Minecraft Java Edition 21w15a Snapshot Patch Notes: Full list of changes

Mojang recently made a huge announcement regarding the release of the upcoming Minecraft update. The Caves and Cliffs update is now split into two parts. The first part will be released in the summer, while the second part is planned for the holidays.

As a response to this announcement, Minecraft: Java Edition Snapshot 21w15a has been released with a series of changes for the Caves and Cliffs Update.

Since most of the world generation changes from the Caves and Cliffs Update will be released in the winter, Snapshot 21w15a has reverted many features to how they were in Minecraft 1.16.

For example, the world height level has been switched back to 0-256. There are no more caves below Y level 0.

Here is the full list of changes in Minecraft Snapshot 21w15a:

Minecraft Java 21w15a Snapshot

Caves & Cliffs World Generation

Snapshot 21w15a has reverted many features to how they were in Minecraft 1.16 (Image via Minecraft)

The riskier and technically more complex world generation changes for the Caves & Cliffs update will arrive this winter 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 Minecraft Caves & Cliffs Prototype Data Pack

The riskier and technically more complex world generation changes for the Caves & Cliffs update will arrive this winter (Image via Minecraft Wiki)

Players can still try out the world generation changes using a data pack that activates them as an experimental custom world. They can do so by following the steps given below:

Players can download the data pack here.
They can then launch the game, go to the “Create New World” screen and click the “Data Packs” button.
Next, players should drag the downloaded zip file onto the Minecraft window.
The game will ask players if they want to add the data pack. They should click on the “Yes” button.
Players can press 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.
They should then click the “Done” button and continue creating their world as normal.

New features in Minecraft Snapshot 21W15A

Goats will ram anything that moves (Image via Minecraft)

Changes in Minecraft Snapshot 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 won't dare mess with Goats.
The main menu background has been updated.
Tweaked the textures of raw ore items.
Just like other ore materials, players can craft a compact version with raw ore items in order to save inventory space.

Compact forms of raw and refined underground materials have been reordered (Image via Minecraft.net)

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 Minecraft Snapshot 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.

This Snapshot also has many bug fixes related to glow liches, deep slate blocks, copper ores, and more.

Check out the detailed bug fixes and technical changes on Minecraft's official website.