# Environmental instability (#70)

The local Mystcraft Legacy 0.13.7.06 bytecode was audited for `EffectMeteor`, `EntityMeteor`, `EffectScorched`, `EffectErosion`, and their providers. The active deck registers `meteors` in destructive and `burning` (scorching) in harsh. Erosion's provider is present in bytecode but not registered in the active deck. Its old chunk-population lake routines are not run at Age creation in Rivencraft; ordinary authored lake features already own generation. The old erosion tick spread a neighboring water/lava or Forge fluid block into a random non-liquid position, excluding downward neighbors and block containers.

Rivencraft keeps the active `meteors` and `burning` provider IDs in frozen Age plans. Erosion does not become a deck card. For this test slice, `instability_erosion.enabled` defaults **on** as an explicit adaptation requested by the user. It runs only in Ages whose frozen instability score reaches the destructive deck threshold (10,000), and may be disabled independently. Existing Age plans are not rerolled.

Legacy's meteor spawned at Y=500, fell as a custom entity, broke blocks along its path, and made multiple large explosions on impact. Modern Ages can have different build heights and dynamic dimensions. Rivencraft instead records one bounded active descent per Age (16 globally), starting no more than 48 blocks above the loaded surface. Server particles show the trajectory and the byte-identical Legacy `entity/meteor/roar.ogg` plays near the impact. A single strength-3 impact reuses the capped explosion/protection hooks from #69. There is no persistent projectile entity or custom model; stopping/unloading a dimension cancels a descent rather than replaying it on restart. The saved per-Age attempt sequence and cooldown prevent immediate repeated rolls. The adaptation is intentionally less destructive than Legacy's chain of explosions.

Scorching checks at most eight loaded chunks and eight living-entity candidates per chunk per scheduler pass, igniting at most the configured target count. Targets must be open to sky; survival/adventure players are included by default as in Legacy, while creative/spectator players and spawn safety positions are excluded. Fire duration is four seconds per provider level, capped at twelve seconds. This affects entities, not blocks, and does not request distant chunks.

Erosion inspects at most eight already-loaded candidate positions per pass and can replace at most one safe block with an adjacent source fluid. It excludes block entities, protected/critical Rivencraft blocks, portals, spawn safety positions, and unloaded neighboring chunks. Break and place events with a fake player permit claim/protection hooks to veto a change; rejected placement is rolled back. World mutation and `mobGriefing` must also be enabled. The modern Y range is taken from the Age level rather than Legacy's fixed 0–127 sample.

The server config has independent meteor enable/block damage/player damage/fire/caps, scorching enable/player targeting/cap, and erosion enable switches. Meteor frequency preserves Legacy's 1/50,000 chance per chunk-tick across nearby loaded chunks, capped to one active descent per Age. Visual/audio effects still run when meteor block damage is disabled. No client-only class is loaded on a dedicated server. The reused roar sound is recorded in [asset provenance](ASSET_PROVENANCE.md); Legacy has no separate meteor texture in the supplied asset tree.

Operator checks in a loaded, sufficiently unstable Age: `/rivencraft age environment pulse meteor` starts one protected descent (200-tick cooldown), `/rivencraft age environment pulse burning` ignites the issuing survival player only when open to sky and outside spawn protection, and `/rivencraft age environment pulse erosion` converts the block being looked at if a source fluid touches its side or top. The burning test reports when rain or water would immediately extinguish the fire. Place water or lava next to a plain stone block and aim at the stone to test erosion. These commands refuse to run in the Overworld and still honor enable switches, protection hooks, and world-mutation policy. Natural meteor occurrence is intentionally rare, as in Legacy.