generator.ChunkGenerator;
+
+final class VoidPocketChunkGenerator extends ChunkGenerator {
+    @Override
+    public boolean shouldGenerateNoise() {
+        return false;
+    }
+
+    @Override
+    public boolean shouldGenerateSurface() {
+        return false;
+    }
+
+    @Override
+    public boolean shouldGenerateCaves() {
+        return false;
+    }
+
+    @Override
+    public boolean shouldGenerateDecorations() {
+        return false;
+    }
+
+    @Override
+    public boolean shouldGenerateMobs() {
+        return false;
+    }
+
+    @Override
+    public boolean shouldGenerateStructures() {
+        return false;
+    }
+}

src/main/java/games/dmg/spigotbase/YamlBaseStateRepository.java

@@ -127,7 +127,10 @@ public final class YamlBaseStateRepository {
                     yaml.getBoolean(path + ".visitors-enabled", false),
                     instant(yaml, path + ".last-base-set-epoch-millis"),
                     instant(yaml, path + ".last-base-teleport-epoch-millis"),
-                    loadVisitorCooldowns(yaml, path + ".visitor-cooldowns")
+                    loadVisitorCooldowns(yaml, path + ".visitor-cooldowns"),
+                    yaml.getBoolean(path + ".border-enabled", false),
+                    totalPlacementCount(yaml, path),
+                    yaml.getBoolean(path + ".spawnable-overlay-enabled", false)
                 );
                 players.put(playerId, player);
             } catch (IllegalArgumentException ignored) {
@@ -194,6 +197,13 @@ public final class YamlBaseStateRepository {
         return yaml.getLong(path);
     }
 
+    private static long totalPlacementCount(YamlConfiguration yaml, String playerPath) {
+        return Math.max(
+            count(yaml, playerPath + ".total-blocks-placed"),
+            count(yaml, playerPath + ".blocks-placed-in-base")
+        );
+    }
+
     private static Optional<Instant> instant(YamlConfiguration yaml, String path) {
         if (!yaml.isLong(path) && !yaml.isInt(path)) {
             return Optional.empty();
@@ -222,6 +232,9 @@ public final class YamlBaseStateRepository {
             yaml.set(path + ".flight-enabled", player.flightEnabled());
             yaml.set(path + ".boss-bar-enabled", player.bossBarEnabled());
             yaml.set(path + ".visitors-enabled", player.visitorsEnabled());
+            yaml.set(path + ".border-enabled", player.borderEnabled());
+            yaml.set(path + ".total-blocks-placed", player.totalBlocksPlaced());
+            yaml.set(path + ".spawnable-overlay-enabled", player.spawnableOverlayEnabled());
             yaml.set(
                 path + ".last-base-set-epoch-millis",
                 player.lastBaseSet().map(Instant::toEpochMilli).orElse(null)

src/main/java/games/dmg/spigotbase/YamlPocketBaseRepository.java

@@ -0,0 +1,127 @@
+package games.dmg.spigotbase;
+
+import java.io.IOException;
+import java.nio.file.Files;
+import java.nio.file.Path;
+import java.nio.file.StandardCopyOption;
+import java.util.HashMap;
+import java.util.Map;
+import java.util.Optional;
+import java.util.UUID;
+import org.bukkit.configuration.ConfigurationSection;
+import org.bukkit.configuration.InvalidConfigurationException;
+import org.bukkit.configuration.file.YamlConfiguration;
+
+public final class YamlPocketBaseRepository {
+    private final Path stateFile;
+
+    public YamlPocketBaseRepository(Path stateFile) {
+        this.stateFile = stateFile;
+    }
+
+    public Map<UUID, PocketBaseState> load() throws IOException {
+        if (!Files.exists(stateFile)) {
+            return Map.of();
+        }
+        YamlConfiguration yaml = new YamlConfiguration();
+        try {
+            yaml.load(stateFile.toFile());
+        } catch (InvalidConfigurationException exception) {
+            throw new IOException("Pocket Base state is not valid YAML", exception);
+        }
+        Map<UUID, PocketBaseState> states = new HashMap<>();
+        ConfigurationSection owners = yaml.getConfigurationSection("owners");
+        if (owners == null) {
+            return states;
+        }
+        for (String key : owners.getKeys(false)) {
+            try {
+                UUID ownerId = UUID.fromString(key);
+                String path = "owners." + key;
+                int level = yaml.getInt(path + ".level", 0);
+                PocketBaseState state = new PocketBaseState(
+                    ownerId,
+                    level,
+                    loadPortal(yaml, path + ".entrance"),
+                    loadPortal(yaml, path + ".return-portal"),
+                    yaml.getBoolean(path + ".mob-spawning-enabled", false)
+                );
+                states.put(ownerId, state);
+            } catch (IllegalArgumentException ignored) {
+                // Invalid records grant no Pocket Base progression.
+            }
+        }
+        return states;
+    }
+
+    public void save(Map<UUID, PocketBaseState> states) throws IOException {
+        Path parent = stateFile.toAbsolutePath().getParent();
+        if (parent != null) {
+            Files.createDirectories(parent);
+        }
+        YamlConfiguration yaml = new YamlConfiguration();
+        for (PocketBaseState state : states.values()) {
+            String path = "owners." + state.ownerId();
+            yaml.set(path + ".level", state.level());
+            yaml.set(path + ".mob-spawning-enabled", state.mobSpawningEnabled());
+            state.entrance().ifPresent(portal -> savePortal(yaml, path + ".entrance", portal));
+            state.returnPortal().ifPresent(portal ->
+                savePortal(yaml, path + ".return-portal", portal)
+            );
+        }
+        Path temporary = Files.createTempFile(parent, "spigot-base-pocket-", ".yml");
+        try {
+            yaml.save(temporary.toFile());
+            try {
+                Files.move(
+                    temporary,
+                    stateFile,
+                    StandardCopyOption.REPLACE_EXISTING,
+                    StandardCopyOption.ATOMIC_MOVE
+                );
+            } catch (IOException atomicMoveFailure) {
+                Files.move(temporary, stateFile, StandardCopyOption.REPLACE_EXISTING);
+            }
+        } finally {
+            Files.deleteIfExists(temporary);
+        }
+    }
+
+    private static Optional<PocketPortalLocation> loadPortal(
+        YamlConfiguration yaml,
+        String path
+    ) {
+        if (!yaml.isConfigurationSection(path)) {
+            return Optional.empty();
+        }
+        String worldId = yaml.getString(path + ".world-id");
+        String worldName = yaml.getString(path + ".world-name");
+        String axis = yaml.getString(path + ".axis");
+        if (worldId == null || worldName == null || axis == null
+                || !yaml.isInt(path + ".x") || !yaml.isInt(path + ".y")
+                || !yaml.isInt(path + ".z")) {
+            throw new IllegalArgumentException("invalid Pocket Base portal");
+        }
+        return Optional.of(new PocketPortalLocation(
+            UUID.fromString(worldId),
+            worldName,
+            yaml.getInt(path + ".x"),
+            yaml.getInt(path + ".y"),
+            yaml.getInt(path + ".z"),
+            PocketPortalAxis.valueOf(axis)
+        ));
+    }
+
+    private static void savePortal(
+        YamlConfiguration yaml,
+        String path,
+        PocketPortalLocation portal
+    ) {
+        yaml.set(path + ".world-id", portal.worldId().toString());
+        yaml.set(path + ".world-name", portal.worldName());
+        yaml.set(path + ".x", portal.x());
+        yaml.set(path + ".y", portal.y());
+        yaml.set(path + ".z", portal.z());
+        yaml.set(path + ".axis", portal.axis().name());
+    }
+}

src/main/resources/config.yml

@@ -46,6 +46,15 @@ fourth-teleport-cooldown-seconds: 1800
 visitor-unlock-diamond-cost: 128
 visitor-currency-material: DIAMOND
 
+# Pocket Base
+pocket-base-unlock-cost: 64
+pocket-base-upgrade-cost: 16
+pocket-base-currency-material: DIAMOND_BLOCK
+pocket-base-portal-frame-material: DIAMOND_BLOCK
+
+# Spawnable block overlay
+spawnable-overlay-unlock-placements: 250
+
 # Progress and notification presentation
 cooldown-excluded-materials: []
 boss-bar-duration-ticks: 60

src/main/resources/plugin.yml

@@ -19,7 +19,7 @@ commands:
     aliases: [visit]
   basesettings:
     description: View progression, upgrade, and manage base settings.
-    usage: /basesettings [status|upgrade|visitors|navigation|flight|bossbar]
+    usage: /basesettings [status|upgrade|pocket|visitors|navigation|flight|border|spawnable|bossbar]
     aliases: [homesettings]
   baseadmin:
     description: Administer Spigot Base.

src/test/java/games/dmg/spigotbase/AdminProgressCounterTest.java

@@ -11,6 +11,19 @@ final class AdminProgressCounterTest {
         new PluginSettingsProvider(PluginSettings.from(Map.of()))
     );
 
+    @Test
+    void settingTotalPlacementCounterUnlocksSpawnableOverlay() {
+        PlayerState player = PlayerState.newPlayer(UUID.randomUUID(), "Alex");
+
+        PlayerState updated = service.setProgress(
+            player,
+            ProgressCounter.TOTAL_PLACEMENTS,
+            250
+        );
+
+        assertEquals(250, updated.totalBlocksPlaced());
+    }
+
     @Test
     void settingPlacementCounterEvaluatesBaseAndWarmupTiers() {
         PlayerState player = PlayerState.newPlayer(UUID.randomUUID(), "Alex");

src/test/java/games/dmg/spigotbase/AdminProgressionServiceTest.java

@@ -4,6 +4,7 @@ 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 java.time.Instant;
 import java.util.UUID;
 import org.junit.jupiter.api.Test;
 
@@ -36,6 +37,40 @@ final class AdminProgressionServiceTest {
         assertFalse(updated.visitorsEnabled());
     }
 
+    @Test
+    void loweringBaseDisablesBorderVisualization() {
+        UUID playerId = UUID.randomUUID();
+        PlayerState player = PlayerState.newPlayer(playerId, "Alex")
+            .withAdministrativeLevels(1, 0, 0, 0, 0, false, false, false)
+            .withBase(
+                new BaseLocation(UUID.randomUUID(), "world", 0, 64, 0, 0, 0),
+                Instant.EPOCH
+            )
+            .withBorderEnabled(true);
+
+        PlayerState updated = service.setLevel(player, ProgressionPath.BASE, 0);
+
+        assertFalse(updated.borderEnabled());
+    }
+
+    @Test
+    void completeResetClearsSpawnableOverlayProgressAndPreference() {
+        UUID playerId = UUID.randomUUID();
+        PlayerState player = PlayerState.newPlayer(playerId, "Alex")
+            .withAdministrativeLevels(1, 0, 0, 0, 0, false, false, false)
+            .withBase(
+                new BaseLocation(UUID.randomUUID(), "world", 0, 64, 0, 0, 0),
+                Instant.EPOCH
+            )
+            .withTotalBlocksPlaced(250)
+            .withSpawnableOverlayEnabled(true);
+
+        PlayerState updated = service.resetPath(player, ProgressionPath.BASE);
+
+        assertEquals(0, updated.totalBlocksPlaced());
+        assertFalse(updated.spawnableOverlayEnabled());
+    }
+
     @Test
     void rejectsUnknownLevel() {
         PlayerState player = PlayerState.newPlayer(UUID.randomUUID(), "Alex");

src/test/java/games/dmg/spigotbase/BaseAdminCommandTest.java

@@ -1,6 +1,7 @@
 package games.dmg.spigotbase;
 
 import static org.junit.jupiter.api.Assertions.assertEquals;
+import static org.junit.jupiter.api.Assertions.assertTrue;
 import static org.mockito.ArgumentMatchers.any;
 import static org.mockito.ArgumentMatchers.anyString;
 import static org.mockito.Mockito.mock;
@@ -9,10 +10,13 @@ import static org.mockito.Mockito.never;
 import static org.mockito.Mockito.verify;
 import static org.mockito.Mockito.when;
 
+import java.time.Instant;
 import java.util.List;
 import java.util.Map;
 import java.util.Optional;
 import java.util.UUID;
+import java.util.concurrent.atomic.AtomicReference;
+import java.util.function.UnaryOperator;
 import org.bukkit.Bukkit;
 import org.bukkit.ChatColor;
 import org.bukkit.command.CommandSender;
@@ -22,6 +26,46 @@ import org.junit.jupiter.api.Test;
 import org.mockito.MockedStatic;
 
 final class BaseAdminCommandTest {
+    @Test
+    void adminCanEnableUnlockedSpawnableOverlayForPlayer() {
+        CommandSender sender = mock(CommandSender.class);
+        when(sender.hasPermission("spigotbase.admin")).thenReturn(true);
+        UUID playerId = UUID.randomUUID();
+        PlayerState target = PlayerState.newPlayer(playerId, "Builder")
+            .withAdministrativeLevels(1, 0, 0, 0, 0, false, false, false)
+            .withBase(
+                new BaseLocation(UUID.randomUUID(), "world", 0, 64, 0, 0, 0),
+                Instant.EPOCH
+            )
+            .withTotalBlocksPlaced(250);
+        AtomicReference<PlayerState> updated = new AtomicReference<>();
+        BaseStateManager stateManager = mock(BaseStateManager.class);
+        when(stateManager.findByName("Builder")).thenReturn(Optional.of(target));
+        when(stateManager.update(any(), anyString(), any())).thenAnswer(invocation -> {
+            @SuppressWarnings("unchecked")
+            UnaryOperator<PlayerState> operation = invocation.getArgument(2);
+            PlayerState result = operation.apply(target);
+            updated.set(result);
+            return result;
+        });
+        BaseAdminCommand command = new BaseAdminCommand(
+            mock(JavaPlugin.class),
+            stateManager,
+            new AdminProgressionService(
+                new PluginSettingsProvider(PluginSettings.from(Map.of()))
+            ),
+            new PluginSettingsProvider(PluginSettings.from(Map.of()))
+        );
+
+        try (MockedStatic<Bukkit> bukkit = mockStatic(Bukkit.class)) {
+            bukkit.when(() -> Bukkit.getPlayerExact("Builder")).thenReturn(null);
+            command.onCommand(sender, null, "baseadmin",
+                new String[] {"setsetting", "Builder", "spawnable", "enable"});
+        }
+
+        assertTrue(updated.get().spawnableOverlayEnabled());
+    }
+
     @Test
     void invalidPathShowsFriendlyUsage() {
         CommandSender sender = mock(CommandSender.class);
@@ -92,10 +136,23 @@ final class BaseAdminCommandTest {
                 new String[] {"setlevel", "Builder", ""})
         );
         assertEquals(
-            List.of("grass_dirt", "stone", "deepslate", "obsidian", "placements", "base_breaks"),
+            List.of(
+                "grass_dirt", "stone", "deepslate", "obsidian", "placements",
+                "total_placements", "base_breaks"
+            ),
             command.onTabComplete(sender, null, "baseadmin",
                 new String[] {"setprogress", "Builder", ""})
         );
+        assertEquals(
+            List.of("spawnable"),
+            command.onTabComplete(sender, null, "baseadmin",
+                new String[] {"setsetting", "Builder", ""})
+        );
+        assertEquals(
+            List.of("enable"),
+            command.onTabComplete(sender, null, "baseadmin",
+                new String[] {"setsetting", "Builder", "spawnable", "e"})
+        );
         assertEquals(
             List.of("personal", "visitor", "all"),
             command.onTabComplete(sender, null, "baseadmin",
@@ -108,6 +165,42 @@ final class BaseAdminCommandTest {
         );
     }
 
+    @Test
+    void adminCanChangeSpawnableOverlayUnlockThreshold() {
+        CommandSender sender = mock(CommandSender.class);
+        when(sender.hasPermission("spigotbase.admin")).thenReturn(true);
+        JavaPlugin plugin = mock(JavaPlugin.class);
+        FileConfiguration configuration = mock(FileConfiguration.class);
+        when(plugin.getConfig()).thenReturn(configuration);
+        when(configuration.get("spawnable-overlay-unlock-placements")).thenReturn(250);
+        when(configuration.getValues(false)).thenReturn(Map.of(
+            "spawnable-overlay-unlock-placements", 250
+        ));
+        PluginSettingsProvider settings = new PluginSettingsProvider(
+            PluginSettings.from(Map.of())
+        );
+        BaseAdminCommand command = new BaseAdminCommand(
+            plugin,
+            mock(BaseStateManager.class),
+            mock(AdminProgressionService.class),
+            settings
+        );
+
+        try (MockedStatic<PluginSettingsValidator> validator =
+                mockStatic(PluginSettingsValidator.class)) {
+            validator.when(() -> PluginSettingsValidator.validateMaterials(
+                any(PluginSettings.class)
+            )).thenAnswer(invocation -> invocation.getArgument(0));
+            command.onCommand(sender, null, "baseadmin", new String[] {
+                "config", "spawnable-overlay-unlock-placements", "500"
+            });
+        }
+
+        verify(configuration).set("spawnable-overlay-unlock-placements", 500L);
+        verify(plugin).saveConfig();
+        assertEquals(500, settings.current().spawnableOverlayUnlockPlacements());
+    }
+
     @Test
     void autocompletesNumericConfigurationKeys() {
         CommandSender sender = mock(CommandSender.class);
@@ -169,7 +262,10 @@ final class BaseAdminCommandTest {
         );
 
         assertEquals(
-            List.of("status", "setlevel", "setprogress", "clearcooldown", "reset", "config"),
+            List.of(
+                "status", "setlevel", "setprogress", "setsetting", "clearcooldown", "reset",
+                "config"
+            ),
             command.onTabComplete(sender, null, "baseadmin", new String[] {""})
         );
     }

src/test/java/games/dmg/spigotbase/BaseBorderControllerTest.java

@@ -0,0 +1,92 @@
+package games.dmg.spigotbase;
+
+import static org.mockito.ArgumentMatchers.any;
+import static org.mockito.ArgumentMatchers.eq;
+import static org.mockito.Mockito.atLeastOnce;
+import static org.mockito.Mockito.doReturn;
+import static org.mockito.Mockito.mock;
+import static org.mockito.Mockito.never;
+import static org.mockito.Mockito.verify;
+import static org.mockito.Mockito.when;
+
+import java.time.Instant;
+import java.util.Map;
+import java.util.UUID;
+import org.bukkit.Location;
+import org.bukkit.Particle;
+import org.bukkit.Server;
+import org.bukkit.World;
+import org.bukkit.entity.Player;
+import org.junit.jupiter.api.Test;
+
+final class BaseBorderControllerTest {
+    @Test
+    void doesNotRenderOutsideTheBaseVerticalRange() {
+        UUID playerId = UUID.randomUUID();
+        UUID worldId = UUID.randomUUID();
+        PlayerState state = PlayerState.newPlayer(playerId, "Builder")
+            .withAdministrativeLevels(1, 0, 0, 0, 0, false, false, false)
+            .withBase(new BaseLocation(worldId, "world", 0, 64, 0, 0, 0), Instant.EPOCH)
+            .withBorderEnabled(true);
+
+        World world = mock(World.class);
+        when(world.getUID()).thenReturn(worldId);
+        Player player = mock(Player.class);
+        when(player.getUniqueId()).thenReturn(playerId);
+        when(player.getName()).thenReturn("Builder");
+        when(player.getWorld()).thenReturn(world);
+        when(player.getLocation()).thenReturn(new Location(world, 10.5, 100.0, 0.5));
+        Server server = mock(Server.class);
+        doReturn(java.util.List.of(player)).when(server).getOnlinePlayers();
+        BaseStateManager stateManager = mock(BaseStateManager.class);
+        when(stateManager.player(playerId, "Builder")).thenReturn(state);
+
+        new BaseBorderController(
+            server,
+            stateManager,
+            new BaseBoundsService(PluginSettings.from(Map.of()))
+        ).run();
+
+        verify(player, never()).spawnParticle(
+            eq(Particle.END_ROD),
+            any(Location.class),
+            eq(1),
+            eq(0.0), eq(0.0), eq(0.0), eq(0.0)
+        );
+    }
+
+    @Test
+    void ownerSeesParticlesAtCurrentHeightNearEnabledBorder() {
+        UUID playerId = UUID.randomUUID();
+        UUID worldId = UUID.randomUUID();
+        PlayerState state = PlayerState.newPlayer(playerId, "Builder")
+            .withAdministrativeLevels(1, 0, 0, 0, 0, false, false, false)
+            .withBase(new BaseLocation(worldId, "world", 0, 64, 0, 0, 0), Instant.EPOCH)
+            .withBorderEnabled(true);
+
+        World world = mock(World.class);
+        when(world.getUID()).thenReturn(worldId);
+        Player player = mock(Player.class);
+        when(player.getUniqueId()).thenReturn(playerId);
+        when(player.getName()).thenReturn("Builder");
+        when(player.getWorld()).thenReturn(world);
+        when(player.getLocation()).thenReturn(new Location(world, 10.5, 70.0, 0.5));
+        Server server = mock(Server.class);
+        doReturn(java.util.List.of(player)).when(server).getOnlinePlayers();
+        BaseStateManager stateManager = mock(BaseStateManager.class);
+        when(stateManager.player(playerId, "Builder")).thenReturn(state);
+
+        new BaseBorderController(
+            server,
+            stateManager,
+            new BaseBoundsService(PluginSettings.from(Map.of()))
+        ).run();
+
+        verify(player, atLeastOnce()).spawnParticle(
+            eq(Particle.END_ROD),
+            any(Location.class),
+            eq(1),
+            eq(0.0), eq(0.0), eq(0.0), eq(0.0)
+        );
+    }
+}

src/test/java/games/dmg/spigotbase/BaseBorderGeometryTest.java

@@ -0,0 +1,27 @@
+package games.dmg.spigotbase;
+
+import static org.junit.jupiter.api.Assertions.assertFalse;
+import static org.junit.jupiter.api.Assertions.assertTrue;
+
+import java.util.List;
+import org.junit.jupiter.api.Test;
+
+final class BaseBorderGeometryTest {
+    @Test
+    void producesBoundedPointsOnTheCurrentCircularBoundary() {
+        List<BaseBorderGeometry.Point> points = BaseBorderGeometry.visiblePoints(
+            0.5, 0.5, 150, 150.5, 0.5
+        );
+
+        assertFalse(points.isEmpty());
+        assertTrue(points.size() <= BaseBorderGeometry.MAX_PARTICLES);
+        assertTrue(points.stream().allMatch(point ->
+            Math.abs(Math.hypot(point.x() - 0.5, point.z() - 0.5) - 150.0) < 0.0001
+        ));
+    }
+
+    @Test
+    void omitsParticlesWhenPlayerIsFarFromBoundary() {
+        assertTrue(BaseBorderGeometry.visiblePoints(0.5, 0.5, 10, 100.5, 0.5).isEmpty());
+    }
+}

src/test/java/games/dmg/spigotbase/BaseFlightControllerTest.java

@@ -0,0 +1,93 @@
+package games.dmg.spigotbase;
+
+import static org.mockito.ArgumentMatchers.anyInt;
+import static org.mockito.ArgumentMatchers.anyString;
+import static org.mockito.Mockito.doReturn;
+import static org.mockito.Mockito.mock;
+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.Instant;
+import java.util.List;
+import java.util.Map;
+import java.util.UUID;
+import org.bukkit.Location;
+import org.bukkit.Server;
+import org.bukkit.World;
+import org.bukkit.entity.Player;
+import org.bukkit.inventory.ItemStack;
+import org.bukkit.inventory.PlayerInventory;
+import org.junit.jupiter.api.BeforeEach;
+import org.junit.jupiter.api.Test;
+
+final class BaseFlightControllerTest {
+    private final UUID playerId = UUID.randomUUID();
+    private final UUID worldId = UUID.randomUUID();
+    private final Server server = mock(Server.class);
+    private final BaseStateManager stateManager = mock(BaseStateManager.class);
+    private final Player player = mock(Player.class);
+    private final PlayerState state = PlayerState.newPlayer(playerId, "Alex")
+        .withGrassAndDirtProgress(250, 1)
+        .withBase(new BaseLocation(worldId, "world", 0, 64, 0, 0, 0), Instant.EPOCH)
+        .withFlightLevel(1, true);
+    private final BaseFlightController controller = new BaseFlightController(
+        server,
+        stateManager,
+        new SecondaryProgressionService(PluginSettings.from(Map.of())),
+        new BaseBoundsService(PluginSettings.from(Map.of())),
+        new PluginSettingsProvider(PluginSettings.from(Map.of()))
+    );
+
+    @BeforeEach
+    void setUp() {
+        World world = mock(World.class);
+        Location location = mock(Location.class);
+        PlayerInventory inventory = mock(PlayerInventory.class);
+
+        doReturn(List.of(player)).when(server).getOnlinePlayers();
+        when(player.getUniqueId()).thenReturn(playerId);
+        when(player.getName()).thenReturn("Alex");
+        when(player.getGameMode()).thenReturn(org.bukkit.GameMode.SURVIVAL);
+        when(player.getInventory()).thenReturn(inventory);
+        when(inventory.getStorageContents()).thenReturn(new ItemStack[0]);
+        when(stateManager.player(playerId, "Alex")).thenReturn(state);
+        when(player.getWorld()).thenReturn(world);
+        when(world.getUID()).thenReturn(worldId);
+        when(player.getLocation()).thenReturn(location);
+        when(location.getX()).thenReturn(12.5);
+        when(location.getZ()).thenReturn(0.5);
+        when(location.getBlockY()).thenReturn(64);
+        when(player.getAllowFlight()).thenReturn(true);
+    }
+
+    @Test
+    void walkingInWarningBufferDoesNotShowLeavingBaseWarning() {
+        when(player.isFlying()).thenReturn(false);
+
+        controller.run();
+
+        verify(player, never()).sendTitle(anyString(), anyString(), anyInt(), anyInt(), anyInt());
+    }
+
+    @Test
+    void flyingInWarningBufferShowsLeavingBaseWarning() {
+        when(player.isFlying()).thenReturn(true);
+
+        controller.run();
+
+        verify(player).sendTitle(anyString(), anyString(), anyInt(), anyInt(), anyInt());
+    }
+
+    @Test
+    void warningCanAppearAgainAfterPlayerStopsAndResumesFlyingInBuffer() {
+        when(player.isFlying()).thenReturn(true, false, true);
+
+        controller.run();
+        controller.run();
+        controller.run();
+
+        verify(player, times(2)).sendTitle(anyString(), anyString(), anyInt(), anyInt(), anyInt());
+    }
+}

src/test/java/games/dmg/spigotbase/BaseNavigationControllerTest.java

@@ -0,0 +1,60 @@
+package games.dmg.spigotbase;
+
+import static org.mockito.ArgumentMatchers.any;
+import static org.mockito.ArgumentMatchers.eq;
+import static org.mockito.Mockito.doReturn;
+import static org.mockito.Mockito.mock;
+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.Instant;
+import java.util.Map;
+import java.util.UUID;
+import org.bukkit.Location;
+import org.bukkit.Particle;
+import org.bukkit.Server;
+import org.bukkit.World;
+import org.bukkit.entity.Player;
+import org.junit.jupiter.api.Test;
+
+final class BaseNavigationControllerTest {
+    @Test
+    void showsParticlesOnlyMoreThanTwentyFiveBlocksBeyondBorder() {
+        UUID playerId = UUID.randomUUID();
+        UUID worldId = UUID.randomUUID();
+        PlayerState state = PlayerState.newPlayer(playerId, "Builder")
+            .withAdministrativeLevels(2, 0, 0, 0, 0, true, false, false)
+            .withBase(new BaseLocation(worldId, "world", 0, 64, 0, 0, 0), Instant.EPOCH);
+        World world = mock(World.class);
+        when(world.getUID()).thenReturn(worldId);
+        Player player = mock(Player.class);
+        when(player.getUniqueId()).thenReturn(playerId);
+        when(player.getName()).thenReturn("Builder");
+        when(player.getWorld()).thenReturn(world);
+        when(player.getLocation()).thenReturn(new Location(world, 35.5, 64.0, 0.5));
+        Server server = mock(Server.class);
+        doReturn(java.util.List.of(player)).when(server).getOnlinePlayers();
+        BaseStateManager stateManager = mock(BaseStateManager.class);
+        when(stateManager.player(playerId, "Builder")).thenReturn(state);
+        PluginSettingsProvider settings = new PluginSettingsProvider(
+            PluginSettings.from(Map.of())
+        );
+
+        new BaseNavigationController(server, stateManager, settings).run();
+
+        verify(player, never()).spawnParticle(
+            eq(Particle.END_ROD), any(Location.class), eq(1),
+            eq(0.0), eq(0.0), eq(0.0), eq(0.0)
+        );
+
+        when(player.getLocation()).thenReturn(new Location(world, 35.51, 64.0, 0.5));
+        new BaseNavigationController(server, stateManager, settings).run();
+
+        verify(player, times(settings.current().navigationParticleCount())).spawnParticle(
+            eq(Particle.END_ROD), any(Location.class), eq(1),
+            eq(0.0), eq(0.0), eq(0.0), eq(0.0)
+        );
+    }
+}

src/test/java/games/dmg/spigotbase/BaseNavigationVisibilityTest.java

@@ -0,0 +1,26 @@
+package games.dmg.spigotbase;
+
+import static org.junit.jupiter.api.Assertions.assertFalse;
+import static org.junit.jupiter.api.Assertions.assertTrue;
+
+import java.util.UUID;
+import org.junit.jupiter.api.Test;
+
+final class BaseNavigationVisibilityTest {
+    private static final BaseLocation BASE = new BaseLocation(
+        UUID.randomUUID(), "world", 0, 64, 0, 0, 0
+    );
+
+    @Test
+    void hidesNavigationAtAndWithinTwentyFiveBlocksBeyondBorder() {
+        assertFalse(BaseNavigationVisibility.isBeyondBorderBuffer(BASE, 10, 35.5, 0.5));
+        assertFalse(BaseNavigationVisibility.isBeyondBorderBuffer(BASE, 10, 20.5, 0.5));
+    }
+
+    @Test
+    void showsNavigationMoreThanTwentyFiveBlocksBeyondCurrentBorder() {
+        assertTrue(BaseNavigationVisibility.isBeyondBorderBuffer(BASE, 10, 35.51, 0.5));
+        assertFalse(BaseNavigationVisibility.isBeyondBorderBuffer(BASE, 75, 100.5, 0.5));
+        assertTrue(BaseNavigationVisibility.isBeyondBorderBuffer(BASE, 75, 100.51, 0.5));
+    }
+}

src/test/java/games/dmg/spigotbase/BaseProgressListenerTest.java

@@ -0,0 +1,66 @@
+package games.dmg.spigotbase;
+
+import static org.junit.jupiter.api.Assertions.assertEquals;
+import static org.mockito.ArgumentMatchers.any;
+import static org.mockito.ArgumentMatchers.anyString;
+import static org.mockito.Mockito.mock;
+import static org.mockito.Mockito.when;
+
+import java.util.Map;
+import java.util.UUID;
+import java.util.concurrent.atomic.AtomicReference;
+import java.util.function.UnaryOperator;
+import org.bukkit.GameMode;
+import org.bukkit.World;
+import org.bukkit.block.Block;
+import org.bukkit.entity.Player;
+import org.bukkit.event.block.BlockPlaceEvent;
+import org.bukkit.plugin.Plugin;
+import org.junit.jupiter.api.Test;
+
+final class BaseProgressListenerTest {
+    @Test
+    void survivalPlacementOutsideBaseCountsTowardOverlayUnlock() {
+        UUID playerId = UUID.randomUUID();
+        PlayerState current = PlayerState.newPlayer(playerId, "Builder");
+        AtomicReference<PlayerState> updated = new AtomicReference<>();
+        BaseStateManager stateManager = mock(BaseStateManager.class);
+        when(stateManager.player(playerId, "Builder")).thenReturn(current);
+        when(stateManager.update(any(), anyString(), any())).thenAnswer(invocation -> {
+            @SuppressWarnings("unchecked")
+            UnaryOperator<PlayerState> operation = invocation.getArgument(2);
+            PlayerState result = operation.apply(current);
+            updated.set(result);
+            return result;
+        });
+        Player player = mock(Player.class);
+        when(player.getUniqueId()).thenReturn(playerId);
+        when(player.getName()).thenReturn("Builder");
+        when(player.getGameMode()).thenReturn(GameMode.SURVIVAL);
+        World world = mock(World.class);
+        when(world.getUID()).thenReturn(UUID.randomUUID());
+        Block block = mock(Block.class);
+        when(block.getWorld()).thenReturn(world);
+        BlockPlaceEvent event = mock(BlockPlaceEvent.class);
+        when(event.getPlayer()).thenReturn(player);
+        when(event.getBlockPlaced()).thenReturn(block);
+        PluginSettingsProvider settings = new PluginSettingsProvider(
+            PluginSettings.from(Map.of())
+        );
+        BaseProgressListener listener = new BaseProgressListener(
+            mock(Plugin.class),
+            stateManager,
+            mock(BaseProgressionService.class),
+            mock(SecondaryProgressionService.class),
+            mock(TeleportProgressionService.class),
+            new SpawnableOverlayProgressionService(settings),
+            new BaseBoundsService(settings),
+            settings
+        );
+
+        listener.onBlockPlace(event);
+
+        assertEquals(1, updated.get().totalBlocksPlaced());
+        assertEquals(0, updated.get().blocksPlacedInBase());
+    }
+}

src/test/java/games/dmg/spigotbase/BaseSettingsCommandTest.java

@@ -6,10 +6,12 @@ import static org.junit.jupiter.api.Assertions.assertTrue;
 import static org.mockito.ArgumentMatchers.any;
 import static org.mockito.ArgumentMatchers.anyString;
 import static org.mockito.Mockito.mock;
+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.io.IOException;
 import java.time.Instant;
 import java.util.List;
 import java.util.Map;
@@ -22,8 +24,40 @@ import org.bukkit.entity.Player;
 import org.bukkit.inventory.ItemStack;
 import org.bukkit.inventory.PlayerInventory;
 import org.junit.jupiter.api.Test;
+import org.mockito.ArgumentCaptor;
 
 final class BaseSettingsCommandTest {
+    @Test
+    void spawnableEnableIsIdempotentAfterUnlock() {
+        UUID playerId = UUID.randomUUID();
+        PlayerState current = PlayerState.newPlayer(playerId, "Builder")
+            .withAdministrativeLevels(1, 0, 0, 0, 0, false, false, false)
+            .withBase(
+                new BaseLocation(UUID.randomUUID(), "world", 0, 64, 0, 0, 0),
+                Instant.EPOCH
+            )
+            .withTotalBlocksPlaced(250);
+
+        CommandResult result = execute(current, "spawnable", "enable");
+
+        assertTrue(result.updated().spawnableOverlayEnabled());
+    }
+
+    @Test
+    void borderEnableIsIdempotent() {
+        UUID playerId = UUID.randomUUID();
+        PlayerState current = PlayerState.newPlayer(playerId, "Builder")
+            .withAdministrativeLevels(1, 0, 0, 0, 0, false, false, false)
+            .withBase(
+                new BaseLocation(UUID.randomUUID(), "world", 0, 64, 0, 0, 0),
+                Instant.EPOCH
+            );
+
+        CommandResult result = execute(current, "border", "enable");
+
+        assertTrue(result.updated().borderEnabled());
+    }
+
     @Test
     void invalidArgumentsShowUsage() {
         UUID playerId = UUID.randomUUID();
@@ -58,7 +92,21 @@ final class BaseSettingsCommandTest {
             List.of("allowed"),
             command.onTabComplete(null, null, "basesettings", new String[] {"visitors", "a"})
         );
-        for (String setting : List.of("navigation", "flight", "bossbar")) {
+        assertEquals(
+            List.of("upgrade"),
+            command.onTabComplete(null, null, "basesettings", new String[] {"pocket", "u"})
+        );
+        assertEquals(
+            List.of("mobs"),
+            command.onTabComplete(null, null, "basesettings", new String[] {"pocket", "m"})
+        );
+        assertEquals(
+            List.of("enable"),
+            command.onTabComplete(
+                null, null, "basesettings", new String[] {"pocket", "mobs", "e"}
+            )
+        );
+        for (String setting : List.of("navigation", "flight", "border", "spawnable", "bossbar")) {
             assertEquals(
                 List.of("disable"),
                 command.onTabComplete(null, null, "basesettings", new String[] {setting, "d"})
@@ -75,7 +123,10 @@ final class BaseSettingsCommandTest {
         );
 
         assertEquals(
-            List.of("status", "upgrade", "visitors", "navigation", "flight", "bossbar"),
+            List.of(
+                "status", "upgrade", "pocket", "visitors", "navigation", "flight", "border",
+                "spawnable", "bossbar"
+            ),
             command.onTabComplete(null, null, "basesettings", new String[] {""})
         );
     }
@@ -121,6 +172,204 @@ final class BaseSettingsCommandTest {
         assertTrue(updated.get().visitorsEnabled());
     }
 
+    @Test
+    void pocketUpgradePurchasesFirstLevelAfterBaseIv() throws Exception {
+        UUID playerId = UUID.randomUUID();
+        Player player = mock(Player.class);
+        when(player.getUniqueId()).thenReturn(playerId);
+        when(player.getName()).thenReturn("Builder");
+        PlayerInventory inventory = mock(PlayerInventory.class);
+        when(player.getInventory()).thenReturn(inventory);
+        when(inventory.getStorageContents()).thenReturn(new ItemStack[] {
+            new ItemStack(Material.DIAMOND_BLOCK, 64)
+        });
+        PlayerState owner = PlayerState.newPlayer(playerId, "Builder")
+            .withAdministrativeLevels(4, 0, 0, 0, 0, false, false, true)
+            .withBase(
+                new BaseLocation(UUID.randomUUID(), "world", 0, 64, 0, 0, 0),
+                Instant.EPOCH
+            );
+        BaseStateManager stateManager = mock(BaseStateManager.class);
+        when(stateManager.player(playerId, "Builder")).thenReturn(owner);
+        PocketBaseManager pocketBases = mock(PocketBaseManager.class);
+        when(pocketBases.state(playerId)).thenReturn(PocketBaseState.locked(playerId));
+        when(pocketBases.upgrade(playerId)).thenReturn(
+            new PocketBaseState(playerId, 1, java.util.Optional.empty())
+        );
+        BaseSettingsCommand command = new BaseSettingsCommand(
+            stateManager,
+            new PluginSettingsProvider(PluginSettings.from(Map.of())),
+            mock(BaseFlightController.class),
+            pocketBases
+        );
+
+        command.onCommand(player, null, "basesettings", new String[] {"pocket", "upgrade"});
+
+        verify(pocketBases).upgrade(playerId);
+        verify(inventory).setStorageContents(any(ItemStack[].class));
+    }
+
+    @Test
+    void pocketOwnerCanEnableNaturalMobSpawning() throws Exception {
+        UUID playerId = UUID.randomUUID();
+        Player player = mock(Player.class);
+        when(player.getUniqueId()).thenReturn(playerId);
+        when(player.getName()).thenReturn("Builder");
+        BaseStateManager stateManager = mock(BaseStateManager.class);
+        when(stateManager.player(playerId, "Builder"))
+            .thenReturn(PlayerState.newPlayer(playerId, "Builder"));
+        PocketBaseManager pocketBases = mock(PocketBaseManager.class);
+        when(pocketBases.state(playerId)).thenReturn(
+            new PocketBaseState(playerId, 1, java.util.Optional.empty(), false)
+        );
+        when(pocketBases.setMobSpawning(playerId, true)).thenReturn(
+            new PocketBaseState(playerId, 1, java.util.Optional.empty(), true)
+        );
+        BaseSettingsCommand command = new BaseSettingsCommand(
+            stateManager,
+            new PluginSettingsProvider(PluginSettings.from(Map.of())),
+            mock(BaseFlightController.class),
+            pocketBases
+        );
+
+        command.onCommand(
+            player, null, "basesettings", new String[] {"pocket", "mobs", "enable"}
+        );
+
+        verify(pocketBases).setMobSpawning(playerId, true);
+        verify(player).sendMessage(org.mockito.ArgumentMatchers.<String>argThat(
+            message -> message.contains("mob spawning") && message.contains("enabled")
+        ));
+    }
+
+    @Test
+    void failedPocketMobSpawningChangeReportsOnlyFailure() throws Exception {
+        UUID playerId = UUID.randomUUID();
+        Player player = mock(Player.class);
+        when(player.getUniqueId()).thenReturn(playerId);
+        when(player.getName()).thenReturn("Builder");
+        BaseStateManager stateManager = mock(BaseStateManager.class);
+        when(stateManager.player(playerId, "Builder"))
+            .thenReturn(PlayerState.newPlayer(playerId, "Builder"));
+        PocketBaseManager pocketBases = mock(PocketBaseManager.class);
+        when(pocketBases.state(playerId)).thenReturn(
+            new PocketBaseState(playerId, 1, java.util.Optional.empty(), false)
+        );
+        when(pocketBases.setMobSpawning(playerId, true))
+            .thenThrow(new IOException("save failed"));
+        BaseSettingsCommand command = new BaseSettingsCommand(
+            stateManager,
+            new PluginSettingsProvider(PluginSettings.from(Map.of())),
+            mock(BaseFlightController.class),
+            pocketBases
+        );
+
+        command.onCommand(
+            player, null, "basesettings", new String[] {"pocket", "mobs", "enable"}
+        );
+
+        verify(player).sendMessage(org.mockito.ArgumentMatchers.<String>argThat(
+            message -> message.contains("could not be changed")
+        ));
+        verify(player, never()).sendMessage(org.mockito.ArgumentMatchers.<String>argThat(
+            message -> message.contains("is now")
+        ));
+    }
+
+    @Test
+    void lockedPlayerCannotEnablePocketMobSpawning() throws Exception {
+        UUID playerId = UUID.randomUUID();
+        Player player = mock(Player.class);
+        when(player.getUniqueId()).thenReturn(playerId);
+        when(player.getName()).thenReturn("Builder");
+        BaseStateManager stateManager = mock(BaseStateManager.class);
+        when(stateManager.player(playerId, "Builder"))
+            .thenReturn(PlayerState.newPlayer(playerId, "Builder"));
+        PocketBaseManager pocketBases = mock(PocketBaseManager.class);
+        when(pocketBases.state(playerId)).thenReturn(PocketBaseState.locked(playerId));
+        BaseSettingsCommand command = new BaseSettingsCommand(
+            stateManager,
+            new PluginSettingsProvider(PluginSettings.from(Map.of())),
+            mock(BaseFlightController.class),
+            pocketBases
+        );
+
+        command.onCommand(
+            player, null, "basesettings", new String[] {"pocket", "mobs", "enable"}
+        );
+
+        verify(pocketBases, never()).setMobSpawning(playerId, true);
+        verify(player).sendMessage(org.mockito.ArgumentMatchers.<String>argThat(
+            message -> message.contains("Pocket Base I") && message.contains("locked")
+        ));
+    }
+
+    @Test
+    void failedPocketUpgradeRestoresPayment() throws Exception {
+        UUID playerId = UUID.randomUUID();
+        Player player = mock(Player.class);
+        when(player.getUniqueId()).thenReturn(playerId);
+        when(player.getName()).thenReturn("Builder");
+        PlayerInventory inventory = mock(PlayerInventory.class);
+        when(player.getInventory()).thenReturn(inventory);
+        when(inventory.getStorageContents()).thenReturn(new ItemStack[] {
+            new ItemStack(Material.DIAMOND_BLOCK, 64)
+        });
+        PlayerState owner = PlayerState.newPlayer(playerId, "Builder")
+            .withAdministrativeLevels(4, 0, 0, 0, 0, false, false, true)
+            .withBase(
+                new BaseLocation(UUID.randomUUID(), "world", 0, 64, 0, 0, 0),
+                Instant.EPOCH
+            );
+        BaseStateManager stateManager = mock(BaseStateManager.class);
+        when(stateManager.player(playerId, "Builder")).thenReturn(owner);
+        PocketBaseManager pocketBases = mock(PocketBaseManager.class);
+        when(pocketBases.state(playerId)).thenReturn(PocketBaseState.locked(playerId));
+        when(pocketBases.upgrade(playerId)).thenThrow(new IOException("save failed"));
+        BaseSettingsCommand command = new BaseSettingsCommand(
+            stateManager,
+            new PluginSettingsProvider(PluginSettings.from(Map.of())),
+            mock(BaseFlightController.class),
+            pocketBases
+        );
+
+        command.onCommand(player, null, "basesettings", new String[] {"pocket", "upgrade"});
+
+        ArgumentCaptor<ItemStack[]> contents = ArgumentCaptor.forClass(ItemStack[].class);
+        verify(inventory, times(2)).setStorageContents(contents.capture());
+        ItemStack[] restored = contents.getAllValues().get(1);
+        assertEquals(Material.DIAMOND_BLOCK, restored[0].getType());
+        assertEquals(64, restored[0].getAmount());
+    }
+
+    @Test
+    void statusDisplaysPocketMobSpawningPreference() {
+        UUID playerId = UUID.randomUUID();
+        Player player = mock(Player.class);
+        when(player.getUniqueId()).thenReturn(playerId);
+        when(player.getName()).thenReturn("Builder");
+        BaseStateManager stateManager = mock(BaseStateManager.class);
+        when(stateManager.player(playerId, "Builder"))
+            .thenReturn(PlayerState.newPlayer(playerId, "Builder"));
+        PocketBaseManager pocketBases = mock(PocketBaseManager.class);
+        when(pocketBases.state(playerId)).thenReturn(
+            new PocketBaseState(playerId, 1, java.util.Optional.empty(), false)
+        );
+        BaseSettingsCommand command = new BaseSettingsCommand(
+            stateManager,
+            new PluginSettingsProvider(PluginSettings.from(Map.of())),
+            mock(BaseFlightController.class),
+            pocketBases
+        );
+
+        command.onCommand(player, null, "basesettings", new String[] {"status"});
+
+        verify(player).sendMessage(org.mockito.ArgumentMatchers.<String>argThat(
+            message -> message.contains("Pocket Base 1")
+                && message.contains("mob spawning=disabled")
+        ));
+    }
+
     @Test
     void bossbarEnableIsIdempotent() {
         UUID playerId = UUID.randomUUID();
@@ -189,11 +438,20 @@ final class BaseSettingsCommandTest {
         command.onCommand(player, null, "basesettings", new String[] {"status"});
 
         verify(player, times(2)).sendMessage(ChatColor.GOLD + "=== Base Progress ===");
+        verify(player, times(2)).sendMessage(
+            org.mockito.ArgumentMatchers.<String>argThat(message ->
+                message.contains("Spawnable Overlay:")
+                    && message.contains("0/250 placements")
+                    && message.contains("locked")
+            )
+        );
         verify(player, times(2)).sendMessage(
             org.mockito.ArgumentMatchers.<String>argThat(message ->
             message.contains("Settings: visitors=")
                 && message.contains("navigation=")
                 && message.contains("flight=")
+                && message.contains("border=")
+                && message.contains("spawnable=")
                 && message.contains("bossbar=")
             )
         );

src/test/java/games/dmg/spigotbase/BaseTeleportManagerTest.java

@@ -0,0 +1,64 @@
+package games.dmg.spigotbase;
+
+import static org.mockito.ArgumentMatchers.any;
+import static org.mockito.ArgumentMatchers.eq;
+import static org.mockito.Mockito.mock;
+import static org.mockito.Mockito.verify;
+import static org.mockito.Mockito.verifyNoInteractions;
+import static org.mockito.Mockito.when;
+
+import java.time.Clock;
+import java.time.Duration;
+import java.time.Instant;
+import java.util.Optional;
+import java.util.UUID;
+import org.bukkit.ChatColor;
+import org.bukkit.World;
+import org.bukkit.entity.Player;
+import org.bukkit.plugin.Plugin;
+import org.junit.jupiter.api.Test;
+
+final class BaseTeleportManagerTest {
+    @Test
+    void visitFromAnotherWorldIsRejectedBeforeWarmupAndCooldownChecks() {
+        UUID visitorId = UUID.randomUUID();
+        UUID ownerId = UUID.randomUUID();
+        UUID baseWorldId = UUID.randomUUID();
+        BaseStateManager stateManager = mock(BaseStateManager.class);
+        TeleportPolicy teleportPolicy = mock(TeleportPolicy.class);
+        VisitorPolicy visitorPolicy = mock(VisitorPolicy.class);
+        Player visitor = mock(Player.class);
+        World visitorWorld = mock(World.class);
+        PlayerState owner = PlayerState.newPlayer(ownerId, "Owner")
+            .withGrassAndDirtProgress(500, 4)
+            .withBase(
+                new BaseLocation(baseWorldId, "world", 0, 64, 0, 0, 0),
+                Instant.EPOCH
+            )
+            .withVisitorsEnabled(true);
+        PlayerState visitorState = PlayerState.newPlayer(visitorId, "Visitor");
+        BaseTeleportManager manager = new BaseTeleportManager(
+            mock(Plugin.class),
+            stateManager,
+            teleportPolicy,
+            visitorPolicy,
+            mock(SafeBaseDestination.class),
+            Clock.systemUTC()
+        );
+
+        when(visitor.getUniqueId()).thenReturn(visitorId);
+        when(visitor.getName()).thenReturn("Visitor");
+        when(visitor.getWorld()).thenReturn(visitorWorld);
+        when(visitorWorld.getUID()).thenReturn(UUID.randomUUID());
+        when(stateManager.player(visitorId, "Visitor")).thenReturn(visitorState);
+        when(visitorPolicy.remaining(eq(visitorState), eq(ownerId), any()))
+            .thenReturn(Optional.of(Duration.ofSeconds(1)));
+
+        manager.startVisit(visitor, owner);
+
+        verify(visitor).sendMessage(
+            ChatColor.RED + "You must be in the same dimension as that base to visit it."
+        );
+        verifyNoInteractions(stateManager, teleportPolicy, visitorPolicy);
+    }
+}

src/test/java/games/dmg/spigotbase/PlayerStateTest.java

@@ -1,13 +1,48 @@
 package games.dmg.spigotbase;
 
+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.time.Instant;
 import java.util.Map;
 import java.util.Optional;
 import java.util.UUID;
 import org.junit.jupiter.api.Test;
 
 final class PlayerStateTest {
+    @Test
+    void spawnableOverlayProgressAndPreferenceCanBeUpdated() {
+        PlayerState player = PlayerState.newPlayer(UUID.randomUUID(), "Alex")
+            .withAdministrativeLevels(1, 0, 0, 0, 0, false, false, false)
+            .withBase(
+                new BaseLocation(UUID.randomUUID(), "world", 0, 64, 0, 0, 0),
+                Instant.EPOCH
+            );
+
+        PlayerState updated = player
+            .withTotalBlocksPlaced(250)
+            .withSpawnableOverlayEnabled(true);
+
+        assertTrue(updated.spawnableOverlayEnabled());
+        assertTrue(updated.totalBlocksPlaced() == 250);
+    }
+
+    @Test
+    void borderVisualizationIsDisabledByDefaultAndCanBeEnabled() {
+        UUID playerId = UUID.randomUUID();
+        PlayerState player = PlayerState.newPlayer(playerId, "Alex");
+        PlayerState established = player
+            .withAdministrativeLevels(1, 0, 0, 0, 0, false, false, false)
+            .withBase(
+                new BaseLocation(UUID.randomUUID(), "world", 0, 64, 0, 0, 0),
+                Instant.EPOCH
+            );
+
+        assertFalse(player.borderEnabled());
+        assertTrue(established.withBorderEnabled(true).borderEnabled());
+    }
+
     @Test
     void rejectsLevelsOutsideKnownRanges() {
         UUID playerId = UUID.randomUUID();

src/test/java/games/dmg/spigotbase/PluginSettingsTest.java

@@ -18,8 +18,28 @@ final class PluginSettingsTest {
         assertEquals(86_400L, settings.relocationCooldownSeconds());
         assertEquals(5, settings.flightWarningBuffer());
         assertEquals(200, settings.teleportUnlockPlacements());
+        assertEquals(250, settings.spawnableOverlayUnlockPlacements());
         assertEquals(10_800L, settings.initialTeleportCooldownSeconds());
         assertEquals(128, settings.visitorUnlockDiamondCost());
+        assertEquals(64, settings.pocketBaseUnlockCost());
+        assertEquals(16, settings.pocketBaseUpgradeCost());
+        assertEquals("DIAMOND_BLOCK", settings.pocketBaseCurrencyMaterial());
+        assertEquals("DIAMOND_BLOCK", settings.pocketBasePortalFrameMaterial());
+    }
+
+    @Test
+    void pocketBaseCostsAndMaterialsAreConfigurable() {
+        PluginSettings settings = PluginSettings.from(Map.of(
+            "pocket-base-unlock-cost", 32,
+            "pocket-base-upgrade-cost", 8,
+            "pocket-base-currency-material", "EMERALD_BLOCK",
+            "pocket-base-portal-frame-material", "GOLD_BLOCK"
+        ));
+
+        assertEquals(32, settings.pocketBaseUnlockCost());
+        assertEquals(8, settings.pocketBaseUpgradeCost());
+        assertEquals("EMERALD_BLOCK", settings.pocketBaseCurrencyMaterial());
+        assertEquals("GOLD_BLOCK", settings.pocketBasePortalFrameMaterial());
     }
 
     @Test

src/test/java/games/dmg/spigotbase/PocketBaseControllerTest.java

@@ -0,0 +1,245 @@
+package games.dmg.spigotbase;
+
+import static org.mockito.ArgumentMatchers.anyInt;
+import static org.mockito.Mockito.mock;
+import static org.mockito.Mockito.never;
+import static org.mockito.Mockito.verify;
+import static org.mockito.Mockito.when;
+
+import java.time.Instant;
+import java.util.HashSet;
+import java.util.Map;
+import java.util.Optional;
+import java.util.Set;
+import java.util.UUID;
+import java.util.logging.Logger;
+import org.bukkit.Material;
+import org.bukkit.Server;
+import org.bukkit.World;
+import org.bukkit.block.Block;
+import org.bukkit.entity.Player;
+import org.bukkit.event.block.Action;
+import org.bukkit.event.block.BlockPlaceEvent;
+import org.bukkit.event.player.PlayerInteractEvent;
+import org.bukkit.inventory.ItemStack;
+import org.junit.jupiter.api.Test;
+
+final class PocketBaseControllerTest {
+    @Test
+    void ownerCanActivateCompleteFrameInsideNormalBase() throws Exception {
+        UUID ownerId = UUID.randomUUID();
+        UUID worldId = UUID.randomUUID();
+        PocketPortalLocation portal = new PocketPortalLocation(
+            worldId, "world", -2, 64, 0, PocketPortalAxis.X
+        );
+        Set<BlockPosition> frame = new HashSet<>(PocketPortalGeometry.frameBlocks(portal));
+        Player owner = mock(Player.class);
+        World world = mock(World.class);
+        Block clicked = block(world, -2, 66, 0, Material.DIAMOND_BLOCK);
+        PlayerInteractEvent event = mock(PlayerInteractEvent.class);
+        BaseStateManager baseStates = mock(BaseStateManager.class);
+        PocketBaseManager pocketBases = mock(PocketBaseManager.class);
+        PluginSettings settings = PluginSettings.from(Map.of());
+        PlayerState ownerState = PlayerState.newPlayer(ownerId, "Owner")
+            .withAdministrativeLevels(4, 0, 0, 0, 0, false, false, true)
+            .withBase(new BaseLocation(worldId, "world", 0, 64, 0, 0, 0), Instant.EPOCH);
+
+        when(owner.getUniqueId()).thenReturn(ownerId);
+        when(owner.getName()).thenReturn("Owner");
+        when(event.getPlayer()).thenReturn(owner);
+        when(event.getAction()).thenReturn(Action.RIGHT_CLICK_BLOCK);
+        when(event.getClickedBlock()).thenReturn(clicked);
+        when(event.getItem()).thenReturn(new ItemStack(Material.FLINT_AND_STEEL));
+        when(world.getUID()).thenReturn(worldId);
+        when(world.getName()).thenReturn("world");
+        when(world.getBlockAt(anyInt(), anyInt(), anyInt())).thenAnswer(invocation -> {
+            BlockPosition position = new BlockPosition(
+                invocation.getArgument(0), invocation.getArgument(1), invocation.getArgument(2)
+            );
+            return block(
+                world,
+                position.x(),
+                position.y(),
+                position.z(),
+                frame.contains(position) ? Material.DIAMOND_BLOCK : Material.AIR
+            );
+        });
+        when(baseStates.player(ownerId, "Owner")).thenReturn(ownerState);
+        when(pocketBases.state(ownerId)).thenReturn(
+            new PocketBaseState(ownerId, 1, Optional.empty())
+        );
+        when(pocketBases.activateEntrance(ownerId, portal)).thenReturn(
+            new PocketBaseState(ownerId, 1, Optional.of(portal))
+        );
+        PocketBaseController controller = new PocketBaseController(
+            mock(Server.class),
+            baseStates,
+            new BaseBoundsService(settings),
+            pocketBases,
+            new PluginSettingsProvider(settings),
+            Logger.getAnonymousLogger()
+        );
+
+        controller.onActivate(event);
+
+        verify(pocketBases).activateEntrance(ownerId, portal);
+        verify(event).setCancelled(true);
+    }
+
+    @Test
+    void ownerCanActivateCompleteReturnFrameInsideOwnPocketBase() throws Exception {
+        UUID ownerId = UUID.randomUUID();
+        UUID worldId = UUID.randomUUID();
+        PocketPortalLocation portal = new PocketPortalLocation(
+            worldId, "pocket", 8, 65, 8, PocketPortalAxis.X
+        );
+        Set<BlockPosition> frame = new HashSet<>(PocketPortalGeometry.frameBlocks(portal));
+        Player owner = mock(Player.class);
+        World world = mock(World.class);
+        Block clicked = block(world, 8, 67, 8, Material.DIAMOND_BLOCK);
+        PlayerInteractEvent event = mock(PlayerInteractEvent.class);
+        PocketBaseManager pocketBases = mock(PocketBaseManager.class);
+        PluginSettings settings = PluginSettings.from(Map.of());
+
+        when(owner.getUniqueId()).thenReturn(ownerId);
+        when(event.getPlayer()).thenReturn(owner);
+        when(event.getAction()).thenReturn(Action.RIGHT_CLICK_BLOCK);
+        when(event.getClickedBlock()).thenReturn(clicked);
+        when(event.getItem()).thenReturn(new ItemStack(Material.FLINT_AND_STEEL));
+        when(world.getUID()).thenReturn(worldId);
+        when(world.getName()).thenReturn("pocket");
+        when(world.getBlockAt(anyInt(), anyInt(), anyInt())).thenAnswer(invocation -> {
+            BlockPosition position = new BlockPosition(
+                invocation.getArgument(0), invocation.getArgument(1), invocation.getArgument(2)
+            );
+            return block(
+                world,
+                position.x(),
+                position.y(),
+                position.z(),
+                frame.contains(position) ? Material.DIAMOND_BLOCK : Material.AIR
+            );
+        });
+        when(pocketBases.ownerForPocketWorld(worldId)).thenReturn(Optional.of(ownerId));
+        when(pocketBases.state(ownerId)).thenReturn(
+            new PocketBaseState(ownerId, 1, Optional.empty())
+        );
+        when(pocketBases.policy()).thenReturn(new PocketBasePolicy(settings));
+        PocketBaseController controller = new PocketBaseController(
+            mock(Server.class),
+            mock(BaseStateManager.class),
+            new BaseBoundsService(settings),
+            pocketBases,
+            new PluginSettingsProvider(settings),
+            Logger.getAnonymousLogger()
+        );
+
+        controller.onActivate(event);
+
+        verify(pocketBases).activateReturnPortal(ownerId, portal);
+        verify(event).setCancelled(true);
+    }
+
+    @Test
+    void returnFrameOutsideUnlockedPocketBoundaryIsRejected() throws Exception {
+        UUID ownerId = UUID.randomUUID();
+        UUID worldId = UUID.randomUUID();
+        PocketPortalLocation portal = new PocketPortalLocation(
+            worldId, "pocket", 30, 65, 8, PocketPortalAxis.X
+        );
+        Set<BlockPosition> frame = new HashSet<>(PocketPortalGeometry.frameBlocks(portal));
+        Player owner = mock(Player.class);
+        World world = mock(World.class);
+        Block clicked = block(world, 30, 67, 8, Material.DIAMOND_BLOCK);
+        PlayerInteractEvent event = mock(PlayerInteractEvent.class);
+        PocketBaseManager pocketBases = mock(PocketBaseManager.class);
+        PluginSettings settings = PluginSettings.from(Map.of());
+
+        when(owner.getUniqueId()).thenReturn(ownerId);
+        when(event.getPlayer()).thenReturn(owner);
+        when(event.getAction()).thenReturn(Action.RIGHT_CLICK_BLOCK);
+        when(event.getClickedBlock()).thenReturn(clicked);
+        when(event.getItem()).thenReturn(new ItemStack(Material.FLINT_AND_STEEL));
+        when(world.getUID()).thenReturn(worldId);
+        when(world.getName()).thenReturn("pocket");
+        when(world.getBlockAt(anyInt(), anyInt(), anyInt())).thenAnswer(invocation -> {
+            BlockPosition position = new BlockPosition(
+                invocation.getArgument(0), invocation.getArgument(1), invocation.getArgument(2)
+            );
+            return block(
+                world,
+                position.x(),
+                position.y(),
+                position.z(),
+                frame.contains(position) ? Material.DIAMOND_BLOCK : Material.AIR
+            );
+        });
+        when(pocketBases.ownerForPocketWorld(worldId)).thenReturn(Optional.of(ownerId));
+        when(pocketBases.state(ownerId)).thenReturn(
+            new PocketBaseState(ownerId, 1, Optional.empty())
+        );
+        when(pocketBases.policy()).thenReturn(new PocketBasePolicy(settings));
+        PocketBaseController controller = new PocketBaseController(
+            mock(Server.class),
+            mock(BaseStateManager.class),
+            new BaseBoundsService(settings),
+            pocketBases,
+            new PluginSettingsProvider(settings),
+            Logger.getAnonymousLogger()
+        );
+
+        controller.onActivate(event);
+
+        verify(pocketBases, never()).activateReturnPortal(ownerId, portal);
+        verify(event).setCancelled(true);
+    }
+
+    @Test
+    void placementOutsideUnlockedPocketBoundaryIsCancelled() {
+        UUID ownerId = UUID.randomUUID();
+        UUID worldId = UUID.randomUUID();
+        World world = mock(World.class);
+        Block placed = block(world, 32, 65, 0, Material.STONE);
+        Player player = mock(Player.class);
+        BlockPlaceEvent event = mock(BlockPlaceEvent.class);
+        PocketBaseManager pocketBases = mock(PocketBaseManager.class);
+        PluginSettings settings = PluginSettings.from(Map.of());
+
+        when(world.getUID()).thenReturn(worldId);
+        when(event.getBlockPlaced()).thenReturn(placed);
+        when(event.getPlayer()).thenReturn(player);
+        when(pocketBases.ownerForPocketWorld(worldId)).thenReturn(Optional.of(ownerId));
+        when(pocketBases.state(ownerId)).thenReturn(
+            new PocketBaseState(ownerId, 1, Optional.empty())
+        );
+        when(pocketBases.policy()).thenReturn(new PocketBasePolicy(settings));
+        PocketBaseController controller = new PocketBaseController(
+            mock(Server.class),
+            mock(BaseStateManager.class),
+            new BaseBoundsService(settings),
+            pocketBases,
+            new PluginSettingsProvider(settings),
+            Logger.getAnonymousLogger()
+        );
+
+        controller.onPlace(event);
+
+        verify(event).setCancelled(true);
+    }
+
+    private static Block block(
+        World world,
+        int x,
+        int y,
+        int z,
+        Material material
+    ) {
+        Block block = mock(Block.class);
+        when(block.getWorld()).thenReturn(world);
+        when(block.getX()).thenReturn(x);
+        when(block.getY()).thenReturn(y);
+        when(block.getZ()).thenReturn(z);
+        when(block.getType()).thenReturn(material);
+        return block;
+    }
+}

src/test/java/games/dmg/spigotbase/PocketBaseManagerTest.java

@@ -0,0 +1,108 @@
+package games.dmg.spigotbase;
+
+import static org.junit.jupiter.api.Assertions.assertEquals;
+import static org.junit.jupiter.api.Assertions.assertThrows;
+import static org.mockito.Mockito.inOrder;
+import static org.mockito.Mockito.mock;
+import static org.mockito.Mockito.verify;
+import static org.mockito.Mockito.when;
+
+import java.io.IOException;
+import java.util.Map;
+import java.util.Optional;
+import java.util.UUID;
+import java.util.function.UnaryOperator;
+import org.junit.jupiter.api.Test;
+import org.mockito.InOrder;
+
+final class PocketBaseManagerTest {
+    @Test
+    void relocatedReturnPortalOverridesGeneratedDefault() {
+        UUID ownerId = UUID.randomUUID();
+        PocketPortalLocation relocated = new PocketPortalLocation(
+            UUID.randomUUID(), "pocket", 20, 65, 12, PocketPortalAxis.Z
+        );
+        PocketBaseStateManager states = mock(PocketBaseStateManager.class);
+        PocketBaseWorldService worlds = mock(PocketBaseWorldService.class);
+        when(states.state(ownerId)).thenReturn(new PocketBaseState(
+            ownerId, 1, Optional.empty(), Optional.of(relocated), false
+        ));
+        PocketBaseManager manager = new PocketBaseManager(
+            states,
+            worlds,
+            new PluginSettingsProvider(PluginSettings.from(Map.of()))
+        );
+
+        assertEquals(relocated, manager.returnPortal(ownerId));
+    }
+
+    @Test
+    void existingStateWithoutRelocationUsesGeneratedReturnPortal() {
+        UUID ownerId = UUID.randomUUID();
+        PocketPortalLocation generated = new PocketPortalLocation(
+            UUID.randomUUID(), "pocket", -2, 65, 0, PocketPortalAxis.X
+        );
+        PocketBaseStateManager states = mock(PocketBaseStateManager.class);
+        PocketBaseWorldService worlds = mock(PocketBaseWorldService.class);
+        when(states.state(ownerId)).thenReturn(
+            new PocketBaseState(ownerId, 1, Optional.empty())
+        );
+        when(worlds.returnPortal(ownerId)).thenReturn(generated);
+        PocketBaseManager manager = new PocketBaseManager(
+            states,
+            worlds,
+            new PluginSettingsProvider(PluginSettings.from(Map.of()))
+        );
+
+        assertEquals(generated, manager.returnPortal(ownerId));
+    }
+
+    @Test
+    void persistsAndAppliesMobSpawningPreference() throws Exception {
+        UUID ownerId = UUID.randomUUID();
+        PocketBaseState current = new PocketBaseState(ownerId, 1, Optional.empty(), false);
+        PocketBaseStateManager states = mock(PocketBaseStateManager.class);
+        PocketBaseWorldService worlds = mock(PocketBaseWorldService.class);
+        when(states.state(ownerId)).thenReturn(current);
+        when(states.updateAndSave(org.mockito.ArgumentMatchers.eq(ownerId),
+            org.mockito.ArgumentMatchers.any())).thenAnswer(invocation -> {
+                @SuppressWarnings("unchecked")
+                UnaryOperator<PocketBaseState> operation = invocation.getArgument(1);
+                return operation.apply(current);
+            });
+        PocketBaseManager manager = new PocketBaseManager(
+            states,
+            worlds,
+            new PluginSettingsProvider(PluginSettings.from(Map.of()))
+        );
+
+        manager.setMobSpawning(ownerId, true);
+
+        InOrder order = inOrder(worlds, states);
+        order.verify(worlds).setMobSpawning(ownerId, true);
+        order.verify(states).updateAndSave(
+            org.mockito.ArgumentMatchers.eq(ownerId), org.mockito.ArgumentMatchers.any()
+        );
+    }
+
+    @Test
+    void restoresWorldSettingWhenPersistenceFails() throws Exception {
+        UUID ownerId = UUID.randomUUID();
+        PocketBaseState current = new PocketBaseState(ownerId, 1, Optional.empty(), false);
+        PocketBaseStateManager states = mock(PocketBaseStateManager.class);
+        PocketBaseWorldService worlds = mock(PocketBaseWorldService.class);
+        when(states.state(ownerId)).thenReturn(current);
+        when(states.updateAndSave(org.mockito.ArgumentMatchers.eq(ownerId),
+            org.mockito.ArgumentMatchers.any())).thenThrow(new IOException("save failed"));
+        PocketBaseManager manager = new PocketBaseManager(
+            states,
+            worlds,
+            new PluginSettingsProvider(PluginSettings.from(Map.of()))
+        );
+
+        assertThrows(IOException.class, () -> manager.setMobSpawning(ownerId, true));
+
+        verify(worlds).setMobSpawning(ownerId, true);
+        verify(worlds).setMobSpawning(ownerId, false);
+    }
+}

src/test/java/games/dmg/spigotbase/PocketBasePolicyTest.java

@@ -0,0 +1,34 @@
+package games.dmg.spigotbase;
+
+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.Map;
+import java.util.UUID;
+import org.junit.jupiter.api.Test;
+
+final class PocketBasePolicyTest {
+    private final PocketBasePolicy policy = new PocketBasePolicy(PluginSettings.from(Map.of()));
+
+    @Test
+    void levelsExpandBySixteenBlocksOnEverySide() {
+        assertEquals(64, policy.size(1));
+        assertEquals(96, policy.size(2));
+        assertEquals(128, policy.size(3));
+    }
+
+    @Test
+    void unlockAndLaterLevelsUseTheirConfiguredPrices() {
+        assertEquals(64, policy.price(PocketBaseState.locked(UUID.randomUUID())));
+        assertEquals(16, policy.price(new PocketBaseState(UUID.randomUUID(), 1, java.util.Optional.empty())));
+    }
+
+    @Test
+    void buildBoundaryMatchesUnlockedPlatform() {
+        assertTrue(policy.contains(1, -32, -32));
+        assertTrue(policy.contains(1, 31, 31));
+        assertFalse(policy.contains(1, -33, 0));
+        assertFalse(policy.contains(1, 32, 0));
+    }
+}

src/test/java/games/dmg/spigotbase/PocketBaseWorldServiceTest.java

@@ -0,0 +1,135 @@
+package games.dmg.spigotbase;
+
+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.never;
+import static org.mockito.Mockito.verify;
+import static org.mockito.Mockito.when;
+
+import java.util.HashMap;
+import java.util.Map;
+import java.util.Optional;
+import java.util.UUID;
+import org.bukkit.Material;
+import org.bukkit.Server;
+import org.bukkit.World;
+import org.bukkit.WorldCreator;
+import org.bukkit.block.Block;
+import org.junit.jupiter.api.Test;
+
+final class PocketBaseWorldServiceTest {
+    @Test
+    void firstLevelGeneratesGrassPlatformAndReturnPortal() {
+        UUID ownerId = UUID.randomUUID();
+        UUID worldId = UUID.randomUUID();
+        Server server = mock(Server.class);
+        World world = mock(World.class);
+        Map<BlockPosition, Block> blocks = blocks(world);
+        when(server.createWorld(any(WorldCreator.class))).thenReturn(world);
+        when(world.getUID()).thenReturn(worldId);
+        when(world.getName()).thenReturn("pocket");
+        PocketBaseWorldService service = new PocketBaseWorldService(
+            server,
+            new PluginSettingsProvider(PluginSettings.from(Map.of()))
+        );
+
+        service.expand(ownerId, 0, 1);
+
+        verify(blocks.get(new BlockPosition(-32, 64, -32)))
+            .setType(Material.GRASS_BLOCK, false);
+        verify(blocks.get(new BlockPosition(31, 61, 31))).setType(Material.DIRT, false);
+        verify(blocks.get(new BlockPosition(-2, 65, 0)))
+            .setType(Material.DIAMOND_BLOCK, false);
+        verify(world).setSpawnLocation(0, 65, 5);
+        verify(world).setSpawnFlags(false, false);
+        assertEquals(ownerId, service.ownerForWorld(worldId).orElseThrow());
+    }
+
+    @Test
+    void checksRelocatedReturnPortalFrameAtItsSavedLocation() {
+        UUID ownerId = UUID.randomUUID();
+        UUID worldId = UUID.randomUUID();
+        Server server = mock(Server.class);
+        World world = mock(World.class);
+        Map<BlockPosition, Block> blocks = blocks(world);
+        when(server.getWorld(org.mockito.ArgumentMatchers.anyString())).thenReturn(world);
+        when(world.getUID()).thenReturn(worldId);
+        PocketPortalLocation portal = new PocketPortalLocation(
+            worldId, "pocket", 20, 65, 12, PocketPortalAxis.Z
+        );
+        for (BlockPosition position : PocketPortalGeometry.frameBlocks(portal)) {
+            when(world.getBlockAt(position.x(), position.y(), position.z()).getType())
+                .thenReturn(Material.DIAMOND_BLOCK);
+        }
+        PocketBaseWorldService service = new PocketBaseWorldService(
+            server,
+            new PluginSettingsProvider(PluginSettings.from(Map.of()))
+        );
+
+        assertTrue(service.returnPortalIsIntact(ownerId, portal));
+
+        when(world.getBlockAt(20, 65, 12).getType()).thenReturn(Material.AIR);
+        assertFalse(service.returnPortalIsIntact(ownerId, portal));
+    }
+
+    @Test
+    void reappliesSavedMobSpawningPreferenceWhenWorldLoads() {
+        UUID ownerId = UUID.randomUUID();
+        Server server = mock(Server.class);
+        World world = mock(World.class);
+        when(server.getWorld(org.mockito.ArgumentMatchers.anyString())).thenReturn(world);
+        when(world.getUID()).thenReturn(UUID.randomUUID());
+        PocketBaseWorldService service = new PocketBaseWorldService(
+            server,
+            new PluginSettingsProvider(PluginSettings.from(Map.of()))
+        );
+
+        service.loadExisting(Map.of(
+            ownerId,
+            new PocketBaseState(ownerId, 1, Optional.empty(), true)
+        ));
+
+        verify(world).setSpawnFlags(true, true);
+    }
+
+    @Test
+    void laterLevelAddsRingWithoutOverwritingExistingTerrain() {
+        UUID ownerId = UUID.randomUUID();
+        Server server = mock(Server.class);
+        World world = mock(World.class);
+        Map<BlockPosition, Block> blocks = blocks(world);
+        when(server.createWorld(any(WorldCreator.class))).thenReturn(world);
+        when(world.getUID()).thenReturn(UUID.randomUUID());
+        when(world.getName()).thenReturn("pocket");
+        PocketBaseWorldService service = new PocketBaseWorldService(
+            server,
+            new PluginSettingsProvider(PluginSettings.from(Map.of()))
+        );
+        Block existingCenter = world.getBlockAt(0, 64, 0);
+
+        service.expand(ownerId, 1, 2);
+
+        verify(blocks.get(new BlockPosition(47, 64, 47)))
+            .setType(Material.GRASS_BLOCK, false);
+        verify(existingCenter, never())
+            .setType(any(Material.class), org.mockito.ArgumentMatchers.anyBoolean());
+    }
+
+    private static Map<BlockPosition, Block> blocks(World world) {
+        Map<BlockPosition, Block> blocks = new HashMap<>();
+        when(world.getBlockAt(
+            org.mockito.ArgumentMatchers.anyInt(),
+            org.mockito.ArgumentMatchers.anyInt(),
+            org.mockito.ArgumentMatchers.anyInt()
+        )).thenAnswer(invocation -> {
+            BlockPosition position = new BlockPosition(
+                invocation.getArgument(0), invocation.getArgument(1), invocation.getArgument(2)
+            );
+            return blocks.computeIfAbsent(position, ignored -> mock(Block.class));
+        });
+        return blocks;
+    }
+}

src/test/java/games/dmg/spigotbase/PocketPortalGeometryTest.java

@@ -0,0 +1,42 @@
+package games.dmg.spigotbase;
+
+import static org.junit.jupiter.api.Assertions.assertEquals;
+import static org.junit.jupiter.api.Assertions.assertTrue;
+
+import java.util.HashSet;
+import java.util.Optional;
+import java.util.Set;
+import java.util.UUID;
+import org.junit.jupiter.api.Test;
+
+final class PocketPortalGeometryTest {
+    @Test
+    void findsStandardFrameContainingIgnitedBlock() {
+        UUID worldId = UUID.randomUUID();
+        PocketPortalLocation expected = new PocketPortalLocation(
+            worldId, "world", 10, 64, 20, PocketPortalAxis.X
+        );
+        Set<BlockPosition> frame = new HashSet<>(PocketPortalGeometry.frameBlocks(expected));
+
+        Optional<PocketPortalLocation> found = PocketPortalGeometry.findFrame(
+            new BlockPosition(10, 66, 20),
+            worldId,
+            "world",
+            frame::contains,
+            ignored -> true
+        );
+
+        assertEquals(expected, found.orElseThrow());
+    }
+
+    @Test
+    void identifiesPortalInteriorAndRequiredFrameBlocks() {
+        PocketPortalLocation portal = new PocketPortalLocation(
+            UUID.randomUUID(), "world", 0, 64, 0, PocketPortalAxis.Z
+        );
+
+        assertTrue(PocketPortalGeometry.isInterior(portal, new BlockPosition(0, 65, 1)));
+        assertTrue(PocketPortalGeometry.isFrame(portal, new BlockPosition(0, 68, 3)));
+        assertEquals(14, PocketPortalGeometry.frameBlocks(portal).size());
+    }
+}

src/test/java/games/dmg/spigotbase/SpawnableBlockPolicyTest.java

@@ -0,0 +1,48 @@
+package games.dmg.spigotbase;
+
+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.when;
+
+import org.bukkit.block.Block;
+import org.bukkit.block.BlockFace;
+import org.bukkit.block.data.type.Slab;
+import org.junit.jupiter.api.Test;
+
+final class SpawnableBlockPolicyTest {
+    @Test
+    void acceptsDarkSolidSurfaceWithTwoPassableBlocksAbove() {
+        Block surface = mock(Block.class);
+        Block above = mock(Block.class);
+        Block secondAbove = mock(Block.class);
+        Slab slab = mock(Slab.class);
+        when(slab.getType()).thenReturn(Slab.Type.TOP);
+        when(surface.getBlockData()).thenReturn(slab);
+        when(surface.getRelative(BlockFace.UP)).thenReturn(above);
+        when(above.getRelative(BlockFace.UP)).thenReturn(secondAbove);
+        when(above.isPassable()).thenReturn(true);
+        when(secondAbove.isPassable()).thenReturn(true);
+        when(above.getLightFromBlocks()).thenReturn((byte) 0);
+        when(above.getLightFromSky()).thenReturn((byte) 0);
+
+        assertTrue(SpawnableBlockPolicy.isCandidate(surface));
+    }
+
+    @Test
+    void rejectsBlockLitSurface() {
+        Block surface = mock(Block.class);
+        Block above = mock(Block.class);
+        Block secondAbove = mock(Block.class);
+        Slab slab = mock(Slab.class);
+        when(slab.getType()).thenReturn(Slab.Type.TOP);
+        when(surface.getBlockData()).thenReturn(slab);
+        when(surface.getRelative(BlockFace.UP)).thenReturn(above);
+        when(above.getRelative(BlockFace.UP)).thenReturn(secondAbove);
+        when(above.isPassable()).thenReturn(true);
+        when(secondAbove.isPassable()).thenReturn(true);
+        when(above.getLightFromBlocks()).thenReturn((byte) 1);
+
+        assertFalse(SpawnableBlockPolicy.isCandidate(surface));
+    }
+}

src/test/java/games/dmg/spigotbase/SpawnableOverlayControllerTest.java

@@ -0,0 +1,85 @@
+package games.dmg.spigotbase;
+
+import static org.mockito.ArgumentMatchers.any;
+import static org.mockito.ArgumentMatchers.eq;
+import static org.mockito.ArgumentMatchers.anyInt;
+import static org.mockito.Mockito.atLeastOnce;
+import static org.mockito.Mockito.doReturn;
+import static org.mockito.Mockito.mock;
+import static org.mockito.Mockito.verify;
+import static org.mockito.Mockito.when;
+
+import java.time.Instant;
+import java.util.Map;
+import java.util.UUID;
+import org.bukkit.Location;
+import org.bukkit.Particle;
+import org.bukkit.Server;
+import org.bukkit.World;
+import org.bukkit.block.Block;
+import org.bukkit.block.BlockFace;
+import org.bukkit.block.data.type.Slab;
+import org.bukkit.entity.Player;
+import org.junit.jupiter.api.Test;
+
+final class SpawnableOverlayControllerTest {
+    @Test
+    void ownerReceivesBoundedRedParticlesForNearbyCandidates() {
+        UUID playerId = UUID.randomUUID();
+        UUID worldId = UUID.randomUUID();
+        PlayerState state = PlayerState.newPlayer(playerId, "Builder")
+            .withAdministrativeLevels(1, 0, 0, 0, 0, false, false, false)
+            .withBase(new BaseLocation(worldId, "world", 0, 64, 0, 0, 0), Instant.EPOCH)
+            .withTotalBlocksPlaced(250)
+            .withSpawnableOverlayEnabled(true);
+
+        Block surface = mock(Block.class);
+        Block above = mock(Block.class);
+        Block secondAbove = mock(Block.class);
+        Slab slab = mock(Slab.class);
+        when(slab.getType()).thenReturn(Slab.Type.TOP);
+        when(surface.getBlockData()).thenReturn(slab);
+        when(surface.getRelative(BlockFace.UP)).thenReturn(above);
+        when(above.getRelative(BlockFace.UP)).thenReturn(secondAbove);
+        when(above.isPassable()).thenReturn(true);
+        when(secondAbove.isPassable()).thenReturn(true);
+        when(above.getLightFromBlocks()).thenReturn((byte) 0);
+        when(above.getLightFromSky()).thenReturn((byte) 0);
+
+        World world = mock(World.class);
+        when(world.getUID()).thenReturn(worldId);
+        when(world.getMinHeight()).thenReturn(-64);
+        when(world.getMaxHeight()).thenReturn(320);
+        when(world.getBlockAt(anyInt(), anyInt(), anyInt()))
+            .thenReturn(surface);
+        Player player = mock(Player.class);
+        when(player.getUniqueId()).thenReturn(playerId);
+        when(player.getName()).thenReturn("Builder");
+        when(player.getWorld()).thenReturn(world);
+        when(player.getLocation()).thenReturn(new Location(world, 0.5, 65.0, 0.5));
+        Server server = mock(Server.class);
+        doReturn(java.util.List.of(player)).when(server).getOnlinePlayers();
+        BaseStateManager stateManager = mock(BaseStateManager.class);
+        when(stateManager.player(playerId, "Builder")).thenReturn(state);
+        PluginSettingsProvider settings = new PluginSettingsProvider(
+            PluginSettings.from(Map.of())
+        );
+
+        SpawnableOverlayController controller = new SpawnableOverlayController(
+            server,
+            stateManager,
+            new BaseBoundsService(settings),
+            settings
+        );
+        controller.run();
+        controller.run();
+        controller.run();
+
+        verify(player, atLeastOnce()).spawnParticle(
+            eq(Particle.DUST),
+            any(Location.class),
+            eq(1),
+            any(Particle.DustOptions.class)
+        );
+    }
+}

src/test/java/games/dmg/spigotbase/SpawnableOverlayProgressionServiceTest.java

@@ -0,0 +1,24 @@
+package games.dmg.spigotbase;
+
+import static org.junit.jupiter.api.Assertions.assertEquals;
+import static org.junit.jupiter.api.Assertions.assertTrue;
+
+import java.util.Map;
+import java.util.UUID;
+import org.junit.jupiter.api.Test;
+
+final class SpawnableOverlayProgressionServiceTest {
+    @Test
+    void twoHundredFiftiethPlacementUnlocksOverlay() {
+        PlayerState player = PlayerState.newPlayer(UUID.randomUUID(), "Builder")
+            .withTotalBlocksPlaced(249);
+        SpawnableOverlayProgressionService service = new SpawnableOverlayProgressionService(
+            new PluginSettingsProvider(PluginSettings.from(Map.of()))
+        );
+
+        SpawnableOverlayProgressionUpdate update = service.recordPlacement(player);
+
+        assertEquals(250, update.player().totalBlocksPlaced());
+        assertTrue(update.unlocked());
+    }
+}

src/test/java/games/dmg/spigotbase/TeleportPolicyTest.java

@@ -22,6 +22,17 @@ final class TeleportPolicyTest {
         assertEquals(Duration.ZERO, policy.warmup(player.withTeleportLevels(3, 0)));
     }
 
+    @Test
+    void visitorWarmupHasOneSecondMinimum() {
+        PlayerState player = baseThreePlayer();
+
+        assertEquals(Duration.ofSeconds(30), policy.visitorWarmup(player));
+        assertEquals(
+            Duration.ofSeconds(1),
+            policy.visitorWarmup(player.withTeleportLevels(3, 0))
+        );
+    }
+
     @Test
     void cooldownLevelsUseApprovedDurations() {
         PlayerState player = baseThreePlayer();

src/test/java/games/dmg/spigotbase/YamlBaseStateRepositoryTest.java

@@ -28,7 +28,10 @@ final class YamlBaseStateRepositoryTest {
             true, true, false, true,
             Optional.of(Instant.ofEpochMilli(1_750_000_000_000L)),
             Optional.of(Instant.ofEpochMilli(1_750_000_100_000L)),
-            Map.of(ownerId, Instant.ofEpochMilli(1_750_001_000_000L))
+            Map.of(ownerId, Instant.ofEpochMilli(1_750_001_000_000L)),
+            true,
+            2_500,
+            true
         );
         PersistentState expected = new PersistentState(Map.of(playerId, player));
         YamlBaseStateRepository repository =
@@ -39,6 +42,44 @@ final class YamlBaseStateRepositoryTest {
         assertEquals(expected, repository.load());
     }
 
+    @Test
+    void olderStateUsesKnownInBasePlacementsAsTotalPlacementMinimum() throws Exception {
+        UUID playerId = UUID.randomUUID();
+        Path stateFile = temporaryDirectory.resolve("state.yml");
+        Files.writeString(stateFile, """
+            players:
+              %s:
+                name: Alex
+                blocks-placed-in-base: 225
+            """.formatted(playerId));
+
+        PlayerState player = new YamlBaseStateRepository(stateFile)
+            .load()
+            .players()
+            .get(playerId);
+
+        assertEquals(225, player.totalBlocksPlaced());
+        assertFalse(player.spawnableOverlayEnabled());
+    }
+
+    @Test
+    void olderStateWithoutBorderPreferenceDefaultsToDisabled() throws Exception {
+        UUID playerId = UUID.randomUUID();
+        Path stateFile = temporaryDirectory.resolve("state.yml");
+        Files.writeString(stateFile, """
+            players:
+              %s:
+                name: Alex
+            """.formatted(playerId));
+
+        PlayerState player = new YamlBaseStateRepository(stateFile)
+            .load()
+            .players()
+            .get(playerId);
+
+        assertFalse(player.borderEnabled());
+    }
+
     @Test
     void invalidRecordsCannotGrantProgression() throws Exception {
         UUID playerId = UUID.randomUUID();

src/test/java/games/dmg/spigotbase/YamlPocketBaseRepositoryTest.java

@@ -0,0 +1,55 @@
+package games.dmg.spigotbase;
+
+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.nio.file.Files;
+import java.nio.file.Path;
+import java.util.Map;
+import java.util.Optional;
+import java.util.UUID;
+import org.junit.jupiter.api.Test;
+import org.junit.jupiter.api.io.TempDir;
+
+final class YamlPocketBaseRepositoryTest {
+    @TempDir
+    Path temporaryDirectory;
+
+    @Test
+    void roundTripsLevelsAndActiveEntrances() throws Exception {
+        UUID ownerId = UUID.randomUUID();
+        UUID worldId = UUID.randomUUID();
+        PocketBaseState expected = new PocketBaseState(
+            ownerId,
+            7,
+            Optional.of(new PocketPortalLocation(
+                worldId, "world", 10, 65, -4, PocketPortalAxis.X
+            )),
+            Optional.of(new PocketPortalLocation(
+                worldId, "pocket", 20, 65, 12, PocketPortalAxis.Z
+            )),
+            true
+        );
+        YamlPocketBaseRepository repository = new YamlPocketBaseRepository(
+            temporaryDirectory.resolve("pocket-bases.yml")
+        );
+
+        repository.save(Map.of(ownerId, expected));
+
+        assertEquals(expected, repository.load().get(ownerId));
+    }
+
+    @Test
+    void existingRecordWithoutMobPreferenceDefaultsToDisabled() throws Exception {
+        UUID ownerId = UUID.randomUUID();
+        Path stateFile = temporaryDirectory.resolve("pocket-bases.yml");
+        Files.writeString(stateFile, "owners:\n  " + ownerId + ":\n    level: 1\n");
+        YamlPocketBaseRepository repository = new YamlPocketBaseRepository(stateFile);
+
+        PocketBaseState loaded = repository.load().get(ownerId);
+
+        assertFalse(loaded.mobSpawningEnabled());
+        assertTrue(loaded.returnPortal().isEmpty());
+    }
+}