Java Edition 1.12-pre1

1.12-pre1 is the first pre-release for Java Edition 1.12.

Gameplay

 * Gamerule
 * Runs a function every tick through the server.
 * Runs a function every tick through the server.

Command format

 * Runs a function once through the entity or command block which ran the /function command.

General

 * Advancements
 * 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  field to advancement display info, defaults to false
 * Added new,  ,   advancements triggers
 * Added  to advancement rewards


 * Functions
 * Added new function system, which are plaintext files in
 * Functions are a list of commands, one line per command, with  or   comment support


 * NBT tags
 * Added the  NBT tag for players.

Changes

 * Advancements
 * Advancement trees are now centered in the UI
 * Items & entities in advancements have an extra  field (string NBT, like in commands)
 * Entities in advancements have an extra  and   field
 * Removed  from advancement rewards
 * Removed  advancement trigger


 * Recipe books
 * Optimized the recipe book

Video
Video made by slicedlime:

Trivia

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