25w42a — release journal

What 25w42a changed for data packs, measured against 25w41a, the build before it. Released 2025-10-14; development build — not a release.

⚠ Entries removed

5 registry entries were removed. A pack that names one of them will fail to parse where it does.

Formats

31 entries added and 5 removed across 6 registries.

Registry	Change	Added	Removed
`attribute_type`	new registry	`ambient_particles`, `ambient_sounds`, `background_music`, `bed_rule`, `boolean`, `color`, `float`, `particle`	—
`environment_attribute`	new registry	`audio/ambient_sounds`, `audio/background_music`, `audio/music_volume`, `gameplay/bed_rule`, `gameplay/can_start_raid`, `gameplay/fast_lava`, `gameplay/increased_fire_burnout`, `gameplay/nether_portal_spawns_piglin`, `gameplay/piglins_zombify`, `gameplay/respawn_anchor_works`, `gameplay/snow_golem_melts`, `gameplay/water_evaporates`, `visual/ambient_particles`, `visual/cloud_height`, `visual/cloud_opacity`, `visual/default_dripstone_particle`, `visual/extra_fog`, `visual/fog_color`, `visual/sky_color`, `visual/water_fog_color`, `visual/water_fog_radius`	—
`sound`	changed	`mob/nautilus/ride`	—
`sound_event`	changed	`entity.nautilus.riding`	—
`tag/enchantment`	changed	—	`exclusive_set/lunge`
`tag/worldgen/biome`	changed	—	`has_closer_water_fog`, `increased_fire_burnout`, `plays_underwater_music`, `snow_golem_melts`

That article's technical changes are grouped under these headings — open it for the detail:

misode/mcmeta — 25w42a summary — formats and registries, generated from the game’s own data.
minecraft.net — 25w42a — section names only.