Minecraft Wiki
Minecraft 1.12-pre1
Java Edition 1.12-pre1.png

Java Edition



Release date

May 10, 2017

Pre-release for



Client (.json)

Protocol version


Data version


1.12-pre1[1] is the first pre-release for Java Edition 1.12. Which adds four new advancements, optimizing the Recipe Book and fixes bugs.



  • gameLoopFunction <namespace:path/to/function/file>
    • Runs a function every tick through the server.

Command format[]

/function <namespace:path/to/function/file>


  • Added new advancements:
    • A Furious Cocktail - Have every potion effect applied at the same time
    • Postmortal - Use a Totem of Undying to cheat death
    • Subspace Bubble - Use the Nether to travel 7km in the Overworld
    • Uneasy Alliance - Rescue a Ghast from the Nether, bring it safely home to the Overworld... and then kill it
  • Added hidden field to advancement display info, defaults to false
  • Added new effects_changed, used_totem, nether_travel advancements triggers
  • Added function to advancement rewards
  • Added new function system, which are plaintext files in world/data/functions/namespace/file.txt
  • Functions are a list of commands, one line per command, with // or # comment support
NBT tags


  • Advancement trees are now centered in the UI
  • Items & entities in advancements have an extra NBT field (string NBT, like in commands)
  • Entities in advancements have an extra effects and location field
  • Removed commands from advancement rewards
  • Removed arbitrary_player_tick advancement trigger
Recipe books
  • Optimized the recipe book


34 issues fixed
From released versions before 1.12
  • MC-11240 – Ignited TNT can be set on fire by a Flame Bow.
  • MC-50166 – Game states that "The block couldn't be placed" when using /setblock to place air in a space occupied by a tile entity, despite working
  • MC-95367 – Tamed dog, cat or parrot in a minecart teleports to a player (not visually)
  • MC-100468 – Dogs, cats and parrots teleport to player despite being in a boat (yet not visually)
  • MC-111699 – Can't rename stacked items
  • MC-111744 – Anvil outputs only 1 item when renaming
From the 1.12 development versions
  • MC-113380 – Concrete powder won't turn into concrete when replacing water
  • MC-113434 – The color of white wool sheep is light gray
  • MC-114235 – Concrete powder texture is not randomly rotated
  • MC-114534 – Beacon beam is darker than it should be
  • MC-115070 – Issue with crafting table UI on non-16:9 instances
  • MC-115206 – Parrots stare at bats over 30 blocks away, through the ground
  • MC-115460 – Recipe advancements for yellow dye have reversed unlock conditions
  • MC-115813 – Old (non-dyed) beds are invisible
  • MC-116024 – Pre-17w15a beds become red if in-world but white in chests
  • MC-116459 – Parrots suffocate when getting in a bed with a solid block behind it
  • MC-116760 – @a selector doesn't work with the /recipe command in multiplayer
  • MC-116945 – Knowledge book gives recipe before removing itself from inventory causing unexpected advancement behavior
  • MC-116952 – Can't read CPU info and shows 'CPU: <unknown>' in the debug screen (F3)
  • MC-116957 – Advancement doesn't get revoked when /reload is quickly executed afterwards
  • MC-116963 – Changing dimension prints debug message in log
  • MC-116964 – Parrots sometimes run in circles instead of pathfinding normally.
  • MC-117001 – "Serious dedication" challenge is granted when breaking any tool
  • MC-117007 – milk_bucket can't trigger consume_item of advancements
  • MC-117008 – Vines under trapdoors block them
  • MC-117015 – Glass panes & iron bars no longer connect to glass
  • MC-117019 – Tripwire hooks break off of backs and sides of stairs upon receiving a block update
  • MC-117036 – 17w18b Crafting book glitch
  • MC-117063 – Snow layers on barriers
  • MC-117069 – Door in Recipe Book when hold click shows the trapdoor recipe
  • MC-117118 – Levers / buttons placed on the trapdoor are dropped if pressed
  • MC-117160 – Parrots follow and watch invisible mobs
  • MC-117161 – Parrots imitate silent mobs
  • MC-117167 – Error message for player advancement data containing only "null" calls advancements "achievement"


Video made by slicedlime:


  • 1.12-pre1 was previously removed from the launcher for some time, but was added back in September 2018.