Java Edition 21w39a

21w39a is the third snapshot for Java Edition 1.18, released on September 29, 2021, which add new advancements and fixes bugs.

Starting from this snapshot, players can open old worlds again. This does not only mean it is the first version which makes it possible to convert old worlds with lower limit y=0 to the new y=-64, but it means also that high caution is needed and backups are recommended when converting important old worlds, because the old chunks do yet not generate anything under their bedrock level: from -64 to -1 it is just void, only the new chunks get the new deep generation.

Gameplay

 * Advancements
 * Added four new advancements:
 * Caves & Cliffs
 * Fall from the top to the bottom of the Overworld
 * Feels like home
 * Ride a strider on lava for 50 blocks in the Overworld
 * Star Trader
 * Trade with a villager at the build height limit
 * Sound of Music
 * Play music with a jukebox in a meadow biome
 * Added new advancement triggers.
 * Triggered when a player lands after falling.
 * Triggered for every tick when player rides in lava.
 * Triggered for every tick when player rides in lava.
 * Triggered for every tick when player rides in lava.

General

 * Loot tables
 * Added new loot table function, to set tag on any item.
 * Has following parameters:
 * : Potion ID

Mobs

 * Drowned
 * Now can spawn in aquifers inside dripstone caves.


 * Zombie
 * No longer spawns in dripstone caves.

World generation

 * Lofty Peaks, Snowcapped Peaks and Stony Peaks
 * Its small mountains are more jagged now.


 * Meadow
 * Trees in Meadows now always contain a bee nest.

Gameplay

 * Advancements
 * "Light as a Rabbit" now has "Sweet Dreams" as its parent instead of "Adventure".

General

 * Buried Treasure
 * Buried treasure chests can now contain water breathing potions.


 * Chunk format
 * Chunk’s &  have moved to a container structure in.
 * Chunk’s are now paletted and live in a similar container structure in.
 * Chunk’s is now  instead of.


 * Effects
 * Redesigned how effects look in the inventory screen.
 * Can display while recipe book is showing.
 * The list of effects are now shown to the right of the player's inventory, instead of the left side.
 * When the inventory effects list is visible, it will be hidden from the game view to reduce screen clutter.
 * There’s now two modes of seeing the effect list: compact and classic:
 * Classic is the pre-existing list of effects, one after another.
 * Compact is a single icon for each effect, suitable for small screen estate.
 * The game will automatically switch between the two looks to suit the available screen estate.


 * Options
 * Changed default brightness to 50.


 * Resource packs
 * Resource pack version number is now 8, as the following has been changed:
 * inventory.png now contains an extra sprite for a thin-layout version of the effect list in the inventory.


 * Server
 * now bundles individual libraries instead of merging all the files into single archive.
 * This change is meant to solve certain problems related to Java modules.
 * On startup, will unpack libraries into a directory configured by  (default: working directory).
 * To run different main class than server, use property.

Fixes

 * Other
 * Removed generic snapshot tooltips from incompatible worlds (except for worlds created in experimental snapshots).

Video
Videos made by slicedlime: