Java Edition 21w13a

21w13a is the fifteenth snapshot for Java Edition 1.17 released on March 31, 2021, which adds goats, light blocks, and makes tweaks to caves and ore blob generation.

Blocks

 * Light Block
 * A new waterloggable source of light, originally was a Bedrock Edition exclusive.
 * Behaves like air, and it is visible and targetable only when the item is held, similar to barriers.
 * Obtainable only with.
 * Right-click cycles light level.

Mobs

 * Goat
 * Spawn in Mountains.
 * Jump higher than regular mobs.
 * Can be tempted and bred using Wheat.
 * A bucket can be used to get milk.

General

 * Acessibility
 * Added an alternative solid black background color for the Mojang Studios loading screen, toggleable with the “Monochrome Logo” accessibility option.


 * Tags
 * Added the block tag.
 * Contains dirt, coarse dirt, podzol, and rooted dirt.
 * Added the block tag.
 * Contains snow, snow blocks, and powder snow.
 * Added the entity type tag.
 * Contains tropical fish, pufferfish, cod, squid, and glow squid, which were the previous contents of the entity type tag.
 * Added the entity type tag.
 * Contains striders, blazes, and magma cubes.
 * Added the entity type tag.
 * Contains strays, polar bears, and snow golems.

Blocks

 * Candle
 * Candles can now be extinguished by splash water bottles and by lingering water bottles.


 * Powder Snow
 * Powder snow’s durability/hardness was slightly increased.
 * Freeze time has decreased to 7 seconds and hurt frequency has decreased to 2 seconds.
 * Entities on fire now melt Powder Snow when colliding.
 * Increased vertical movement speed within Powder Snow.
 * Mobs now shake when they are fully frozen.


 * Rooted Dirt
 * The top texture is now randomly rotated.

Items

 * Leather Horse Armor now protects horses from freeze damage.

Mobs

 * Axolotl
 * Axolotls now spawn in underground water sources
 * Axolotls will now always chase after and attack squids, glow squids, tropical fish, cod, salmon, pufferfish, drowned, guardians, and elder guardians
 * Axolotls now have a two-minute cooldown after hunting non-hostile targets such as fish, squids, etc.
 * They will prioritize targeting hostile mobs first before hunting.
 * Blue, cyan, gold, and lucy axolotls have had the textures of the outlines on their tails slightly changed.
 * Cyan, gold, and lucy axolotls have had the textures of the frills on their head slightly changed.


 * Glow Squid
 * Glow squids now spawn in underground water sources.


 * Bee
 * Bees now see Flowering Azalea (and Flowering Azalea Leaves) as flowers.


 * Wandering Trader
 * Added the following trades to Wandering Trader:
 * Will sell 2 Pointed Dripstones for 1 emerald.
 * Will sell 2 Rooted Dirt for 1 emerald.
 * Will sell 2 Moss Blocks for 1 emerald.


 * Mason
 * Added the following trade to Mason:
 * Will sell 4 Dripstone blocks for 1 emerald.


 * Stray, Polar Bear and Snow Golem
 * Are now immune to freezing.


 * Blaze, Magma Cube, and Strider
 * Take increased freeze damage.


 * Skeleton
 * Skeletons converting to strays now only require the 7 seconds it takes for an entity to be fully frozen to begin converting, instead of the 30 seconds it took before.


 * Elder Guardians, Guardians, and Polar Bears
 * Now drop cooked cod or salmon instead of raw cod or salmon if on fire when killed or killed by a fire source.


 * Husks, Zombies, and Zombie Villagers
 * Now drop baked potatoes instead of normal potatoes if on fire when killed or killed by a fire source.

World generation

 * Made carvers less likely to be too flat to walk through.
 * Increased likelihood of megacaves (large cheese caves).
 * Reduced likelihood of toothpick pillars (tall 1-block thin pillars).
 * Other tweaks to make the cheese caves more varied.
 * Deepslate blobs can now be found between heights 0 and 16.
 * Dripstone clusters can now be found rarely in normal caves.
 * Slightly more iron.
 * Larger diamond blobs sometimes form.
 * Mineshafts
 * Increased the max length of pillars and chains.
 * Glow Berries can be found in Mineshaft chest minecarts.
 * Shipwrecks
 * Moss blocks can be found in chests.

Gameplay

 * Build limit
 * The message for letting the player know they are attempting to build beyond the build limit no longer says "blocks" at the end.


 * Advancements
 * Goats and axolotls are now required for "Two by Two".
 * Axoltls have always been available for "The Parrots and the Bats" and goats can now be used as well, though now changes were made to the advancement to let this happen.
 * The advancement for obtaining diamond armor is now capitalized as "Cover Me with Diamonds", as opposed to "Cover Me With Diamonds".

General

 * Code
 * Unused parts of code (unused static fields and methods) are no longer removed.
 * Although this does not affect the game itself, adds more info for modders.


 * Tags
 * Changed the block tags to use the  block tag, removing other mentions of dirt blocks from the tags.
 * Added all copper slab and stair variants to the block and item tags, respectively.
 * Added flowering azalea leaves and flowering azaleas to the block and item tags.
 * Changed the entity type tag to have the previous contents of the  tag, as well as adding elder guardians.
 * The previous contents of the tag have been added to.
 * Removed the entity type tag.
 * Added leather horse armor to the item tag.


 * Textures
 * Removed some unused textures, including:
 * The "calibrated sculk sensor" textures.
 * The texture for the zombie villager before 1.9.
 * The "arrow.png" placed outside of the arrow folder that included the purple arrow texture.
 * The ruby item texture.
 * The piglin leather armor models.
 * The footprint particle.