Java Edition 17w13a

17w13a is the second snapshot released for Java Edition 1.12.

Items

 * Knowledge books
 * A green-colored book.
 * Currently obtainable only with the command.
 * A Knowledge Book with a  NBT tag, which contains a list of item IDs, will be consumed and unlock the specified items' recipes for any player that  it.
 * Especially useful when is set to true.


 * Spawn eggs
 * Parrot (new mob): Green with red dots.

Mobs

 * Parrots
 * Tamable with cookies
 * Fly around, but sit when "tired."
 * Follow and crowd around nearby mobs.
 * Imitates sounds of other mobs.
 * tamed parrots will place them on the player's shoulder.
 * Will let go if the player jumps.
 * Can fly with players during elytra flight.
 * Have health.
 * Come in red, blue, green and cyan.

Gameplay

 * Gamerules
 * Off by default.
 * Enabling will only allow players to craft recipes they have unlocked.
 * Enabling will only allow players to craft recipes they have unlocked.

Command format

 * Can unlock, or lock, the given recipes for the given player.
 * If  is specified, it will lock or unlock all recipes for the player.
 * Can grant, test or revoke advancements, and particular advancement criteria, for a given player.

General

 * Advancements
 * Replaces achievements.
 * Can be customized via JSON files.
 * Tab-based UI.
 * Currently one tab (Minecraft) although more will be supported in the future.
 * Different background per tab, single texture on repeat for now.
 * Data-driven UI, including positioning and layout.


 * Narrator
 * + toggles a text-to-speech engine that automatically reads player chat messages, including the name.
 * The Narrator will not read commands or command outputs, nor will it read messages produced with.


 * NBT tags
 * / : Contains entity data about an entity on the left and right shoulders of the player.
 * : Changes to 1 if the player leaves the End through the portal.
 * : A string containing a list of recipes, formatted as JSON, that the player has seen.
 * : A list of crafting recipes to unlock for the player that right-clicks while holding a Knowledge Book.
 * If this is not specified, the Knowledge Book will not be consumed.


 * Recipe books
 * Catalogs recipes that are unlocked when the criteria are met.
 * When a recipe is clicked, it will appear in the crafting grid, and can be crafted if materials are available.
 * folder added with all item recipes as  files.

Blocks



 * Glazed Terracotta
 * Textured changed for cyan, magenta, orange, and white glazed terracotta, to remove unintentional and potentially offensive imagery.


 * Beacons
 * Now display their name when hovering over them.


 * Enchantment Tables
 * Now display their name when hovering over them.

Items

 * Fishing rods
 * Changed the sound of bobbers being thrown.

General

 * Achievements
 * Removed and replaced by advancements.


 * Crafting
 * Closing the crafting interface with items inside will no longer drop the items in front of you, but will send them instead to the inventory.


 * Java version
 * This is the first snapshot to use, and thus require, Java 8.


 * Moving backwards
 * The player's body now entirely faces to the front, when moving backwards.
 * Prior to this snapshot, moving backwards would cause the player model to rotate one side, making it look like the player was strafing backwards somewhat.

Video
Video made by slicedlime:

Trivia

 * 17w13a was previously removed from the launcher for some time, but was added back in September 2018.