# 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` |
| Optional-mod material weights, block overrides, and old profile migration | `Milestone6RegressionGameTests.commonModdedMaterialWeightsStayBounded`, `blockProfileSamplesPersistWithoutDoubleCounting` |
| Ordered celestial modifier consumption, repeated modifiers, and dangling +100 per kind | `WritingGrammarGameTests.orderedGrammarAcceptsPartialWritingAndDiagnosesInvalidSequences`; `EnvironmentWritingGameTests.celestialModifiersFollowWrittenOrder` |

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.
- Version-3 plans keep their previous stage-sorted celestial interpretation and
  frozen writing cost. Only new version-4 plans consume period/phase modifiers
  in authored order and charge a trailing modifier once per pending kind.
- 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.
   Separately, install a mod with common-tagged ores/storage blocks or source
   fluids. Compare a material-rich Age with an ordinary Age after the profile
   thresholds are reached; the installed mod's recognized blocks should affect
   the result without a Rivencraft allowlist. Then remove that optional mod in
   a disposable copy and confirm Rivencraft still starts. Test a single
   `block_weight_overrides` entry and a zero-weight exclusion. This remains a
   player-run scenario, not an automated pass.
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.
The player reported an in-game pass for the 0.5.8.18 candidate on 2026-10-12.
That is a release-slice acceptance report, not a claim that every expanded
matrix row below was individually exercised.

### Regression run record

For each row, record pass/fail, world seed, Age name, Rivencraft version,
optional-mod versions, and a short observation. "Not run" is intentional
until a player completes the in-game check; a successful build is not a pass.

| Area | Specific manual observation | Status |
| --- | --- | --- |
| New vs reused book | Dimension ID, score, and providers do not reroll | Not run |
| Full process restart | Re-enter two Ages; saved traits, score, plan, and cooldowns persist | Not run |
| Multiplayer isolation | Two Age players receive effects; Overworld player does not | Not run |
| Loaded-chunk scope | Departing players permit unloading; hazards do not reach old chunks | Not run |
| Controls | Global, per-Age, mutation, and provider toggles suppress effects without reroll | Not run |
| Protected blocks | Explosion/decay/erosion spare arrival platforms, portals, and block entities | Not run |
| Hazard visuals | Lightning, explosions, decay, status, burning, meteor, and erosion each behave when selected | Not run |
| Third-party biomes | TerraBlender biome pages and cave classification survive Age creation/restart | Not run |
| Optional integrations absent | Mod launches without JEI, Create/Ponder, Immersive Portals, Serene Seasons, or biome mods | Not run |
| Optional integrations present | JEI pages/recipes, preview backends, seasonal behavior, and ambient sound work | Not run |
| Optional-mod materials | Tagged ore/storage/source-fluid samples change live profile automatically | Not run |
| Material overrides | Positive and zero `block_weight_overrides` values affect only named blocks | Not run |
| Removed optional mod | Disposable copy launches without the mod; unknown sampled IDs stay serialized | Not run |
| Removed symbol/handler | Frozen score and provider plan survive when nonessential data is removed | Not run |
| Ordered modifiers | Five book-order cases below produce expected time and dangling costs | Not run |

### Focused ordered-writing and optional-material checks for 0.5.8.18

Use `/rivencraft age instability` in each newly bound Age; old Ages retain
their original plan and score. Record each row as pass/fail with the Age name,
world seed, installed optional mods, and the command output. The ordered
modifier assertions are archived, not a claim that the stalled GameTest suite ran.

| Book pages after Link Panel, in exact order | Expected result | Result |
| --- | --- | --- |
| Half Length, Double Length, Normal Time | Length combines to 1.25×, no dangling cost | Not run in game |
| Normal Time, Zero Length | Sun keeps normal motion; one dangling +100 | Not run in game |
| Rising, Normal Time, Setting | Rising start phase; Setting dangles +100 | Not run in game |
| Half Length, Double Length, no celestial page | One combined pending length dangles +100; seeded clock remains | Not run in game |
| Normal Time, Zero Length, Normal Time | Last sun consumes Zero Length; duplicate celestial cost remains separate | Not run in game |

With a common-tagged ore/storage-block or source-fluid mod installed, bind
comparable material-rich and ordinary Ages and wait for profiling thresholds.
Verify the modded material contributes automatically, then restart and confirm
the score/profile remains consistent. On a disposable copy, remove the mod and
confirm Rivencraft launches without it; restore the mod before judging the
world's registry-dependent terrain. Also check a zero-weight override and a
positive override. These are optional-mod compatibility checks, not a new
required dependency.