Java Edition 16w20a

16w20a is the first snapshot released for 1.10.

General

 * Sound events


 * Options
 * A new 'Auto-jump' toggle has been added, which automatically makes the player jump when running towards a one block tall obstacle.
 * It's turned on by default.


 * Loot tables
 * A new tag  for the   function.
 * It determines the maximum amount the player can expect to receive on mob drops when using the looting enchantment of any level.


 * Particles
 * A new  particle has been added.
 * Appears underneath gravity-affected blocks that generate suspended in midair, with the world generation.
 * It sometimes appears whenever a gravity-affected block is placed without a support block below.
 * Does not apply to dragon eggs.


 * NBT tags
 * : Determines the kind of zombie a specific zombie is.
 * 0: default, 1-5: villager, 6: husk.
 * This tag, in effect, unifies the characteristics of being a zombie, a specific zombie villager and a husk into a single variable.
 * Intended to replace the  and   tags.
 * These tags are kept for backwards compatibility, but no newly generated entities have them.


 * Debug screen
 * + toggles the visibility of chunk borders around the player.
 * Everytime it is toggled, a message in chat appears.
 * It shows a blue outline for the chunk the player is currently in and a yellow outline for individual air blocks in the vicinity of the chunk.
 * The blue outline in particular, will outline the chunk horizontally on top of the solid blocks on the ground.
 * The outlines extended arbitrarily up, but end at bedrock level.

World generation

 * Fossils
 * Generates 15–24 blocks underground in Desert, Swampland, Swampland and their variants. Each chunk has a $1/64$ chance of generating a fossil.
 * Composed of bone blocks and some coal ore, arranged as to resemble the skulls and spines of giant extinct creatures.
 * There are 4 variants of the skull, and 4 variants of the spine sections.

Blocks

 * Structure void
 * Used for the structure block to keep the blocks in that location.
 * Intended to be a replacement for the function barrier blocks used to convey, so they can form part of the structure itself.
 * They are invisible and have a small hitbox.
 * They are only visible when using the feature in (save) structure blocks.


 * Magma block
 * Found in the Nether, generating 4 veins per chunk between Y=27 and Y=36.
 * It has a similar frequency to blocks like andesite in the Overworld.
 * Crafted using four magma cream.
 * Mobs and players take half a heart of damage every second while touching it, similar to a cactus.
 * Unlike cactus or fire, this block doesn't destroy items that touch it.
 * If the player is sneaking, wearing Frost Walker-enchanted armor, or under the effect, it does not take damage.
 * If the player dies by standing on it, a new death message will appear: "[Player] discovered that floor was lava."
 * If the player dies by the block, but after being damaged by a mob or player, the death message will be: "[Player] walked into danger zone due to [Mob or Player]."
 * Removes water blocks on top when randomly ticked.
 * It produces smoke particles under the rain.
 * It emits as much light as it receives from other sources.
 * e.g. A magma block next to a torch will emit light at level 13, as that was the light level it received from the torch.
 * If the torch were to be removed then it will search for the next brightest source of light; if no source is found then it will not produce light.


 * Nether wart block
 * Crafted by filling a 3x3 square in the crafting table with nether wart.
 * It cannot be crafted back into nether wart.
 * It destroys itself almost instantly in contact with water or lava.
 * It is better mined with an axe.


 * Red nether brick
 * Crafted by placing a 2x2 checkerboard of 2 nether brick and 2 nether wart in a crafting table.


 * Bone block
 * Crafted by filling a 3x3 square in the crafting table with Bone Meal.
 * Placing it in a crafting table yields 9 bone meal back.
 * Found underground in desert and swamps as part of the fossil structure

Items

 * Spawn eggs
 * Now exists for:
 * Wither skeleton.
 * Mule.
 * Skeleton horse.
 * Zombie horse.
 * Donkey.
 * Cat.
 * Elder guardian.
 * Stray (new variant): Dark grey with light gray dots.
 * Husk (new variant): Brown with cream colored dots.
 * Polar bear (new mob): White with grey dots.

Mobs

 * Polar bear
 * Adults and children spawn randomly as passive mobs in Ice Plains, Ice Mountains, and Ice Plains Spikes.
 * When hit, the adults will attack you, the cubs will run away (very fast, similar to baby zombies).
 * Additionally, adults will always attack you when their cubs are around
 * Adults can swim faster in water than the player.
 * Drops 0–2 raw fish (75% chance) or 0–2 salmon (25% chance), each increased by 1 per level of Looting.


 * Stray
 * 80% of skeletons spawned above ground in Ice Plains, Ice Mountains, and Ice Plains Spikes biomes will be strays.
 * All spawns where the skeleton does not have a view of the sky will be normal skeletons.
 * Spiders spawned in cold biomes have a chance of having a stray riding it.
 * Acts mostly like a regular skeleton.
 * Its  tag is 2.
 * Drops are the same as skeletons, but also have a 50% chance to drop 0-1 tipped arrow of when killed by the player. With looting, chance increases to $2×level+1/2×level+2$.
 * Shoots Tipped Arrows of Slowness (0:30) at the target.


 * Husk
 * 80% of zombies spawned above ground in Desert, Desert Hills, and Desert M biomes will be husks.
 * All spawns where the zombie does not have a view of the sky will be normal zombies or zombie villagers.
 * Behaves mostly like a regular zombie
 * Its  tag is 6.
 * Does not burn in sunlight.
 * Can spawn as a baby or as a chicken jockey.
 * Applies 7 seconds of hunger when attacking in Easy, 14 in Normal and 21 in Hard difficulty.
 * Visually 2 pixels taller than zombies, but has the same hitbox.

General

 * NBT tags
 * now works for all entities, not only armor stands.
 * A mob in midair affected by it, will still respond to knockback by moving horizontally.
 * Although the AI will not permit any mob to move on their own, horses and pigs ridden by the player, will move normally.
 * Very similarly, boats in the air ridden by the player, will move as if they were in water.


 * Huge mushrooms
 * Huge mushrooms have a 1⁄12 chance of generating twice as tall as normal.
 * These new mushrooms can appear during world generation or by being planted by the player.

World generation

 * Plains and Sunflower Plains
 * Now have some trees in 5% of its chunks ($1/3$ large oaks, $2/3$ normal oaks).


 * Ice Plains, Ice Mountains, and Ice Plains Spikes
 * Have a lower chance of spawning passive mobs during world generation than other biomes (7% versus 10%).


 * Mesas, including all variants
 * Hardened clay and stained clay no longer generate more than 15 blocks deep, if the mesa is more than 15 blocks above sea level.
 * In addition to the normal 2 veins of gold ore below Y=32, attempts to generate 20 veins between Y=32 and Y=79.
 * Generate the new type of abandoned mineshafts, described below.


 * Abandoned mineshafts
 * New mineshaft type that generates in mesa biomes (including all variants).
 * Placed so that the midpoint of the structure is near sea level, rather than so that the top is 10 blocks or more below sea level.
 * Uses dark oak wood for wooden structures.
 * New NBT tag  on mineshaft structure pieces to indicate the type. 0 is the traditional mineshaft, 1 is the new mesa mineshaft.
 * Features generate differently if above ground (i.e. the sky light where they generate is 8 or more). This is not dependent on mineshaft type.
 * Cave spider spawners no longer generate if sky light is 8 or more.
 * Various wooden pieces no longer generate if the block above is air and/or if sky light is 8 or more.
 * Rails in corridors are more complete if sky light is below 8.
 * 90%, versus 70% in 1.9 and in above-ground corridors.


 * Villages
 * Village structures are no longer restricted by biome boundaries.
 * Meaning that a village that starts in a valid biome can now spread into an adjacent invalid biome.
 * Now generate in taigas (but not variants).
 * They are made with spruce wood.
 * Savanna villages are now made with acacia wood instead of oak.
 * In savannas, acacia logs replace cobblestone in all structures except churches
 * Paths no longer generate below sea level, and in non-desert villages they are made with different material depending on the existing terrain.
 * If replacing grass blocks, the path is made from grass path blocks.
 * If replacing water or lava, the path is made from planks.
 * Otherwise, the path is gravel on top of cobblestone (including bridges across ravines).
 * Sandstone paths still always generate in desert villages
 * They have a 2% chance of being a zombie village.
 * All generated villagers are instead zombie villagers.
 * There are no doors or torches in the village.


 * Caves
 * No longer turn adjacent sand blocks in the ceiling into sandstone when generating.

Blocks

 * Structure block
 * The intended purpose is revealed.
 * It is to allow the player to save and load different created structures in game, and offer a way to bundle such structures with the world.
 * The block still has four modes, but each has a completely different texture than the original.
 * D, data - for chest markers and other blocks that require data (default)
 * S, save - build structure in world, tell the block where it is and it saves it to file
 * L, load - loads saved structure files, replacing blocks with saved blocks except for structure void blocks.
 * C, corner - for automatic size calculation
 * Are now available in item form; can be given or summoned.
 * Similarly to command blocks, its placement, destruction and modification are restricted to opped players in creative.
 * Now comes with an integrated GUI.
 * Structures can be stored, bundled and loaded per world, in the "structures" folder
 * Structures are limited to a size of 32 blocks in each direction.
 * The coordinates used by the blocks are relative to themselves.
 * When in use, it shows the outline of the structure it relates to in white
 * Can rotate and mirror structures before they are placed.
 * L and S structure blocks can be activated by redstone.
 * The game protects against maps saving arbitrary amounts of data to disk.
 * Red and blue small little cubes can be displayed in the selection area.
 * Blue is for air blocks, red is for structure void blocks.
 * Display a name tag above them indicating their mode and structure name.


 * End stone bricks
 * Are no longer craftable.

Items

 * Firework rocket
 * Recipe now produces three rockets rather than only one.

Mobs

 * Endermen
 * Can now rarely spawn in the Nether with a $1/153$ rate.
 * Compared to $100/153$ for zombie pigmen.
 * Can now naturally pick up netherrack


 * Magma cubes
 * Spawn about twice as often in the Nether.
 * The rate is now $2/153$, compared to $1/151$ before

Fixes

 * More fixes:
 * Fixed some broken uses of relative coordinates