Added live instability for block generation

build.gradle

@@ -17,7 +17,7 @@ tasks.named('wrapper', Wrapper).configure {
 version = mod_version
 group = mod_group_id
 
-List<String> archivedGameTestSuites = ['linking', 'environment', 'writing', 'grammar', 'generation', 'desk', 'binder', 'mixer', 'recipe']
+List<String> archivedGameTestSuites = ['linking', 'environment', 'writing', 'grammar', 'generation', 'desk', 'binder', 'mixer', 'recipe', 'instability']
 List<String> selectedArchivedGameTestSuites = providers.gradleProperty('withArchivedGameTests')
         .map { it.toBoolean() }.orElse(false).get() ? archivedGameTestSuites
         : providers.gradleProperty('archivedGameTestSuites').orElse('').get()

docs/GAMETESTS.md

@@ -18,12 +18,13 @@ core tests when investigating an issue:
 ./gradlew runGameTestServer -ParchivedGameTestSuites=desk
 ./gradlew runGameTestServer -ParchivedGameTestSuites=grammar,binder
 ./gradlew runGameTestServer -ParchivedGameTestSuites=generation
+./gradlew runGameTestServer -ParchivedGameTestSuites=instability
 ```
 
 Available suite names are `linking`, `environment`, `writing`, `grammar`,
-`generation`, `desk`, `binder`, `mixer`, and `recipe`. The `generation` archive
+`generation`, `desk`, `binder`, `mixer`, `recipe`, and `instability`. The `generation` archive
 keeps the detailed feature, structure, ore, crystal, and fissure regressions
-out of the default smoke run. Three checks formerly registered twice in the
+out of the default smoke run. The `instability` archive adds multi-player loaded-chunk selection, policy gates, and protected-block checks without rerunning the default scoring and migration tests. Three checks formerly registered twice in the
 core and their archives now run only through the core wrapper. Run all
 Rivencraft tests before a
 release or after broad cross-system changes:

docs/INSTABILITY_RUNTIME.md

@@ -4,12 +4,21 @@ Each new Age stores an `InstabilityPlan` beside its frozen `Instability` score.
 
 The saved provider IDs are independent of installed handlers. A missing optional handler leaves its ID and level intact and is skipped at runtime. A syntactically invalid saved ID or unsupported plan version fails loading explicitly; an unknown but valid ID is preserved and logged once when encountered. Disabling instability or world mutation never rewrites a saved score or provider plan. Saves from #64 with a frozen score but no provider plan are selected once from that score and Age seed, then marked dirty for persistence. Older pre-score Ages remain neutral and inert.
 
+From 0.5.8.11, [live block profiling](LIVE_BLOCK_INSTABILITY.md) adds a separate
+effective score and provider plan once 400 Age and Overworld chunks have been
+sampled. The authored score/plan described above remain saved as the base;
+the effective provider selection can change as block abundance is observed.
+
 The server scheduler runs only for loaded `rivencraft:age/*` levels with a player present and an Age definition. It uses only chunks already loaded near those players, never requests a chunk, and rotates among eligible Ages when the per-tick cap is reached. Configuration bounds the cooldown (minimum 20 ticks), active Ages, handlers and actions per Age, effective provider level, and examined loaded chunks. A handler must claim a shared action permit before each effect. A throwing handler is logged and quarantined temporarily without stopping the server. World-mutating handlers are enabled by default to match Legacy; the setting can still disable them. These limits are guards for upcoming providers, not proof that an arbitrary third-party handler cannot misuse world APIs.
 
 Issue #67 registers the non-world-mutating potion handlers; see [status-effect policy](INSTABILITY_STATUS_EFFECTS.md). Issue #68 adds configurable [colored decay](INSTABILITY_DECAY.md), enabled by default for newly generated configs. Issue #69 adds lightning and explosions; issue #70 adds [meteor, scorching, and erosion](INSTABILITY_ENVIRONMENTAL.md). The runtime rejects Overworld and preview dimension IDs; its player requirement excludes unattended snapshot chunk loaders. GameTests cover deterministic selection, save round-trips, score-only migration, unknown IDs, scope checks, fair admission, and action caps.
 
 Issue #72 adds [server config, per-Age controls, diagnostics, and book feedback](INSTABILITY_DIAGNOSTICS.md). Its operator controls never rewrite a frozen score or provider plan.
 
+The Milestone 6 [regression and migration record](MILESTONE_6_REGRESSION.md)
+maps the automated acceptance checks and lists the in-game restart, optional-mod,
+and hazard-visual scenarios still requiring verification.
+
 # Lightning and explosions (#69)
 
 The `lightning` and `explosions` cards now run only in loaded Rivencraft Ages with players. Legacy rolled once per chunk per tick: explosions at 1/1000 and lightning at 1/5000 during thunder or 1/100000 otherwise. Each selected hazard card gets an independent roll every scheduler pass, rather than waiting for the rotating two-provider sample. The roll uses up to 81 already-loaded chunks near Age players and the exact probability of at least one Legacy opportunity over that many chunk-ticks. It permits at most one event per hazard type per pass. A per-Age saved sequence and last-event time prevent the same roll/event from replaying after a restart. Lightning also skips an existing bolt at the target.

docs/INSTABILITY_SCORE.md

@@ -6,6 +6,10 @@ The baseline is explicitly zero for page-free and Link-Panel-only random Ages, a
 
 The score is calculated after the Age plan and effective traits are chosen, then saved with the Age identity before its dimension is generated. The same UUID returns the existing definition, including the same score, on repeated use. Spawn updates preserve it. Reload only deserializes the frozen breakdown; it never reruns the current grammar or catalog. An older Age definition without `Instability` is migrated to a persisted version-1 neutral score of zero, rather than retroactively scoring its writing. A future scoring-rule change must introduce an explicit new schema/migration policy, not silently reinterpret existing Ages. Issue #66 added the frozen provider selection; issues #67–#70 added the current handlers. See the [runtime policy](INSTABILITY_RUNTIME.md).
 
+This is now the **authored base** score. [Live block profiling](LIVE_BLOCK_INSTABILITY.md)
+keeps its sample counts separately and may add a changing effective block score
+without rewriting the authored breakdown or its saved base provider plan.
+
 Unknown or unsupported pages remain invalid for *new* Ages. Their absence from a later registry does not change an already saved score. Focused GameTests cover stable/defective writing, random baseline and bright lighting, repeated identity, save round-trip, and missing-symbol/old-save behavior.
 
 `/rivencraft age instability` inspects the Age containing the command source; an optional dimension ID inspects an unloaded or different registered Age. It reports immutable base score, stability bonus, runtime penalty, and effective score. The pinned Legacy tree defines player-death and player-presence bonus classes but does not register them as default providers, so Rivencraft leaves player-driven modifiers disabled: bonus and penalty are zero and effective equals base. There is therefore no mutable bonus save to migrate in this release. No death, PvP event, player identity, or dimension transition can transfer stability between Ages. Any future opt-in mechanic must persist separately from `Instability`, define caps and reset behavior, and must not rewrite the generation plan or frozen provider plan.

docs/LEGACY_INSTABILITY_AUDIT.md

@@ -4,7 +4,7 @@ This is the behavior contract used to implement Milestone 6. It is pinned to [My
 
 ## Score, grammar, and selection in Legacy
 
-Legacy's [`AgeController`](https://github.com/Mystcraft/Mystcraft-Legacy/blob/9bc8ddc061845df0cd5ea47f4fdef773cff786ae/src/main/java/com/xcompwiz/mystcraft/world/AgeController.java) calculates `debug + symbol + block + book/base + bonus`, then applies difficulty 0/1/2/3 multipliers of 0.25/0.5/1/1.75. Global instability is enabled by default; an Age also has its own enable flag. The unmodified score is not simply “number of bad pages.” Block profiling may delay a usable score: `blockinstability` is null until **more than** 400 Age chunks are profiled, and `getInstabilityScore()` returns zero until then. It is recalculated after additional profiling. [`ChunkProfiler`](https://github.com/Mystcraft/Mystcraft-Legacy/blob/9bc8ddc061845df0cd5ea47f4fdef773cff786ae/src/main/java/com/xcompwiz/mystcraft/world/profiling/ChunkProfiler.java) compares watched block abundance with a baseline, subtracting only positive excess above each baseline. The baseline is profiled or read from balance config; [`InstabilityDataCalculator`](https://github.com/Mystcraft/Mystcraft-Legacy/blob/9bc8ddc061845df0cd5ea47f4fdef773cff786ae/src/main/java/com/xcompwiz/mystcraft/world/profiling/InstabilityDataCalculator.java) sets its default tolerance to 1.05, and default `useconfigs=false`. We should not copy its 400-chunk profiling delay or dynamic block scan into 1.21.1 without a separate performance case.
+Legacy's [`AgeController`](https://github.com/Mystcraft/Mystcraft-Legacy/blob/9bc8ddc061845df0cd5ea47f4fdef773cff786ae/src/main/java/com/xcompwiz/mystcraft/world/AgeController.java) calculates `debug + symbol + block + book/base + bonus`, then applies difficulty 0/1/2/3 multipliers of 0.25/0.5/1/1.75. Global instability is enabled by default; an Age also has its own enable flag. The unmodified score is not simply “number of bad pages.” Block profiling may delay a usable score: `blockinstability` is null until **more than** 400 Age chunks are profiled, and `getInstabilityScore()` returns zero until then. It is recalculated after additional profiling. [`ChunkProfiler`](https://github.com/Mystcraft/Mystcraft-Legacy/blob/9bc8ddc061845df0cd5ea47f4fdef773cff786ae/src/main/java/com/xcompwiz/mystcraft/world/profiling/ChunkProfiler.java) compares watched block abundance with a baseline, subtracting only positive excess above each baseline. The baseline is profiled or read from balance config; [`InstabilityDataCalculator`](https://github.com/Mystcraft/Mystcraft-Legacy/blob/9bc8ddc061845df0cd5ea47f4fdef773cff786ae/src/main/java/com/xcompwiz/mystcraft/world/profiling/InstabilityDataCalculator.java) sets its default tolerance to 1.05, and default `useconfigs=false`. Rivencraft's later [bounded implementation](LIVE_BLOCK_INSTABILITY.md) retains the threshold and tolerance, but not Legacy's spatial accessibility formula or unbounded profiling.
 
 | Input | Verified Legacy behavior | Rivencraft M6 interpretation |
 | --- | --- | --- |
@@ -15,7 +15,7 @@ Legacy's [`AgeController`](https://github.com/Mystcraft/Mystcraft-Legacy/blob/9b
 | Unsupported/unmatched page | Legacy logs unmatched symbols during reconstruction and skips their logic; its `AgeData.getBaseInstability()` still has a TODO for calculating instability from pages. This is not a sound compatibility contract. | Remains fatal for *new* books until semantic and runtime support exists; never silently erase the page or pretend its effect applied. Existing saved books retain their IDs. |
 | Other penalties/bonuses | `AgeController.addInstability(int)` is available to symbol logic. The base/book score is persisted as a `short`; Legacy's [`InstabilityBonusManager`](https://github.com/Mystcraft/Mystcraft-Legacy/blob/9bc8ddc061845df0cd5ea47f4fdef773cff786ae/src/main/java/com/xcompwiz/mystcraft/instability/bonus/InstabilityBonusManager.java) also has dynamic player death/behavior components. | Persist a versioned score breakdown for Age writing and environmental contributions. Do not infer death/troll mechanics from the mere existence of Legacy classes. |
 
-The complete Legacy `instabilityModifier` audit found direct feature-page costs only for Mineshafts, Nether Fortresses, Strongholds, and Villages. Their first three occurrences cost zero; the fourth and every later occurrence adds 100. Every other Legacy feature class inherited `SymbolBase`'s zero modifier. Rivencraft applies that exact rule to the four matching pages. By project balance decision, Bastions, Trial Chambers, Ancient Cities, Shipwrecks, Ocean Ruins, Pillager Outposts, Ruined Portals, Nether Fossils, Buried Treasure, and Trail Ruins use the same repeat rule. Matching Legacy features such as Caves, Crystal Formations, Dense Ores, Dungeons, Floating Islands, Huge Trees, Deep/Surface Lakes, Obelisks, Ravines, Skylands, Spheres, Spikes, Star Fissures, and Tendrils have no direct page cost. Legacy could still derive instability later from excess profiled blocks, especially ores, but that separate 400-chunk profiling system is intentionally not ported. Other modern-only Rivencraft features remain neutral.
+The complete Legacy `instabilityModifier` audit found direct feature-page costs only for Mineshafts, Nether Fortresses, Strongholds, and Villages. Their first three occurrences cost zero; the fourth and every later occurrence adds 100. Every other Legacy feature class inherited `SymbolBase`'s zero modifier. Rivencraft applies that exact rule to the four matching pages. By project balance decision, Bastions, Trial Chambers, Ancient Cities, Shipwrecks, Ocean Ruins, Pillager Outposts, Ruined Portals, Nether Fossils, Buried Treasure, and Trail Ruins use the same repeat rule. Matching Legacy features such as Caves, Crystal Formations, Dense Ores, Dungeons, Floating Islands, Huge Trees, Deep/Surface Lakes, Obelisks, Ravines, Skylands, Spheres, Spikes, Star Fissures, and Tendrils have no direct page cost. Legacy could still derive instability later from excess profiled blocks, especially ores. From 0.5.8.11, Rivencraft has a [bounded live block-profile adaptation](LIVE_BLOCK_INSTABILITY.md) using the 400-chunk threshold, including diamond blocks as a deliberate non-Legacy extension. Other modern-only Rivencraft features remain neutral unless they increase watched-block abundance.
 
 Bright Lighting adds 500 for every authored occurrence. A generated Bright Lighting controller also adds 500. This is independent of the 500-point extra-controller cost, so two authored Bright Lighting pages produce 1,500 total: 500 for each symbol and 500 for the repeated controller.
 

docs/LIVE_BLOCK_INSTABILITY.md

@@ -0,0 +1,73 @@
+# Live block-instability profiling (0.5.8.11)
+
+Mystcraft Legacy measures the abundance of watched blocks in generated chunks,
+compares that abundance with a baseline, and adds only positive excess to the
+Age's instability. Its `InstabilityBlockManager` and `ChunkProfiler` are
+available in the user's local 0.13.7.06 archive. Legacy's Age-side threshold
+is more than 400 profiled chunks; its default tolerance is 1.05. The Legacy watched
+blocks include coal, lapis, iron, emerald, redstone, gold and diamond ores,
+quartz ore, glowstone, and crystal blocks. Diamond **blocks** are not on that
+default list, but are included here at the player's request.
+
+Rivencraft samples up to 1,024 distinct, newly generated chunks per dimension,
+at most four per server tick. It never generates a chunk merely to profile it.
+The Overworld is sampled as the baseline; an Age needs 401 samples and the
+baseline needs 500 before the live block component contributes points. Counts and sampled chunk
+positions persist per dimension, preventing reloads from double-counting.
+For each watched block, Rivencraft compares average blocks per sampled chunk
+and charges `max(0, Age average − 1.05 × Overworld average) × weight`, rounded
+to the nearest point. The block component is capped at 100,000 points.
+
+Legacy weights are used for its watched blocks: coal/lapis 5, iron 60, emerald
+200, redstone 250, gold 750, diamond 4,000, quartz/crystal 20, and glowstone
+50. Deepslate variants inherit their ore's weight. Modern/high-value extensions
+include diamond, emerald, gold, iron, raw gold, raw iron and netherite storage
+blocks, plus ancient debris. Netherite blocks cost 8,000 per excess block per
+sampled chunk; ancient debris costs 4,000. Modded blocks are not automatically
+classified as valuable; this avoids charging unknown decorative materials.
+
+The authored score and provider plan remain saved as the Age's immutable base.
+Only Ages created with instability schema v2 participate; existing v1 Ages
+retain their previously frozen scores/plans, including neutral pre-scoring
+Ages. This avoids silently rescoring existing worlds.
+The live block component creates a deterministic **effective** score and
+provider plan from that base plus the persisted profile; new cards can become
+active as sampled abundance rises. The command `/rivencraft age instability`
+shows both the saved base and the currently profiled block component. An
+unloaded Age has no active profile view until its dimension is loaded again.
+Turning an effect off does not delete counts or reroll the same effective plan.
+
+This is not byte-for-byte Legacy profiling. Legacy has a spatial accessibility
+map and two factors per block, actively builds a dummy-world baseline, and can
+recompute after subsequent chunk profiling. Rivencraft uses a simpler
+per-chunk abundance metric, a real-world Overworld baseline, a sample/work cap,
+and a saved authored base so modern servers remain bounded and restart-safe.
+The greater-than-400-chunk activation delay is retained. Because only newly
+generated chunks are sampled, old already-explored worlds may need substantial
+new exploration before their Overworld baseline is ready. A mod that mutates
+blocks after the chunk-load event may not be reflected in the first sample.
+
+## Manual check handed to the player
+
+The first focused GameTest run after adding the chunk-load listener stalled in
+its initial 50-test batch and was stopped. It is **not** a passing test result.
+Do not retry that stalled scenario automatically. In a disposable world:
+
+1. Create one Age with an authored Diamond Block + Rocks (or Floating Islands)
+   combination and a comparison Age using Stone for the same feature. Explore
+   enough distinct chunks in each Age for `/rivencraft age instability` to show
+   a profiled-block contribution. Explore the Overworld too if its baseline has
+   not reached 400 chunks. The diamond Age should score higher and can gain
+   provider cards; the stone Age should not get a diamond-block contribution.
+2. Leave and restart the world. Re-enter both Ages and compare their scores and
+   provider IDs/levels. Reloading old chunks must not increase the sample
+   count or score by itself. Generating more diamond-rich chunks may change the
+   effective score and provider set; disabling instability must suppress their
+   effects without erasing the profile.
+3. Check a naturally generated diamond-ore Age without authored diamond-block
+   features. If its ore abundance is near the Overworld baseline, it should
+   receive little or no ore contribution. Check that profiling does not make
+   chunk loading noticeably stall, and report any exception or server hang.
+
+Do not use a valued save for this check. The game jar builds, but live chunk
+profiling still needs this player-run validation before release.

docs/MILESTONE_6_REGRESSION.md

@@ -0,0 +1,95 @@
+# Milestone 6 instability regression and migration check (#73)
+
+This is the release-slice acceptance record for instability, not a promise of
+general old-save compatibility. The latter remains issue #60. Run the focused
+archive with `./gradlew build runGameTestServer -ParchivedGameTestSuites=instability`;
+it includes the default smoke suite.
+For 0.5.8.10 on 2026-10-10, that dedicated GameTest server passed all 55 required tests
+with no optional content/client integrations installed (the required Dynamic
+Dimensions and Bad Packets dependencies were present). The full archive was not run;
+it has a previously documented storage stall, so do not count it as passing.
+The 0.5.8.11 run with live block profiling stalled in its initial batch and
+was stopped; it is **not** a passing result. The live profiling scenario is
+handed to the player in [the block-profile checklist](LIVE_BLOCK_INSTABILITY.md).
+
+## Automated coverage
+
+| Requirement | Existing default test or focused archive |
+| --- | --- |
+| Stable writing, defective writing, score explanations, repeated use of the same book | `AgePersistenceGameTests.instabilitySeparatesStableAndDefectiveWriting` |
+| Frozen score, age-scoped writing cost, random baseline | `AgePersistenceGameTests.randomBaselineAndBrightBalanceAreFrozen`, `auditedSymbolCostsAreCountedAndAgeScoped` |
+| Complete Age definition, score and provider-plan save/load | `AgePersistenceGameTests.authoredPlanRetainsResolvedMeaningAndAgeIdentity`; `AgeInstabilityRuntimeGameTests.selectionIsDeterministicAndFrozen` |
+| Old pre-scoring Ages, score-only saves, removed symbols, unavailable handlers | `AgePersistenceGameTests.missingRegistryEntryDoesNotReinterpretAnOldAge`, `instabilitySeparatesStableAndDefectiveWriting`; `AgeInstabilityRuntimeGameTests.savedPlanSurvivesAgeUpdatesAndMissingHandlers` |
+| Per-Age controls and changed config without score/plan reroll | `AgeInstabilityRuntimeGameTests.perAgeControlsPersistWithoutChangingScoresOrOtherAges`; `Milestone6RegressionGameTests.disablingEffectsCannotRerollFrozenPlan` |
+| Hazard cooldown and attempt sequence across saved-state reload | `AgeInstabilityRuntimeGameTests.hazardCooldownAndAttemptSequenceSurviveReload` |
+| Active-Age rotation, action/tick budget | `AgeInstabilityRuntimeGameTests.ageScopeRotationAndActionBudgetAreBounded` |
+| Multiplayer loaded-chunk-only candidate selection, deduplication and cap | `Milestone6RegressionGameTests.multiplayerCandidatesStayLoadedDeduplicatedAndCapped` |
+| Decay loaded-chunk target and spawn protection | `AgeDecayGameTests.targetMustRemainInChosenLoadedChunk`, `savedSpawnAndPlatformAreProtected` |
+| Explosion policy gates and protected blocks | `Milestone6RegressionGameTests.disabledGriefAndProtectedBlocksStayUntouched` |
+| No Overworld status or decay provider | `AgeStatusEffectGameTests.overworldCannotRunAnAgeStatusProvider`; `AgeDecayGameTests.overworldCannotRunDecayProvider` |
+
+These tests exercise saved-data serialization and deterministic policies. They
+do **not** simulate a complete process restart, an actual multiplayer server,
+optional-mod installation, or real terrain and hazard visuals. The three new
+checks live only in the `instability` archive to avoid duplicating default tests.
+
+## Migration outcome and known gaps
+
+- Pre-scoring Milestone 5 Ages load with a neutral score and no effects; they
+  are not retroactively rescored under current writing rules.
+- Score-only Ages receive a deterministic provider plan once from their saved
+  score and Age seed. An already-saved score and plan retain their meaning when
+  pages, handlers, or runtime config change. Unknown but syntactically valid
+  provider IDs are preserved and skipped if their handler is unavailable.
+- Missing symbol definitions do not reinterpret a frozen instability score.
+  That check is narrower than arbitrary missing biome, block, or worldgen
+  registry entries: loading a world with removed data packs is not guaranteed.
+  Broad save compatibility and migration remain tracked in #60.
+- In-process roundtrips cannot prove that Age dimensions reload correctly
+  after a full stop/start. Check that in a real client/server world. Do not add
+  another GameTest for it if it hits the documented storage stall; hand the
+  exact scenario to the player instead.
+- The dedicated GameTest run establishes classloading with no optional runtime
+  flags. It does not establish classloading with every optional integration
+  installed, nor the reverse of removing one from an existing save.
+
+## Manual in-game matrix
+
+Use a fresh test world, then keep one save for the restart and data-pack checks.
+Record the seed, mod list, age name, and `/rivencraft age instability` output
+before and after each change. Do not deliberately remove a required registry
+entry from a valued world; copy the test save first.
+
+1. Bind a low-instability book and a deliberately unstable book. Reuse each
+   book and verify the Age name, dimension ID, score, selected providers and
+   provider levels remain unchanged. Exit the Ages, stop Minecraft completely,
+   restart and re-enter; compare the same diagnostic values.
+2. With two survival players in one unstable Age and a third player in the
+   Overworld, verify effects stay in the Age, follow the Age players, and do
+   not appear in the Overworld. Move both Age players away, let old chunks
+   unload, and confirm hazards do not keep remote chunks loaded or operate
+   there. Confirm controls on one Age do not alter a second Age.
+3. Disable global instability, then world mutation, then one provider. Verify
+   the suppressed effect stops and the frozen score/plan do not change after
+   re-enabling or restarting. With block destruction disabled, trigger an
+   explosion in an expendable Age; check that arrival platforms, portals,
+   block entities and protected blocks survive. Check lightning, explosion,
+   decay, status-effect, burning, meteor and erosion visuals where selected.
+4. With Biomes O' Plenty or another TerraBlender biome mod, confirm recognized
+   biome pages still author an Age and the instability diagnostics remain
+   stable after restart. Repeat with Serene Seasons installed, then absent in
+   a disposable copy; confirm its Age season behavior and that Rivencraft
+   itself still loads. JEI should display the relevant pages and recipes when
+   installed, while the mod works without it.
+5. Check the book preview separately with its fallback animation, Ponder/Create,
+   and Immersive Portals when available. Opening a book should not change
+   player location, instability diagnostics, or ambient audio in the actual
+   Age. Do not install both season mods together for this matrix.
+6. On a copied save, remove or alter a **nonessential** data pack providing
+   a writing symbol or optional handler, then reload. Existing saved scores
+   and provider plans must not reroll. If a referenced worldgen registry entry
+   prevents load, record it against issue #60 rather than treating #73's
+   frozen-instability guarantee as general missing-registry support.
+
+The matrix is guidance for a player-run pass; none of these six scenarios is
+claimed as completed by the automated result above.

gradle.properties

@@ -36,7 +36,7 @@ mod_name=Rivencraft
 # The license of the mod. Review your options at https://choosealicense.com/. All Rights Reserved is the default.
 mod_license=LGPL-3.0-or-later
 # The mod version. Rivencraft uses the x.y.z.b policy documented in README.md.
-mod_version=0.5.8.9
+mod_version=0.5.8.11
 immersive_portals_version=6.0.7
 terrablender_version=4.1.0.8
 serene_seasons_version_id=B6nTjh4b

src/main/java/net/dnorberg/rivencraft/Rivencraft.java

@@ -62,6 +62,9 @@ public final class Rivencraft {
         NeoForge.EVENT_BUS.addListener(BookStandConversionHandler::onRightClickBlock);
         NeoForge.EVENT_BUS.addListener(AgeWeatherService::onLevelTickPost);
         NeoForge.EVENT_BUS.addListener(AgeInstabilityRuntime::onLevelTickPost);
+        NeoForge.EVENT_BUS.addListener(net.dnorberg.rivencraft.book.AgeBlockInstability::onChunkLoad);
+        NeoForge.EVENT_BUS.addListener(net.dnorberg.rivencraft.book.AgeBlockInstability::onServerTickPost);
+        NeoForge.EVENT_BUS.addListener(net.dnorberg.rivencraft.book.AgeBlockInstability::onServerStopping);
         NeoForge.EVENT_BUS.addListener(AgeEnvironmentalProviders::onLevelTickPost);
         NeoForge.EVENT_BUS.addListener(AgeEnvironmentalProviders::onLevelUnload);
         NeoForge.EVENT_BUS.addListener(AgeStatusEffectProviders::onServerTickPost);

src/main/java/net/dnorberg/rivencraft/book/AgeBlockInstability.java

@@ -0,0 +1,133 @@
+package net.dnorberg.rivencraft.book;
+
+import java.util.ArrayDeque;
+import java.util.HashMap;
+import java.util.Map;
+import net.minecraft.resources.ResourceLocation;
+import net.minecraft.server.MinecraftServer;
+import net.minecraft.server.level.ServerLevel;
+import net.minecraft.world.level.chunk.LevelChunk;
+import net.neoforged.neoforge.event.level.ChunkEvent;
+import net.neoforged.neoforge.event.server.ServerStoppingEvent;
+import net.neoforged.neoforge.event.tick.ServerTickEvent;
+
+/** Legacy-style excess-block profiling; no chunks are generated or force-loaded for sampling. */
+public final class AgeBlockInstability {
+    // Legacy's watched blocks and factor-1 values; modern ore variants share their parent weight.
+    // Storage blocks are deliberate extensions, including the requested diamond-block case.
+    private static final Map<ResourceLocation, Integer> WEIGHTS = weights();
+    private static final int MAX_PENDING = 2048;
+    private static final int SAMPLES_PER_TICK = 4;
+    private static final Map<MinecraftServer, ArrayDeque<Pending>> PENDING = new java.util.WeakHashMap<>();
+
+    private AgeBlockInstability() {}
+
+    static int weight(ResourceLocation id) { return WEIGHTS.getOrDefault(id, 0); }
+
+    public static void onChunkLoad(ChunkEvent.Load event) {
+        if (!event.isNewChunk() || !(event.getLevel() instanceof ServerLevel level)
+                || !(event.getChunk() instanceof LevelChunk chunk)) return;
+        boolean overworld = level.dimension() == net.minecraft.world.level.Level.OVERWORLD;
+        if (!overworld && !AgeInstabilityRuntime.isAgeDimension(level.dimension().location())) return;
+        // Chunk-load callbacks can occur while chunk storage is updating. Defer saved-data
+        // access to a bounded server-tick lane to avoid reentering that storage path.
+        synchronized (PENDING) {
+            var queue = PENDING.computeIfAbsent(level.getServer(), ignored -> new ArrayDeque<>());
+            if (queue.size() < MAX_PENDING) queue.addLast(new Pending(level, chunk));
+        }
+    }
+
+    public static void onServerTickPost(ServerTickEvent.Post event) {
+        for (int index = 0; index < SAMPLES_PER_TICK; index++) {
+            Pending pending;
+            synchronized (PENDING) {
+                var queue = PENDING.get(event.getServer());
+                pending = queue == null ? null : queue.pollFirst();
+            }
+            if (pending == null) return;
+            var pos = pending.chunk().getPos();
+            if (pending.level().getChunkSource().hasChunk(pos.x, pos.z))
+                AgeBlockProfileSavedData.get(pending.level()).sample(pending.chunk());
+        }
+    }
+
+    public static void onServerStopping(ServerStoppingEvent event) {
+        synchronized (PENDING) { PENDING.remove(event.getServer()); }
+    }
+
+    /** Zero until the Age exceeds 400 samples and the baseline reaches 500. */
+    static int score(AgeBlockProfileSavedData age, AgeBlockProfileSavedData baseline) {
+        return score(age.totals(), age.count(), baseline.totals(), baseline.count());
+    }
+
+    static int score(Map<ResourceLocation, Long> age, int ageChunks,
+                     Map<ResourceLocation, Long> baseline, int baselineChunks) {
+        if (ageChunks < AgeBlockProfileSavedData.MIN_AGE_SAMPLES
+                || baselineChunks < AgeBlockProfileSavedData.MIN_BASELINE_SAMPLES) return 0;
+        double result = 0;
+        for (var entry : WEIGHTS.entrySet()) {
+            double excess = age.getOrDefault(entry.getKey(), 0L) / (double) ageChunks
+                    - 1.05 * baseline.getOrDefault(entry.getKey(), 0L) / (double) baselineChunks;
+            if (excess > 0) result += excess * entry.getValue();
+        }
+        return (int) Math.min(100_000, Math.round(result));
+    }
+
+    public static int score(ServerLevel level, AgeDefinition age) {
+        if (age.instability().version() < 2
+                || !AgeInstabilityRuntime.isAgeDimension(level.dimension().location())
+                || !age.dimensionId().equals(level.dimension().location())) return 0;
+        return score(AgeBlockProfileSavedData.get(level),
+                AgeBlockProfileSavedData.get(level.getServer().overworld()));
+    }
+
+    public static int sampledChunks(ServerLevel level) {
+        return AgeBlockProfileSavedData.get(level).count();
+    }
+
+    public static int effectiveScore(ServerLevel level, AgeDefinition age) {
+        return (int) Math.min(Integer.MAX_VALUE, (long) age.instability().score() + score(level, age));
+    }
+
+    public static AgeInstabilityPlan effectivePlan(ServerLevel level, AgeDefinition age) {
+        int blockScore = score(level, age);
+        if (blockScore == 0) return age.instabilityPlan();
+        int combined = effectiveScore(level, age);
+        AgeInstability effective = new AgeInstability(AgeInstability.CURRENT_VERSION, combined,
+                java.util.List.of(new AgeInstability.Contribution("effective_block_profile", -1, combined,
+                        "Saved writing score plus sampled excess blocks")));
+        var selected = AgeInstabilityPlan.select(effective, age.seed());
+        Map<ResourceLocation, Integer> levels = new java.util.LinkedHashMap<>();
+        age.instabilityPlan().providers().forEach(provider -> levels.put(provider.id(), provider.level()));
+        selected.providers().forEach(provider -> levels.merge(provider.id(), provider.level(), Math::max));
+        return new AgeInstabilityPlan(AgeInstabilityPlan.CURRENT_VERSION,
+                levels.entrySet().stream().map(entry ->
+                        new AgeInstabilityPlan.ProviderLevel(entry.getKey(), entry.getValue())).toList());
+    }
+
+    private static Map<ResourceLocation, Integer> weights() {
+        Map<ResourceLocation, Integer> values = new HashMap<>();
+        add(values, 5, "coal_ore", "deepslate_coal_ore", "lapis_ore", "deepslate_lapis_ore");
+        add(values, 60, "iron_ore", "deepslate_iron_ore");
+        add(values, 200, "emerald_ore", "deepslate_emerald_ore");
+        add(values, 250, "redstone_ore", "deepslate_redstone_ore");
+        add(values, 750, "gold_ore", "deepslate_gold_ore");
+        add(values, 4000, "diamond_ore", "deepslate_diamond_ore", "diamond_block");
+        add(values, 20, "nether_quartz_ore");
+        add(values, 50, "glowstone");
+        values.put(ResourceLocation.parse("rivencraft:crystal_block"), 20);
+        // Valuable blocks introduced after Legacy, and storage forms authorable in Rivencraft.
+        add(values, 200, "emerald_block");
+        add(values, 750, "gold_block", "raw_gold_block");
+        add(values, 4000, "ancient_debris");
+        add(values, 60, "iron_block", "raw_iron_block");
+        add(values, 8000, "netherite_block");
+        return Map.copyOf(values);
+    }
+
+    private static void add(Map<ResourceLocation, Integer> values, int weight, String... paths) {
+        for (String path : paths) values.put(ResourceLocation.withDefaultNamespace(path), weight);
+    }
+
+    private record Pending(ServerLevel level, LevelChunk chunk) {}
+}

src/main/java/net/dnorberg/rivencraft/book/AgeBlockProfileSavedData.java

@@ -0,0 +1,89 @@
+package net.dnorberg.rivencraft.book;
+
+import java.util.HashMap;
+import java.util.Map;
+import net.minecraft.core.HolderLookup;
+import net.minecraft.core.registries.BuiltInRegistries;
+import net.minecraft.nbt.CompoundTag;
+import net.minecraft.nbt.ListTag;
+import net.minecraft.resources.ResourceLocation;
+import net.minecraft.server.level.ServerLevel;
+import net.minecraft.util.datafix.DataFixTypes;
+import net.minecraft.world.level.ChunkPos;
+import net.minecraft.world.level.chunk.LevelChunk;
+import net.minecraft.world.level.saveddata.SavedData;
+
+/** Persistent, bounded samples of generated block abundance for one dimension. */
+public final class AgeBlockProfileSavedData extends SavedData {
+    static final int MIN_AGE_SAMPLES = 401;
+    static final int MIN_BASELINE_SAMPLES = 500;
+    static final int MAX_SAMPLES = 1024;
+    private static final Factory<AgeBlockProfileSavedData> FACTORY = new Factory<>(
+            AgeBlockProfileSavedData::new, AgeBlockProfileSavedData::load, DataFixTypes.SAVED_DATA_MAP_DATA);
+
+    private final Map<Long, Map<ResourceLocation, Integer>> samples = new HashMap<>();
+    private final Map<ResourceLocation, Long> totals = new HashMap<>();
+
+    AgeBlockProfileSavedData() {}
+
+    static AgeBlockProfileSavedData get(ServerLevel level) {
+        return level.getDataStorage().computeIfAbsent(FACTORY, "rivencraft_block_profile");
+    }
+
+    int count() { return samples.size(); }
+
+    Map<ResourceLocation, Long> totals() { return Map.copyOf(totals); }
+
+    boolean sample(LevelChunk chunk) {
+        if (samples.size() >= MAX_SAMPLES || samples.containsKey(chunk.getPos().toLong())) return false;
+        Map<ResourceLocation, Integer> counts = new HashMap<>();
+        for (var section : chunk.getSections()) {
+            if (section.hasOnlyAir()) continue;
+            section.getStates().count((state, amount) -> {
+                ResourceLocation id = BuiltInRegistries.BLOCK.getKey(state.getBlock());
+                if (AgeBlockInstability.weight(id) > 0) counts.merge(id, amount, Integer::sum);
+            });
+        }
+        add(chunk.getPos(), counts);
+        return true;
+    }
+
+    void add(ChunkPos pos, Map<ResourceLocation, Integer> counts) {
+        if (samples.size() >= MAX_SAMPLES || samples.containsKey(pos.toLong())) return;
+        samples.put(pos.toLong(), Map.copyOf(counts));
+        counts.forEach((id, amount) -> totals.merge(id, amount.longValue(), Long::sum));
+        setDirty();
+    }
+
+    @Override
+    public CompoundTag save(CompoundTag tag, HolderLookup.Provider registries) {
+        ListTag entries = new ListTag();
+        for (var sample : samples.entrySet()) {
+            CompoundTag entry = new CompoundTag();
+            entry.putLong("Chunk", sample.getKey());
+            CompoundTag blocks = new CompoundTag();
+            sample.getValue().forEach((id, amount) -> blocks.putInt(id.toString(), amount));
+            entry.put("Blocks", blocks);
+            entries.add(entry);
+        }
+        tag.put("Samples", entries);
+        return tag;
+    }
+
+    static AgeBlockProfileSavedData load(CompoundTag tag, HolderLookup.Provider registries) {
+        AgeBlockProfileSavedData data = new AgeBlockProfileSavedData();
+        ListTag entries = tag.getList("Samples", CompoundTag.TAG_COMPOUND);
+        for (int index = 0; index < Math.min(entries.size(), MAX_SAMPLES); index++) {
+            CompoundTag entry = entries.getCompound(index);
+            CompoundTag blocks = entry.getCompound("Blocks");
+            Map<ResourceLocation, Integer> counts = new HashMap<>();
+            for (String key : blocks.getAllKeys()) {
+                ResourceLocation id = ResourceLocation.tryParse(key);
+                if (id != null && AgeBlockInstability.weight(id) > 0 && blocks.getInt(key) > 0)
+                    counts.put(id, blocks.getInt(key));
+            }
+            data.add(new ChunkPos(entry.getLong("Chunk")), counts);
+        }
+        return data;
+    }
+}

src/main/java/net/dnorberg/rivencraft/book/AgeEnvironmentalProviders.java

@@ -80,7 +80,7 @@ public final class AgeEnvironmentalProviders {
             }
             case "erosion" -> {
                 if (!RivencraftConfig.erosionEnabled() || !AgeHazardProviders.canMutate(level)
-                        || age.instability().score() < InstabilityProviderCatalog.Deck.DESTRUCTIVE.entryCost()
+                        || AgeBlockInstability.effectiveScore(level, age) < InstabilityProviderCatalog.Deck.DESTRUCTIVE.entryCost()
                         || !(player.pick(6.0, 0.0F, false) instanceof BlockHitResult hit)) yield 0;
                 BlockPos pos = hit.getBlockPos();
                 yield erodeAt(context, pos) ? 1 : 0;
@@ -94,10 +94,10 @@ public final class AgeEnvironmentalProviders {
     }
 
     static void tickPlanned(ServerLevel level, AgeDefinition age, long tick) {
-        List<AgeInstabilityPlan.ProviderLevel> cards = age.instabilityPlan().providers().stream()
+        List<AgeInstabilityPlan.ProviderLevel> cards = AgeBlockInstability.effectivePlan(level, age).providers().stream()
                 .filter(card -> isEnvironmental(card.id())).toList();
         boolean optInErosion = RivencraftConfig.erosionEnabled()
-                && age.instability().score() >= InstabilityProviderCatalog.Deck.DESTRUCTIVE.entryCost();
+                && AgeBlockInstability.effectiveScore(level, age) >= InstabilityProviderCatalog.Deck.DESTRUCTIVE.entryCost();
         if (cards.isEmpty() && !optInErosion) return;
         List<ChunkPos> chunks = AgeHazardProviders.loadedChunksNearPlayers(level,
                 RivencraftConfig.hazardsMaxChunks());

src/main/java/net/dnorberg/rivencraft/book/AgeHazardProviders.java

@@ -8,6 +8,7 @@ import java.util.Optional;
 import java.util.Random;
 import java.util.Set;
 import java.util.UUID;
+import java.util.function.Predicate;
 import net.dnorberg.rivencraft.Rivencraft;
 import net.dnorberg.rivencraft.config.RivencraftConfig;
 import net.minecraft.core.BlockPos;
@@ -56,7 +57,7 @@ public final class AgeHazardProviders {
     /** Roll every selected hazard card each scheduler pass, independently of other providers. */
     static void tickPlanned(ServerLevel level, AgeDefinition age, long tick) {
         if (!RivencraftConfig.hazardsEnabled()) return;
-        List<AgeInstabilityPlan.ProviderLevel> hazards = age.instabilityPlan().providers().stream()
+        List<AgeInstabilityPlan.ProviderLevel> hazards = AgeBlockInstability.effectivePlan(level, age).providers().stream()
                 .filter(provider -> isHazard(provider.id())).toList();
         if (hazards.isEmpty()) return;
         List<ChunkPos> chunks = loadedChunksNearPlayers(level, RivencraftConfig.hazardsMaxChunks());
@@ -69,18 +70,27 @@ public final class AgeHazardProviders {
     }
 
     static List<ChunkPos> loadedChunksNearPlayers(ServerLevel level, int maximum) {
+        List<ChunkPos> players = level.players().stream()
+                .sorted(Comparator.comparing(Entity::getUUID))
+                .map(ServerPlayer::chunkPosition).toList();
+        return candidateChunks(players, maximum,
+                chunk -> level.getChunkSource().hasChunk(chunk.x, chunk.z));
+    }
+
+    /** Pure candidate selection; the caller's predicate must only report already-loaded chunks. */
+    static List<ChunkPos> candidateChunks(List<ChunkPos> players, int maximum,
+                                           Predicate<ChunkPos> loaded) {
+        if (maximum <= 0) return List.of();
         Set<ChunkPos> chunks = new LinkedHashSet<>();
-        List<ServerPlayer> players = level.players().stream()
-                .sorted(Comparator.comparing(Entity::getUUID)).toList();
         for (int radius = 0; radius <= 4; radius++) {
             for (int dx = -radius; dx <= radius; dx++) {
                 for (int dz = -radius; dz <= radius; dz++) {
                     if (Math.max(Math.abs(dx), Math.abs(dz)) != radius) continue;
-                    for (ServerPlayer player : players) {
-                        ChunkPos center = player.chunkPosition();
+                    for (ChunkPos center : players) {
                         int x = center.x + dx;
                         int z = center.z + dz;
-                        if (level.getChunkSource().hasChunk(x, z)) chunks.add(new ChunkPos(x, z));
+                        ChunkPos candidate = new ChunkPos(x, z);
+                        if (loaded.test(candidate)) chunks.add(candidate);
                         if (chunks.size() >= maximum) return List.copyOf(chunks);
                     }
                 }
@@ -200,7 +210,8 @@ public final class AgeHazardProviders {
     static void explodeBounded(ServerLevel level, AgeDefinition age, ChunkPos chunk, BlockPos pos,
             boolean blockDamage, boolean playerDamage, boolean ignite, int maxBlocks, int maxEntities,
             int maxDamage, int radius) {
-        boolean grief = canMutate(level) && blockDamage && maxBlocks > 0;
+        boolean grief = destructiveBlocksAllowed(RivencraftConfig.instabilityWorldMutation(),
+                level.getGameRules().getBoolean(GameRules.RULE_MOBGRIEFING), blockDamage, maxBlocks);
         boolean fire = grief && ignite
                 && level.getGameRules().getBoolean(GameRules.RULE_DOFIRETICK);
         Explosion explosion = level.explode(null, null, new BoundedExplosion(level, age, chunk, grief,
@@ -239,6 +250,19 @@ public final class AgeHazardProviders {
                 && level.getGameRules().getBoolean(GameRules.RULE_MOBGRIEFING);
     }
 
+    static boolean destructiveBlocksAllowed(boolean worldMutation, boolean mobGriefing,
+                                            boolean blockDamage, int maxBlocks) {
+        return worldMutation && mobGriefing && blockDamage && maxBlocks > 0;
+    }
+
+    static boolean protectedBlock(ServerLevel level, AgeDefinition age, BlockPos pos, BlockState state) {
+        return state.isAir() || state.hasBlockEntity() || state.is(Blocks.TNT)
+                || state.is(AgeDecayProviders.PROTECTED) || state.is(BlockTags.PORTALS)
+                || AgeDecayProviders.isSpawnProtected(age, pos)
+                || state.getDestroySpeed(level, pos) < 0
+                || BuiltInRegistries.BLOCK.getKey(state.getBlock()).getNamespace().equals(Rivencraft.MOD_ID);
+    }
+
     private static boolean eligibleEntity(Entity entity) {
         return eligibleEntity(entity, RivencraftConfig.hazardsPlayerDamage());
     }
@@ -287,12 +311,7 @@ public final class AgeHazardProviders {
         @Override
         public boolean shouldBlockExplode(Explosion explosion, BlockGetter reader, BlockPos pos,
                 BlockState state, float power) {
-            if (!grief || !inLoadedChunk(pos) || state.isAir() || state.hasBlockEntity()
-                    || state.is(Blocks.TNT)
-                    || state.is(AgeDecayProviders.PROTECTED) || state.is(BlockTags.PORTALS)
-                    || AgeDecayProviders.isSpawnProtected(age, pos)
-                    || state.getDestroySpeed(level, pos) < 0
-                    || BuiltInRegistries.BLOCK.getKey(state.getBlock()).getNamespace().equals(Rivencraft.MOD_ID)) return false;
+            if (!grief || !inLoadedChunk(pos) || protectedBlock(level, age, pos, state)) return false;
             if (approved.contains(pos)) return true;
             if (approved.size() >= maxBlocks) return false;
             var actor = FakePlayerFactory.getMinecraft(level);

src/main/java/net/dnorberg/rivencraft/book/AgeInstability.java

@@ -13,7 +13,7 @@ import net.minecraft.resources.ResourceLocation;
 
 /** Frozen, server-owned score. Only new Age creation consults the current symbol catalog. */
 public record AgeInstability(int version, int score, List<Contribution> breakdown) {
-    public static final int CURRENT_VERSION = 1;
+    public static final int CURRENT_VERSION = 2;
     private static final int BRIGHT_LIGHTING_COST = 500;
     private static final int EXCESS_LEGACY_STRUCTURE_COST = 100;
     private static final int FORCED_STRUCTURE_BIOME_COST = 100;
@@ -35,7 +35,8 @@ public record AgeInstability(int version, int score, List<Contribution> breakdow
     );
 
     public AgeInstability {
-        if (version != CURRENT_VERSION) throw new IllegalArgumentException("Unsupported instability version " + version);
+        if (version < 1 || version > CURRENT_VERSION)
+            throw new IllegalArgumentException("Unsupported instability version " + version);
         breakdown = List.copyOf(breakdown);
         if (score < 0 || score != breakdown.stream().mapToInt(Contribution::points).sum()) {
             throw new IllegalArgumentException("Instability score does not match breakdown");
@@ -44,7 +45,7 @@ public record AgeInstability(int version, int score, List<Contribution> breakdow
 
     /** Pre-scoring saves are explicitly neutral, never rescored from current data packs. */
     public static AgeInstability legacyNeutral() {
-        return new AgeInstability(CURRENT_VERSION, 0,
+        return new AgeInstability(1, 0,
                 List.of(new Contribution("legacy_neutral", -1, 0, "Age predates frozen instability scoring")));
     }
 

src/main/java/net/dnorberg/rivencraft/book/AgeInstabilityRuntime.java

@@ -52,7 +52,7 @@ public final class AgeInstabilityRuntime {
         if (!admitted(state.eligible, level.dimension().location(), tick / cooldown,
                 RivencraftConfig.instabilityMaxAges())) return;
         AgeDefinition age = AgeRegistrySavedData.get(level).findByDimension(level.dimension().location()).orElse(null);
-        if (age == null || age.instabilityPlan().providers().isEmpty()
+        if (age == null || AgeBlockInstability.effectivePlan(level, age).providers().isEmpty()
                 || !AgeInstabilityControls.get(level).enabled(age.id())) return;
         // Legacy's per-chunk hazards must not wait for the rotating two-provider sample.
         AgeHazardProviders.tickPlanned(level, age, tick);
@@ -61,7 +61,7 @@ public final class AgeInstabilityRuntime {
         if (chunks.isEmpty()) return;
         Budget budget = new Budget(RivencraftConfig.instabilityMaxActions());
         Context context = new Context(level, age, chunks, tick, budget);
-        List<AgeInstabilityPlan.ProviderLevel> providers = age.instabilityPlan().providers();
+        List<AgeInstabilityPlan.ProviderLevel> providers = AgeBlockInstability.effectivePlan(level, age).providers();
         int first = (int) Math.floorMod(tick / cooldown + age.seed(), providers.size());
         int ran = 0;
         for (int offset = 0; offset < providers.size() && ran < RivencraftConfig.instabilityMaxProviders()
@@ -84,8 +84,8 @@ public final class AgeInstabilityRuntime {
             }
             return false;
         }
-        if (!RivencraftConfig.instabilityProviderEnabled(id)) return false;
-        if (handler.worldMutating() && !RivencraftConfig.instabilityWorldMutation()) return false;
+        if (!policyAllowsProvider(RivencraftConfig.instabilityProviderEnabled(id),
+                RivencraftConfig.instabilityWorldMutation(), handler.worldMutating())) return false;
         long retryAfter = FAILURES.computeIfAbsent(context.level(), ignored -> new HashMap<>())
                 .getOrDefault(id, 0L);
         if (context.serverTick() < retryAfter) return false;
@@ -111,6 +111,11 @@ public final class AgeInstabilityRuntime {
         return id.getNamespace().equals(Rivencraft.MOD_ID) && id.getPath().startsWith("age/");
     }
 
+    static boolean policyAllowsProvider(boolean providerEnabled, boolean worldMutation,
+                                        boolean mutatingHandler) {
+        return providerEnabled && (!mutatingHandler || worldMutation);
+    }
+
     /** Current runtime state, distinct from the Age's immutable score and provider selection. */
     public static String providerStatus(ServerLevel level, AgeDefinition age, ResourceLocation id) {
         if (!RivencraftConfig.instabilityEnabled()) return "global config off";
@@ -159,7 +164,7 @@ public final class AgeInstabilityRuntime {
         for (ServerLevel level : server.getAllLevels()) {
             ResourceLocation id = level.dimension().location();
             if (isAgeDimension(id) && !level.players().isEmpty()
-                    && registry.findByDimension(id).filter(age -> !age.instabilityPlan().providers().isEmpty())
+                    && registry.findByDimension(id).filter(age -> !AgeBlockInstability.effectivePlan(level, age).providers().isEmpty())
                     .filter(age -> AgeInstabilityControls.get(level).enabled(age.id()))
                     .isPresent()) eligible.add(id);
         }

src/main/java/net/dnorberg/rivencraft/book/Milestone6RegressionGameTests.java

@@ -0,0 +1,126 @@
+package net.dnorberg.rivencraft.book;
+
+import java.util.List;
+import java.util.Map;
+import java.util.Set;
+import java.util.UUID;
+import net.dnorberg.rivencraft.registry.ModBlocks;
+import net.minecraft.core.BlockPos;
+import net.minecraft.gametest.framework.GameTest;
+import net.minecraft.gametest.framework.GameTestHelper;
+import net.minecraft.world.level.ChunkPos;
+import net.minecraft.world.level.block.Blocks;
+import net.neoforged.neoforge.gametest.GameTestHolder;
+import net.neoforged.neoforge.gametest.PrefixGameTestTemplate;
+
+/** Focused safety gaps; score and migration cases remain in the default suite. */
+@GameTestHolder("rivencraft_archive_instability")
+@PrefixGameTestTemplate(false)
+public final class Milestone6RegressionGameTests {
+    private Milestone6RegressionGameTests() {}
+
+    @GameTest(template = "empty")
+    public static void multiplayerCandidatesStayLoadedDeduplicatedAndCapped(GameTestHelper helper) {
+        ChunkPos first = new ChunkPos(0, 0);
+        ChunkPos second = new ChunkPos(8, 0);
+        ChunkPos unloaded = new ChunkPos(0, 1);
+        Set<ChunkPos> loaded = Set.of(first, second, new ChunkPos(1, 0));
+        var selected = AgeHazardProviders.candidateChunks(List.of(first, second, first), 2, loaded::contains);
+        helper.assertValueEqual(selected, List.of(first, second),
+                "Two players in different loaded areas must each contribute one candidate before expansion");
+        helper.assertTrue(!selected.contains(unloaded) && selected.stream().distinct().count() == 2,
+                "Unloaded and duplicate chunks must never enter the effect context");
+        helper.assertValueEqual(AgeHazardProviders.candidateChunks(List.of(first, second), 1, loaded::contains),
+                List.of(first), "The per-attempt chunk cap must be obeyed with multiple players");
+        helper.assertTrue(AgeHazardProviders.candidateChunks(List.of(first), 0, loaded::contains).isEmpty(),
+                "A zero work budget must not inspect chunks");
+        helper.succeed();
+    }
+
+    @GameTest(template = "empty")
+    public static void disablingEffectsCannotRerollFrozenPlan(GameTestHelper helper) {
+        AgeInstability score = new AgeInstability(AgeInstability.CURRENT_VERSION, 20_000,
+                List.of(new AgeInstability.Contribution("fixture", -1, 20_000, "regression score")));
+        AgeInstabilityPlan plan = AgeInstabilityPlan.select(score, 741L);
+        UUID id = UUID.randomUUID();
+        AgeDefinition age = new AgeDefinition(id, "Policy fixture", 741L, AgeGenerationProfiles.STANDARD,
+                AgeDefinition.CURRENT_GENERATION_VERSION, 0L, AgeDefinition.dimensionId(id), null,
+                AgeTraits.LEGACY_DEFAULTS, null, null, List.of(), score, plan);
+        AgeInstabilityControls controls = new AgeInstabilityControls();
+        controls.setEnabled(id, false);
+        helper.assertTrue(!controls.enabled(id) && controls.enabled(UUID.randomUUID()),
+                "An Age override must not spill into another Age");
+        helper.assertTrue(!AgeInstabilityRuntime.policyAllowsProvider(false, true, false)
+                        && !AgeInstabilityRuntime.policyAllowsProvider(true, false, true)
+                        && AgeInstabilityRuntime.policyAllowsProvider(true, false, false),
+                "Per-provider disable and world-mutation disable must block only their intended effects");
+        controls.setEnabled(id, true);
+        helper.assertValueEqual(age.instability(), score, "Controls must not change the frozen score");
+        helper.assertValueEqual(age.instabilityPlan(), plan, "Controls must not reroll the frozen provider plan");
+        helper.succeed();
+    }
+
+    @GameTest(template = "empty")
+    public static void disabledGriefAndProtectedBlocksStayUntouched(GameTestHelper helper) {
+        helper.assertTrue(!AgeHazardProviders.destructiveBlocksAllowed(false, true, true, 16)
+                        && !AgeHazardProviders.destructiveBlocksAllowed(true, false, true, 16)
+                        && !AgeHazardProviders.destructiveBlocksAllowed(true, true, false, 16)
+                        && !AgeHazardProviders.destructiveBlocksAllowed(true, true, true, 0),
+                "Every disabled destructive policy must prevent block damage");
+        helper.assertTrue(AgeHazardProviders.destructiveBlocksAllowed(true, true, true, 1),
+                "The enabled path must still have a bounded block budget");
+        BlockPos spawn = helper.absolutePos(new BlockPos(1, 1, 1));
+        BlockPos far = spawn.offset(12, 0, 12);
+        UUID id = UUID.randomUUID();
+        AgeDefinition age = new AgeDefinition(id, "Protected fixture", 1L, AgeGenerationProfiles.STANDARD,
+                AgeDefinition.CURRENT_GENERATION_VERSION, 0L, AgeDefinition.dimensionId(id), spawn,
+                AgeTraits.LEGACY_DEFAULTS);
+        var level = helper.getLevel();
+        helper.assertTrue(AgeHazardProviders.protectedBlock(level, age, spawn, Blocks.STONE.defaultBlockState()),
+                "Arrival blocks must be protected from an explosion");
+        for (var state : List.of(Blocks.CHEST.defaultBlockState(), Blocks.NETHER_PORTAL.defaultBlockState(),
+                Blocks.BEDROCK.defaultBlockState(), ModBlocks.CLOUD_PLATFORM.get().defaultBlockState())) {
+            helper.assertTrue(AgeHazardProviders.protectedBlock(level, age, far, state),
+                    "Block entities, portals, unbreakable blocks, and Rivencraft blocks must be protected");
+        }
+        helper.assertTrue(!AgeHazardProviders.protectedBlock(level, age, far, Blocks.STONE.defaultBlockState()),
+                "Ordinary stone outside the protected arrival area remains eligible");
+        helper.succeed();
+    }
+
+    @GameTest(template = "empty")
+    public static void generatedDiamondBlocksIncreaseLiveInstability(GameTestHelper helper) {
+        var diamond = net.minecraft.resources.ResourceLocation.parse("minecraft:diamond_block");
+        var ore = net.minecraft.resources.ResourceLocation.parse("minecraft:diamond_ore");
+        helper.assertValueEqual(AgeBlockInstability.score(Map.of(diamond, 4000L), 400,
+                Map.of(ore, 2000L), 500), 0,
+                "Legacy's 400-chunk threshold must gate the live block component");
+        int score = AgeBlockInstability.score(Map.of(diamond, 4010L, ore, 1604L), 401,
+                Map.of(ore, 2000L), 500);
+        helper.assertValueEqual(score, 40_000,
+                "Ten generated diamond blocks per sampled chunk add substantial instability");
+        helper.assertValueEqual(AgeBlockInstability.score(Map.of(ore, 1604L), 401,
+                Map.of(ore, 2000L), 500), 0,
+                "Natural ore abundance equal to the baseline must remain free");
+        var effective = new AgeInstability(AgeInstability.CURRENT_VERSION, score,
+                List.of(new AgeInstability.Contribution("block_profile", -1, score, "sampled excess")));
+        helper.assertTrue(!AgeInstabilityPlan.select(effective, 64L).providers().isEmpty(),
+                "A new effective score must unlock providers without replacing the authored base plan");
+        helper.succeed();
+    }
+
+    @GameTest(template = "empty")
+    public static void blockProfileSamplesPersistWithoutDoubleCounting(GameTestHelper helper) {
+        var data = new AgeBlockProfileSavedData();
+        var diamond = net.minecraft.resources.ResourceLocation.parse("minecraft:diamond_block");
+        data.add(new ChunkPos(3, 4), Map.of(diamond, 12));
+        data.add(new ChunkPos(3, 4), Map.of(diamond, 100));
+        helper.assertValueEqual(data.count(), 1, "A reloaded chunk must not be sampled twice");
+        helper.assertValueEqual(data.totals().get(diamond), 12L, "Duplicate loads cannot inflate abundance");
+        var restored = AgeBlockProfileSavedData.load(data.save(new net.minecraft.nbt.CompoundTag(),
+                helper.getLevel().registryAccess()), helper.getLevel().registryAccess());
+        helper.assertValueEqual(restored.count(), 1, "The profiled chunk set must survive restart");
+        helper.assertValueEqual(restored.totals(), data.totals(), "Block counts must survive restart");
+        helper.succeed();
+    }
+}

src/main/java/net/dnorberg/rivencraft/command/RivencraftCommands.java

@@ -132,12 +132,28 @@ public final class RivencraftCommands {
     private static int inspectInstability(CommandSourceStack source, String requestedDimension) {
         AgeDefinition age = resolveAge(source, requestedDimension);
         if (age == null) return 0;
+        var ageLevel = source.getServer().getLevel(net.minecraft.resources.ResourceKey.create(
+                net.minecraft.core.registries.Registries.DIMENSION, age.dimensionId()));
+        int blockScore = ageLevel == null ? 0 : net.dnorberg.rivencraft.book.AgeBlockInstability.score(ageLevel, age);
+        var selectedPlan = ageLevel == null ? age.instabilityPlan()
+                : net.dnorberg.rivencraft.book.AgeBlockInstability.effectivePlan(ageLevel, age);
         var totals = age.instability().totals();
         source.sendSuccess(() -> Component.literal(age.name() + " — " + age.dimensionId()), false);
         source.sendSuccess(() -> Component.literal("Instability: base " + totals.baseScore()
                 + ", stability bonus " + totals.stabilityBonus()
                 + ", penalty " + totals.instabilityPenalty()
-                + ", effective " + totals.effectiveScore()), false);
+                + ", profiled blocks +" + blockScore
+                + ", effective " + Math.min(Integer.MAX_VALUE,
+                        (long) totals.effectiveScore() + blockScore)), false);
+        if (age.instability().version() >= 2) {
+            int ageSamples = ageLevel == null ? 0
+                    : net.dnorberg.rivencraft.book.AgeBlockInstability.sampledChunks(ageLevel);
+            int baselineSamples = net.dnorberg.rivencraft.book.AgeBlockInstability.sampledChunks(
+                    source.getServer().overworld());
+            source.sendSuccess(() -> Component.literal("Block profile: Age " + ageSamples
+                    + "/401, Overworld baseline " + baselineSamples + "/500"
+                    + (ageLevel == null ? " (Age unloaded)" : "")), false);
+        }
         boolean enabled = AgeInstabilityControls.get(source.getLevel()).enabled(age.id());
         source.sendSuccess(() -> Component.literal("Runtime: " + (enabled ? "Age enabled" : "Age disabled")
                 + ", global " + (RivencraftConfig.instabilityEnabled() ? "enabled" : "disabled")
@@ -147,12 +163,13 @@ public final class RivencraftCommands {
         age.instability().breakdown().forEach(part -> source.sendSuccess(() -> Component.literal(
                 "  " + (part.pageIndex() < 0 ? "Age" : "page " + (part.pageIndex() + 1))
                         + " +" + part.points() + " " + part.reason() + ": " + part.detail()), false));
-        source.sendSuccess(() -> Component.literal("Selected providers (saved plan v"
-                + age.instabilityPlan().version() + "): " + age.instabilityPlan().providers().size()), false);
-        age.instabilityPlan().providers().forEach(provider -> source.sendSuccess(() -> Component.literal(
+        source.sendSuccess(() -> Component.literal("Selected providers (effective plan v"
+                + selectedPlan.version() + "): " + selectedPlan.providers().size()), false);
+        selectedPlan.providers().forEach(provider -> source.sendSuccess(() -> Component.literal(
                 "  " + provider.id() + " level " + provider.level() + " — "
-                        + AgeInstabilityRuntime.providerStatus(source.getLevel(), age, provider.id())), false));
-        if (age.instabilityPlan().providers().isEmpty()) source.sendSuccess(() -> Component.literal(
+                        + AgeInstabilityRuntime.providerStatus(ageLevel == null ? source.getLevel() : ageLevel,
+                        age, provider.id())), false));
+        if (selectedPlan.providers().isEmpty()) source.sendSuccess(() -> Component.literal(
                 "  No providers selected; an old neutral Age stays neutral."), false);
         source.sendSuccess(() -> Component.literal("Limits: cooldown " + RivencraftConfig.instabilityCooldown()
                 + " ticks, " + RivencraftConfig.instabilityMaxAges() + " Ages/tick, "
@@ -161,7 +178,7 @@ public final class RivencraftCommands {
                 + RivencraftConfig.instabilityMaxLevel()), false);
         source.sendSuccess(() -> Component.literal("Mutable player bonuses: disabled (no active Legacy registration)"),
                 false);
-        return totals.effectiveScore();
+        return (int) Math.min(Integer.MAX_VALUE, (long) totals.effectiveScore() + blockScore);
     }
 
     private static java.util.concurrent.CompletableFuture<com.mojang.brigadier.suggestion.Suggestions> suggestAges(