Dimensions & dimension types

The two files behind every world: a dimension/ instance that pairs a generator with a dimension type, and the dimension_type/ file that defines that dimension's physics and behavior.

The dimension instance

A dimension instance ties a dimension type (physics/behavior) to a generator (how terrain and biomes are produced). Creating the file registers a new dimension reachable via /execute in <ns>:<id> as a teleport target. Vanilla overworld/nether/end can be overridden by shadowing their path.

data/<ns>/dimension/<id>.json — shape

{
  "type": "<dimension_type id or inline object>",
  "generator": { "type": "<noise|flat|debug>", ... }
}

Generators: noise, flat, debug

Generator: noise

The standard terrain generator.

Generator: flat (superflat)

Generator: debug

{ "type": "minecraft:debug" } — the flat grid of every blockstate; no other fields.

Biome sources

The biome_source object (inside a noise generator) decides which biome goes where.

multi_noise parameter points

Each entry in biomes[] is { "biome": <id>, "parameters": {...} }. The six climate parameters temperature, humidity, continentalness, erosion, weirdness each accept either a single float OR a two-element [min, max] range. depth and offset must be single constants (offset is 0–1.0 and shrinks the biome as it moves away from 0). All values are on a −1.0 … 1.0 scale. The generator picks the biome whose point is nearest in 6-D space.

One parameter point

{
  "biome": "minecraft:plains",
  "parameters": {
    "temperature":     [-0.45, -0.15],
    "humidity":        [-1, -0.35],
    "continentalness": [-0.11, 0.3],
    "erosion":         [-0.7799, -0.375],
    "weirdness":       [-1, -0.9333],
    "depth": 0,
    "offset": 0
  }
}

Complete dimension examples

data/example/dimension/my_dim.json — a custom noise dimension

{
  "type": "example:my_dim_type",
  "generator": {
    "type": "minecraft:noise",
    "settings": "minecraft:overworld",
    "biome_source": {
      "type": "minecraft:multi_noise",
      "preset": "minecraft:overworld"
    }
  }
}

data/example/dimension/flatland.json — a single-biome flat dimension

{
  "type": "minecraft:overworld",
  "generator": {
    "type": "minecraft:flat",
    "settings": {
      "biome": "minecraft:plains",
      "lakes": false,
      "features": false,
      "structure_overrides": ["minecraft:villages"],
      "layers": [
        { "block": "minecraft:bedrock",     "height": 1 },
        { "block": "minecraft:dirt",         "height": 2 },
        { "block": "minecraft:grass_block",  "height": 1 }
      ]
    }
  }
}

Dimension types

A dimension type defines the physics and behavior of any dimension that references it: light, height bounds, coordinate scale, spawning rules, portals/beds, ambient rendering. Vanilla ships overworld, overworld_caves, the_nether, and the_end. It lives at data/<ns>/dimension_type/<id>.json.

Dimension type fields

Vanilla dimension type examples

Grounded 1.21 values, extracted from github.com/misode/mcmeta @ tag 1.21-data-json, data/minecraft/dimension_type/.

data/minecraft/dimension_type/overworld.json

{
  "ambient_light": 0.0,
  "bed_works": true,
  "coordinate_scale": 1.0,
  "effects": "minecraft:overworld",
  "has_ceiling": false,
  "has_raids": true,
  "has_skylight": true,
  "height": 384,
  "infiniburn": "#minecraft:infiniburn_overworld",
  "logical_height": 384,
  "min_y": -64,
  "monster_spawn_block_light_limit": 0,
  "monster_spawn_light_level": {
    "type": "minecraft:uniform",
    "max_inclusive": 7,
    "min_inclusive": 0
  },
  "natural": true,
  "piglin_safe": false,
  "respawn_anchor_works": false,
  "ultrawarm": false
}

data/minecraft/dimension_type/the_nether.json

{
  "ambient_light": 0.1,
  "bed_works": false,
  "coordinate_scale": 8.0,
  "effects": "minecraft:the_nether",
  "fixed_time": 18000,
  "has_ceiling": true,
  "has_raids": false,
  "has_skylight": false,
  "height": 256,
  "infiniburn": "#minecraft:infiniburn_nether",
  "logical_height": 128,
  "min_y": 0,
  "monster_spawn_block_light_limit": 15,
  "monster_spawn_light_level": 7,
  "natural": false,
  "piglin_safe": true,
  "respawn_anchor_works": true,
  "ultrawarm": true
}

Tricks & workarounds

Sources

• Minecraft Wiki — Custom dimension
• Minecraft Wiki — Dimension type
• Minecraft Wiki — World generation
• Minecraft Wiki — Superflat
• datapack.wiki — Custom worldgen
• misode/mcmeta — vanilla dimension_type extract (tag 1.21-data-json)