Customise World Creation

Creating worlds with a namespaced key

By default, world names are plain strings such as survival or my_world. Starting in v5.7, you can also supply a namespaced key (in the format namespace:key) as the world name, which gives the world a stable identifier that is independent of its folder name. By default, the namespace is minecraft, so the old plain names are still supported as keys under the minecraft namespace (e.g. minecraft:survival).

/mv create myplugin:pvp_arena normal

Any string containing a : is treated as a namespaced key. The namespace and key both follow Minecraft's identifier rules (lowercase letters, digits, _, -, .).

Where is the world folder, and what's the world name?

The folder location depends on your server software and version:

Paper 26.1+ — All worlds are stored under <level-name>/dimensions/<namespace>/<key>/.
For example, myplugin:pvp_arena on a server with level-name=world lives at:

world/dimensions/myplugin/pvp_arena/

The vanilla dimensions follow the same layout:

As for world names, those with default namespaces (i.e., starting with minecraft:) will retain only the second half of the key as the world name, just like before. The default worlds will also still be named <world>, <world>_nether and <world>_the_end as well (following your level-name). To ensure custom namespace key worlds will not produce duplicated world names, Paper has opted for those to be formatted by replacing : with _ instead. For example, myplugin:pvp_arena will have myplugin_pvp_arena as the world name. This will allow you to have the pvp_arena key with 2 different namespaces.

Spigot / older Paper — Worlds are stored as folders in the server root directory. The namespace is ignored entirely; only the key portion (the part after the :) is used as the folder and world name: | Namespaced key | Folder | World Name | |---|---| | myplugin:pvp_arena | pvp_arena/ | pvp_arena | | minecraft:overworld | world/ | world | | minecraft:the_nether | world_nether/ | world_nether | | minecraft:the_end | world_the_end/ | world_the_end |

You can look up a world's key and name with /mv info or via the %multiverse-core_key%/%multiverse-core_name% placeholder.

Creating a flat/superflat world

The command to create a very basic flat world: /mv create <world-name> normal --world-type flat

Customizing superflat world

You can customize the layers and biome of your superflat world using the --generator-settings flag. The value for this flag is a JSON string that defines the layers and biome. For example, to create a flat world with a layer of stone, a layer of grass, and a layer of sea lanterns, you can use the following command:

/mv create flat normal --world-type flat --generator-settings {"layers":[{"block":"stone","height":1},{"block":"grass_block","height":1},{"block":"sea_lantern","height":1}],"biome":"plains"}

Creating a void world

Void worlds are worlds that are completely empty, with no blocks or terrain (except for a single spawnpoint). There are two main methods to create a void world in Minecraft.

Method 1: Using flat world with THE_VOID biome

By using the --generator-settings flag introduced about, you can create a flat world with the the_void biome. This will create a world that is completely empty, except for 33x33 stone platform. You can use the following command to create a void world:

/mv create thevoid normal --world-type flat --generator-settings {"layers":[{"block":"air","height":1}],"biome":"the_void","features":true}

Method 2: Using void generator plugin

Firstly, install this VoiGen generator plugin: https://www.spigotmc.org/resources/fork-of-voidgen-1-21-3-supported.121721/

Creating a void world is as shown below. See https://github.com/NicoNekoDev/VoidGen/wiki/Parameters for more customization options of the void world.

/mv create <worldname> normal --generator VoidGen --world-type flat

If you are importing a world and want to continue it being void in new chunks:

/mv import <worldname> normal --generator VoidGen --world-type flat

Single biome worlds

You can create a world with a single biome using the --biome flag. For example, to create a normal world with only the desert biome, you can use the following command:

/mv import <worldname> normal --biome @single:desert

All the biomes can be found here: https://hub.spigotmc.org/javadocs/bukkit/org/bukkit/block/Biome.html (note that some biomes may not be available in certain Minecraft versions)