In today’s snapshot, we’re making a few needed changes that directly relate to our recent announcement. If you haven’t yet read it, we strongly recommend you do. You can also check out this Caves & Cliffs video from Agnes and Henrik to learn more about our plans for the update.

Even though some features will be released later than we’d planned, you can still try them out through a separate data pack. More information, as well as our latest tweaks, can be found here below.

Caves & Cliffs World Generation

The riskier and technically more complex world generation changes for the Caves & Cliffs update will be shipped in a later update and have been switched off in this snapshot. This means:

World height has been switched back to the 1.16 levels
Noise caves and aquifers have been switched off
Cave and ravine carvers have been returned to their old settings
Crack carvers have been switched off
Ore distribution has been returned to the 1.16 setup
Copper now generates between the bottom of the world and height 192, being most common around height 96
Tuff now generates in blobs between heights 0 and 16
Worlds created in snapshot 21w05b or any earlier version can now once again be opened
Worlds created in any version between snapshot 21w06a and 21w14a can no longer be opened

The Caves & Cliffs Prototype Data Pack

You can still try out the world generation for the later update using a datapack which activates the changes as an experimental custom world:

Download the data pack
Launch the game, go to the "Create New World" screen, and click the “Data Packs” button
Drag the downloaded zip file onto the Minecraft window
The game will ask you if you want to add the data pack – click “Yes”
Click the play arrow on the data pack that just appeared in the list – this will move it to the list on the right-hand side of the screen
Click the "Done" button and continue creating your world as normal

Keep in mind that the world you create with the data pack will be flagged as experimental by the game, and such worlds are not guaranteed to work in future versions. Also, please note that you can’t add data packs that change the world generation to existing worlds, so you must create a new world to access the experimental features.

New Features in 21w15a

Goats will ram anything that moves... and also armor stands

Changes in 21w15a

A crinkly, crunchy sound now plays when Bone Meal is used
Reordered some blocks in the Building Blocks Tab in Creative Menu
Goats will avoid walking on powder snow
Creepers know not to mess with goats
The main menu background has been updated
Tweaked the textures of raw ore items
Just like other ore materials, you can craft a compact version with raw ore items in order to save inventory space

Minecraft Snapshot 21w15a Texture Comparison New raw ore textures in snapshot 21w15a. Click here for a link to the full resolution image.

Building Blocks tab

All ores have been reordered to be in the same location in the creative inventory.
Compact forms of raw and refined underground materials have been reordered.

Technical Changes in 21w15a

Added the Marker entity
Added /debug function
selector and nbt chat components can now configure separators between elements
Servers can now customize a message to display when prompting players about custom resource packs

Markers

Markers are a new type of entity meant for custom use cases like map making and data packs.

Only exist on the server side, are never sent to clients
Do not do any updates of their own
Have a data compound field that can contain any data

`/debug function`

New debug subcommand executes command with same syntax as function

Every executed command, message (even if it would be normally invisible), result or error is stored to file
Cannot be run from inside functions

Chat component separators

Components that print lists of names, like selector or nbt can now override separator (", " by default) with separator element
Examples:
- {"selector": "@e[type=chicken]", "separator": "|"}
- {"nbt": "CustomName", "entity": "@e[type=chicken]", "interpret": true, "separator": {"text": "*", "color": "red"}}

Custom server resource packs

When require-resource-pack is used in server.properties, there's now an option for servers to add a custom message.

A dedicated server can configure additional message to be shown on resource pack prompt (resource-pack-prompt in server.properties, expects chat component syntax, can contain multiple lines)

Bugs fixed in 21w15a

MC-203855 A geode configured_feature causes a crash when use_alternate_layer0_chance is used with no entries in inner_placements
MC-212145 Summoning Glow Lichen using /setblock doesn't place any lichen but creates light until the block is updated
MC-212273 Glow Lichen doesn't render when being held by an Enderman
MC-215836 Deepslate uses the same color as stone on maps
MC-215844 Stone still generates around lava pools at low levels
MC-216588 Feature placement - java.lang.IllegalArgumentException: bound must be positive
MC-218588 Cracked deepslate bricks & tiles are in the incorrect position in the creative inventory
MC-218698 Infested deepslate makes the old "stone" sounds
MC-218705 Deepslate emerald ore is separated from other deepslate ores in the creative inventory
MC-218749 Deepslate coal ore doesn't drop experience
MC-218944 Copper ore and deepslate copper ore have inconsistent textures
MC-219972 Deepslate gold ore has an inconsistent pixel
MC-221501 Water splash potions don't give the axolotl 1.5 minutes of moisture
MC-221718 Lava fog repeatedly fails to render each block at certain y-levels
MC-221798 Blindness doesn't render correctly
MC-222104 Beacon beam fog is incorrectly computed
MC-222266 Goats don't attack
MC-222522 Nether Gold Ore is no longer smeltable