Minecraft Wiki
Minecraft 16w20a
Java Edition 16w20a.png

Java Edition



Release date

May 18, 2016

Snapshot for



Client (.json)

Protocol version


Data version


16w20a is the first snapshot for Java Edition 1.10, released on May 18, 2016,[1] which adds bone, magma, and nether wart blocks; husks and strays as zombie and skeleton variants, respectively; polar bears; and fossils that spawn underground.



Bone blocks
Magma blocks
  • Found in the Nether, generating 4 blobs per chunk between y=27 and y=36.
  • Crafted using four magma cream.
  • Mobs and players take 1♥ 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 Fire Resistance 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 entity".
  • 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 blocks
  • Crafted by filling a 3×3 square in the crafting table with nether wart.
  • It is broken by flowing water or lava, like most plants are.
Red nether bricks
Structure voids
  • 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 void.
  • Allows for empty spaces in a structure.
    • Unlike air, it will not overwrite blocks where it is loaded.
    • Example: If the player loads a 2-block-high structure with air at the top and a structure void at the bottom into a 2-block-high area of stone, the top block will become air but the bottom will stay stone.


Spawn eggs
  • Added cat egg: Light brown with brown spots.
  • Added donkey egg: Dark brown with light brown spots.
  • Added elder guardian egg: Light yellow-white with purple spots.
  • Added husk (new zombie variant) egg: Brown with cream colored dots.
  • Added mule egg: Dark brown with black spots.
  • Added polar bear (new neutral mob) egg: White with gray dots.
  • Added skeleton horse egg: Brownish-green with light gray dots.
  • Added stray (new skeleton variant) egg: Dark gray with light gray dots.
  • Added wither skeleton egg: Black with dark gray spots.
  • Added zombie horse egg: Dark green with light green spots..


  • 80% of zombies spawned above ground in desert biomes, and their variants, 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 ZombieType 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.
Polar bears
  • Adults and cubs spawn randomly as passive mobs in ice plains, ice mountains, and ice plains spikes.
  • When hit, the adults will attack the player, the cubs will run away (very fast, similar to baby zombies).
    • Additionally, adults will always attack the player when their cubs are around.
  • Can swim faster in water than the player.
  • Cubs will follow their parents.
  • Drops 0–2 raw fish (75% chance) or 0–2 salmon (25% chance), each increased by 1 per level of Looting.
  • 80% of skeletons spawned above ground in ice plains biomes, and their variants, 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 SkeletonType tag is 2.
  • Drops are the same as skeletons, but also have a 50% chance to drop 0-1 tipped arrow of Slowness when killed by the player. With looting, chance increases to 2×level+12×level+2.
  • Shoots Tipped Arrows of Slowness (0:30) at the target.

World generation[]

  • Generates 15–24 blocks underground in deserts, swamplands, and their variants. Each chunk has a 164 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.

Command format[]

NBT tags
  • ZombieType: 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 IsVillager and VillagerProfession tags.
      • These tags are kept for backwards compatibility, but no newly generated entities have them.
Sound events
  • Added block.enchantment_table.use.
  • Added entity.polar_bear.ambient.
  • Added entity.polar_bear.baby_ambient.
  • Added entity.polar_bear.death.
  • Added entity.polar_bear.hurt.
  • Added entity.polar_bear.step.
  • Added entity.polar_bear.warning.


Debug screen
  • F3 + G toggles the visibility of chunk borders around the player.
    • 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 extends arbitrarily up, but ends at bedrock level.
Loot tables
  • A new tag limit for the looting_enchant function.
    • It determines the maximum amount of mob drops the player can expect to receive when using the looting enchantment of any level.
  • A new 'Auto-jump' toggle has been added, which automatically makes the player jump when running towards a one block tall obstacle.
    • Enabled by default, can be disabled in Options.
  • A new fallingdust particle has been added.
    • Appears underneath gravity-affected blocks that are generated or placed suspended in midair.
    • Does not apply to dragon eggs.



End stone bricks
  • Are no longer craftable.
Structure blocks
  • 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 and new textures.
  • Has four modes:
    • Save - build structure in world, tell the block where it is and it saves it to file.
    • Load - loads saved structure files, replacing blocks with saved blocks except for structure void blocks.
    • Corner - for automatic size calculation.
    • Data - for chest markers and other blocks that require data (default).
  • 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.
  • Small red and blue cubes can be displayed in the selection area.
  • Save and Load structure blocks can be activated by redstone.
  • The game protects against maps saving arbitrarily massive amounts of data to disk.
  • Display a name tag above them indicating their mode and structure name.
  • New NBT tags
    • powered: Whether or not the structure block is currently being powered with redstone.
    • showboundingbox: Whether or not the bounding box of the structure is being outlined.
    • showair: Whether or not air blocks are indicated within the structure.


Firework rockets
  • Recipe now produces three rockets rather than only one.


  • Can now rarely spawn in the Nether with a 1153 rate.
    • Compared to 100153 for zombie pigmen.
  • Can now naturally pick up netherrack.
Magma cubes
  • Spawn about twice as often in the Nether.
    • The rate is now 2153, compared to 1151 before.
  • The Zombie Generic Villager is removed, due to the new zombietype tag.

World generation[]

  • No longer turn adjacent sand blocks in the ceiling into sandstone when generating.
Ice plains and variants
  • Don't spawn any other passive mobs than rabbits and the new polar bears anymore.
  • Also have a lower chance of spawning passive mobs during world generation than other biomes (7% versus 10%).
Mesas, including all variants
  • Terracotta and the dyed forms of terracotta 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 blobs of gold ore below Y=32, attempts to generate 20 blobs between Y=32 and Y=79.
  • Generate the new type of mineshafts, described below.
  • 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 MST 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.
Plains and sunflower plains
  • Now have some trees in 5% of its chunks (13 large oaks, 23 normal oaks).
  • 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 log.
  • 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, determined by Zombie NBT tag in Village.dat.

Command format[]

NBT tags
  • NoGravity 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, which can be up to 13 blocks tall, can appear during world generation or by being planted by the player.


4 issues fixed
From released versions before 1.10
  • MC-44579 – Cannot summon green-robed villager, even though its zombie counterpart works.
  • MC-87739/setblock with signs missing Text tags kicks all players loading the sign.
  • MC-89848/playsound/sound engine pitch algorithm isn't working properly.
  • MC-98779 – Skeletons spawned with /summon or natural spawning algorithm are not in the correct height.
More fixes
  • Fixed some broken uses of relative coordinates.[1]


Video made by slicedlime:


  • 16w20a was previously removed from the launcher for some time, but was added back in September 2018.