Java Edition 21w13a

21w13a is the fifteenth snapshot for Java Edition 1.17, released on March 31, 2021, which adds goats and light blocks, as well as tweaks to caves and ore vein generation, and fixes many bugs.

Blocks

 * Light block
 * A new waterloggable source of light, originally from Bedrock Edition.
 * Behaves like air and it is visible only when the item is held, similar to barriers.
 * Unlike barriers, light blocks can only be targeted when holding the item.
 * Obtainable only with.
 * Right-clicking cycles its light level.

Mobs

 * Goats
 * Spawn in mountains.
 * Currently a place holder until the new mountains are added.
 * Do not drop anything.
 * Can jump up to 10 blocks high.
 * Can be tempted and bred using wheat.
 * A bucket can be used on them to get milk.
 * They have a 2% chance of spawning as a screaming goat, with different sounds.

General

 * Accessibility
 * Added an alternative solid black background color for the Mojang Studios loading screen, toggleable with the “Monochrome Logo” accessibility category in options.


 * Tags
 * Added the block tag.
 * Contains dirt, coarse dirt, podzol and rooted dirt.
 * Grass, tall grass, ferns, tall ferns, sweet berry bushes, saplings, flowers, azaleas, sugar cane, and dead bushes can be placed in blocks in this tag.
 * Pumpkins and melons can grow into blocks in this tag.
 * Added the block tag.
 * Contains snow, snow blocks and powder snow.
 * Blocks in this tag turn blocks with a snowy variant below them (like grass) into said snow variant.
 * Added the entity type tag.
 * Contains tropical fish, pufferfish, salmon, cod, squid and glow squid, which were the previous contents of the entity type tag.
 * Axolotls exhibit the cooldown-based "hunt" behavior towards entities in this tag.
 * Added the entity type tag.
 * Contains striders, blazes and magma cubes.
 * Entities in this tag take 5 times more damage from the freezing effect.
 * Added the entity type tag.
 * Contains strays, polar bears and snow golems.
 * Entities in this tag cannot be frozen.

Blocks

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


 * Flowering Azaleas and Flowering Azalea Leaves
 * Are now seen as small flowers by the game.
 * Bees can pollinate them and can remember their position.
 * Bees follow players holding these blocks and can be bred with them.
 * Suspicious stew can be crafted with these blocks, giving a suspicious stew that gives no status effect.
 * Saplings grown next to these blocks have a small chance to generate a tree with a bee nest.
 * These blocks cannot be fed to brown mooshrooms.


 * Lightning Rod
 * Bottom texture is now corrected.


 * Powder Snow
 * Powder snow's hardness was slightly increased, from 0.1 to 0.25.
 * Freeze time has decreased to 7 seconds and hurt frequency has decreased to 2 seconds.
 * Entities on fire now melt powder snow when colliding, extinguishing themselves in the process.
 * Increased vertical movement speed within powder snow (entities fall through powder snow faster).
 * Mobs now shake when they are fully frozen.
 * Mobs that are damaged by freezing can no longer spawn on powder snow.


 * Rooted Dirt
 * The top texture is now randomly rotated.
 * Shovels are now the correct tool for collecting.
 * Grass, ferns, flowers, dead bushes, saplings and bamboo can now be planted on rooted dirt.
 * Small Dripleaf can be planted as well, but only when underwater.
 * Can now be turned into dirt path blocks by any type of shovel.
 * Now placed near other dirt variants in the Creative tab.


 * Texture mappings
 * Crops (wheat, carrot, potato. beetroot and nether wart), Chain, Ladder, Vines, and Glow lichen
 * Backside textures are now mirrored.
 * Tripwire, Tripwire Hook's Tripwire, Big dripleaf
 * Underside texture is now mirrored.
 * Lantern
 * Backside texture of chains are now mirrored.
 * Azalea, Powder Snow
 * Inner side textures are now mirrored.
 * Stonecutter
 * Backside texture of the saw is now mirrored.
 * Sea pickles
 * Backside texture of the tentacles are now mirrored.
 * Small dripleaf
 * Backside texture of the leaves are now rotated correctly.

Items

 * Leather Boots
 * Now prevent fall damage when landing on powder snow, to match the behavior in Bedrock Edition.


 * Leather Horse Armor
 * Now protects horses from freeze damage.
 * Although horses are the only entities that can wear leather horse armor through gameplay, leather horse armor worn by other entities through commands will also be protected.


 * Suspicious Stew
 * Can now be eaten even if the player is at full hunger.

Mobs

 * Axolotl
 * Axolotls now spawn naturally in underground water sources.
 * Axolotls are now always hostile towards drowned, guardians and elder guardians.
 * Axolotls will now "hunt" squids, glow squids, tropical fish, cod, salmon, and pufferfish.
 * After killing one of these mobs, there is a two minute cooldown before they can hunt again.
 * They will prioritize targeting hostile mobs first before hunting.
 * Axolotls give Regeneration I and remove Mining Fatigue when a player kills a mob that is in combat with an axolotl.
 * Blue, cyan, gold and pink axolotls have had the textures of the outlines on their tails slightly changed.
 * Cyan, gold and pink axolotls have had the textures of the frills on their head slightly changed.
 * Axolotls now save their NBT tags (such as age, color and health) when stored in a water bucket.


 * Blaze, magma cube, and strider
 * Now take more damage from freezing.


 * 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.


 * Endermen
 * Can now pick up rooted dirt, flowering azaleas and flowering azalea leaves.


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


 * Husk, zombie, and zombie villager
 * Now drop baked potatoes instead of normal potatoes if on fire when killed or killed by a fire source.


 * Polar bear, snow golem, and stray
 * Are now immune to freezing.


 * 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.


 * Villagers
 * Mason villagers can now sell 4 dripstone blocks for an emerald.
 * Can now accept a filled cauldron as a valid workstation.


 * Wandering trader
 * Added the following trades to the wandering trader:
 * Will sell 2 pointed dripstones for an emerald.
 * Will sell 2 rooted dirt for an emerald.
 * Will sell 2 moss blocks for an emerald.

World generation

 * Caves
 * Made carvers less likely to be too flat to walk through.
 * Increased likelihood of huge caves (very large cheese caves).
 * Reduced likelihood of tall 1-block thin pillars.
 * Changes were made to make the cheese caves more varied in aspect and size.
 * Deepslate blobs can now be found between heights 0 and 16.
 * Dripstone clusters can now be found rarely in regular caves.


 * End Islands
 * Due to a change in the height of the end, end islands are significantly taller. This behavior is not intended.
 * As a result, end spikes and the ender dragon are buried within the main island. End cities may be missing upper sections, as they might collide with the world height limit.


 * Mineshafts
 * Increased the max length of wooden pillars and chains.
 * Glow berries can be found in mineshaft chest minecarts.


 * Ore
 * Copper ore now generates uniformly between levels 0 and 63 instead of generating with a normal curve from 0 to 96.
 * Larger diamond ore veins sometimes form.
 * It was intended for iron ore veins to be more common, however this is not the case.


 * Shipwrecks
 * Moss blocks can be found in supply chests.

Gameplay

 * Advancements
 * Goats and axolotls are now required for "Two by Two".
 * Axolotls have always been available for "The Parrots and the Bats" and goats can now be used as well, though no 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".


 * 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.


 * Spawning
 * Added a new mob cap category, underground water creature.
 * Used by axolotls and glow squids.
 * Have a cap of 5, are friendly, are not persistent, and despawn at 128 blocks or more from the player.


 * Subtitles
 * Subtitles for waxing, removing wax, and removing oxidation from a block of copper now display.
 * These were introduced in the previous snapshot, but not correctly implemented.

General

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


 * Materials
 * Removed the coral material.
 * Added the moss material.


 * 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 particles.

Video
Videos made by slicedlime: