Java Edition 12w18a

12w18a is the fourth snapshot released for Java Edition 1.3.1.

This snapshot is known for being the version to make singleplayer worlds run on a local server, resulting in the use of separate threads for rendering logic and world logic. This change resulted in a large number of broken features, several of which are yet to be fixed in the latest version, and on weak computers can result in server-lag in singleplayer.

Blocks

 * Wood
 * Wood logs now have their proper names (e.g. Oak Wood).


 * Wood planks
 * Wood planks now have their proper names (e.g. Spruce Wood Planks).


 * Stone bricks
 * Stone bricks now have their proper names (e.g. Mossy Stone Bricks).

Items

 * Books
 * Game no longer pauses when writing in a book. Whether this applies to book and quills is unknown.


 * Cocoa beans
 * Cocoa beans are now obtainable in jungle tree leaves.


 * Signs
 * Game no longer pauses when writing in a sign.


 * Tools
 * Wooden tools work in furnaces as one full furnace use.

Mobs

 * Villagers
 * Villagers spawned from spawning eggs will get a random profession.

Gameplay

 * Breaking
 * The 1⁄4 second (5 tick) delay between block breaking has been removed for players in survival. The player can now instantly mine a large amount of blocks in survival simply by holding if conditions are met.


 * Hardcore
 * Hardcore is now available in multiplayer.


 * Singleplayer
 * Separated server logic and client, therefore singleplayer is now a local server.

Command format

 * General
 * Game no longer pauses when entering a command or pausing the game.

General

 * Debug screen
 * Coordinates are now rounded to 5 digits.
 * "ws", "fs" and "g" (Walking speed, flying speed and ground; "g" is true if the player is touching the ground).


 * Language files
 * Updated language files.


 * Splashes
 * Splash "Mojang" screen now appears for 1 second instead of 3.


 * Texture packs
 * Support and auto-download for server texture packs.


 * Server jar
 * The server jar now accepts command-line arguments,  ,  ,  , and  .  The old   argument still works for backward compatibility.

General

 * Features broken by the internal server


 * Many features were broken or significantly changed due to the client-server split, many of which still remain absent from the game.


 * Distance effects
 * The particles from adding an eye of ender to an end portal frame block will no longer appear offset if performed at high distances from the world origin.
 * This is due to the fact that they simply did not appear at all from this snapshot onwards, which is
 * This bug resurfaced in Java Edition 19w14a when the aforementioned absent particles bug was fixed.

Fixes

 * 4 bugs fixed
 * Fixed being unable to switch tools of the same kind in your inventory.
 * Fixed water destroying non-solid blocks when breaking them from above.
 * Fixed picking a block in creative with a tool in your hand causing you to lose it.
 * Fixed Silk Touch giving you only one slab from double slabs.

Trivia

 * In this version, when loading a single player world, one needs to put into  manually to continue loading.