# Biomes > Define Minecraft biomes with climate, colors, mob spawns, carvers and features using Kore's type-safe Kotlin DSL. Updated 2026-10-26. Canonical: https://kore.ayfri.com/docs/data-driven/worldgen/biomes A biome describes a region of the world: its climate, its colors and sounds, which mobs spawn there, which carvers dig through it and which features decorate it. It does not decide where it appears - that is the job of the [biome source](https://kore.ayfri.com/docs/data-driven/worldgen/dimensions.md) of a dimension. ```kotlin val myBiome = dp.biome("my_biome") { temperature = 0.8f downfall = 0.4f hasPrecipitation = true attributes { skyColor(0x78A7FF) fogColor(0xC0D8FF) } effects { waterColor = color(0x3F76E4) } } ``` References: [Biome](https://minecraft.wiki/w/Biome), [Biome definition](https://minecraft.wiki/w/Biome_definition), misode's [biome generator](https://misode.github.io/worldgen/biome/) ## Where Biomes Land In The World The vanilla Overworld places biomes in a 6-dimensional climate space. Each biome claims an interval on every axis, and the game picks the closest match for a position. These are the same six parameters a `multiNoise` biome source lists per entry: | Parameter | Controls | Vanilla range | |-------------------|-----------------------------------------------------|----------------------------------------------------------------------------------------------------------------------------------------------------------------------------------| | `temperature` | Snow and ice coverage, vegetation types | 5 bands: `-1.0..-0.45`, `-0.45..-0.15`, `-0.15..0.2`, `0.2..0.55`, `0.55..1.0` | | `humidity` | Vegetation density, arid to humid | 5 bands: `-1.0..-0.35`, `-0.35..-0.1`, `-0.1..0.1`, `0.1..0.3`, `0.3..1.0` | | `continentalness` | Ocean, beach or inland | Mushroom fields `-1.2..-1.05`, deep ocean `-1.05..-0.455`, ocean `-0.455..-0.19`, coast `-0.19..-0.11`, near inland `-0.11..0.03`, mid inland `0.03..0.3`, far inland `0.3..1.0` | | `erosion` | Flat versus mountainous terrain | 7 bands: `-1.0..-0.78`, `-0.78..-0.375`, `-0.375..-0.2225`, `-0.2225..0.05`, `0.05..0.45`, `0.45..0.55`, `0.55..1.0` | | `weirdness` | Biome variants, for example Jungle to Bamboo Jungle | `-1.0..1.0`, cut into slices at `±0.05`, `±0.2667`, `±0.4`, `±0.5667`, `±0.7667` and `±0.9333`. A slice entirely below `0.0` picks the standard biome, the others its variant | | `depth` | Surface versus cave biome | Surface biomes at `0.0` and `1.0`, cave biomes in `0.2..0.9`, `deep_dark` at `1.1` | The vanilla Overworld uses the built-in `overworld` multi-noise preset, so these bands are fixed in the game and not in a datapack file (bounds above are rounded to four decimals). In its table of standard middle-terrain biomes, `snowy_plains` sits at temperature `-1.0..-0.45` with humidity `-1.0..0.1`, `dark_forest` at temperature `-0.15..0.2` with humidity `0.3..1.0`, and `desert` at temperature `0.55..1.0` with every humidity. The `temperature` and `downfall` fields on the biome itself are a different thing: they drive in-world behavior such as snow instead of rain, water freezing, and cauldrons filling. ## Climate Fields | Field | Type | Default | Vanilla | Effect | |-----------------------|-----------|---------|------------------------------------------------------|--------------------------------------------------------------------| | `temperature` | `Float` | `0.8` | `plains` `0.8`, `snowy_plains` `0.0`, `desert` `2.0` | Below `0.15`, precipitation falls as snow and water freezes. | | `downfall` | `Float` | `0.4` | `plains` `0.4`, `snowy_plains` `0.5`, `desert` `0.0` | Wetness, driving foliage tinting and how fast fire spreads. | | `hasPrecipitation` | `Boolean` | `true` | `desert` `false` | Whether rain or snow falls at all. | | `temperatureModifier` | enum | none | `frozen_ocean` `FROZEN` | `FROZEN` applies the noise-based warm patches of the frozen ocean. | ## Colors And Atmosphere Two blocks share this job, and the split matters: - `attributes { }` covers everything the camera sees or hears - sky, fog, particles, music, ambient sounds - plus gameplay rules. It is the same system dimension types use, so a biome value simply overrides the dimension value. See [Environment Attributes](https://kore.ayfri.com/docs/data-driven/worldgen/environment-attributes.md). - `effects { }` covers the biome-local block and liquid tints, which are not attributes. ```kotlin attributes { skyColor(0x78A7FF) fogColor(0xC0D8FF, EnvironmentAttributeModifier.ADD) } effects { waterColor = color(0x3F76E4) // Defaults to the vanilla overworld blue. foliageColor = color(0x59AE30) dryFoliageColor = color(0xA0A04C) grassColor = color(0x79C05A) grassColorModifier = GrassColorModifier.SWAMP } ``` Colors serialize as decimal integers. `grassColorModifier` applies the vanilla `SWAMP` or `DARK_FOREST` post-processing on top of the computed grass color. Reference: [Biome definition - Effects](https://minecraft.wiki/w/Biome_definition#Effects) ## Mob Spawns Mob spawns are the `natural_mob_spawns` [environment attribute](https://kore.ayfri.com/docs/data-driven/worldgen/environment-attributes.md#natural-mob-spawns), set in the `attributes { }` block of the biome (or of a dimension type), as is the `creatureWorldGenSpawnProbability` of the initial creature spawn during world generation. `spawnsByCategory` declares what may spawn per mob category. Within a category, `weight` is a relative probability against the other entries, and `count` is the size of a spawned group, written by `minCount`/`maxCount` or set to any int provider. ```kotlin attributes { creatureWorldGenSpawnProbability(0.07f) naturalMobSpawns { spawnsByCategory { creature { spawner(EntityTypes.COW, weight = 6, minCount = 2, maxCount = 4) spawner(EntityTypes.SHEEP, weight = 8, minCount = 2, maxCount = 4) } monster { spawner(EntityTypes.SKELETON, weight = 80, minCount = 1, maxCount = 2) spawner(EntityTypes.ZOMBIE, weight = 80, minCount = 1, maxCount = 2) } } } } ``` Categories: `ambient`, `axolotls`, `creature`, `misc`, `monster`, `undergroundWaterCreature`, `waterAmbient`, `waterCreature`. `spawnCosts` caps density with an energy budget instead of a raw count. Each mob spends `charge` from a shared `energyBudget`, so a crowded area stops spawning before it becomes a mob farm. ```kotlin naturalMobSpawns { spawnCosts { spawnCost(EntityTypes.COW, energyBudget = 1.2f, charge = 0.1f) } } ``` References: [Mob spawning](https://minecraft.wiki/w/Biome_definition#Mob_spawning), [Spawn costs](https://minecraft.wiki/w/Biome_definition#Spawn_costs) ## Carvers `carvers` is a flat list of carver IDs, or a single carver tag. They run during the `carvers` step, after the terrain noise and before any feature. ```kotlin carvers(myCaveCarver, Carvers.CAVE) ``` See [Carvers](https://kore.ayfri.com/docs/data-driven/worldgen/carvers.md). ## Features `features` lists placed features per [decoration step](https://kore.ayfri.com/docs/data-driven/worldgen.md#decoration-steps). Every property is a plain list, and leaving one empty simply means nothing of yours generates at that step. ```kotlin features { fluidSprings = listOf(PlacedFeatures.SPRING_WATER) lakes = listOf(PlacedFeatures.LAKE_LAVA_UNDERGROUND) localModifications = listOf(PlacedFeatures.AMETHYST_GEODE) surfaceStructures = listOf(PlacedFeatures.DESERT_WELL) topLayerModification = listOf(PlacedFeatures.FREEZE_TOP_LAYER) undergroundDecoration = listOf(PlacedFeatures.GLOW_LICHEN) undergroundOres = listOf(orePlaced) undergroundStructures = listOf(PlacedFeatures.MONSTER_ROOM) vegetalDecoration = listOf(treePlaced, flowerPlaced) } ``` See [Features](https://kore.ayfri.com/docs/data-driven/worldgen/features.md). ## Complete Example ```kotlin fun DataPack.highlandsBiome(treePlaced: PlacedFeatureArgument, orePlaced: PlacedFeatureArgument) { val cave = carversBuilder.cave("highlands_cave") { probability = 0.08 y = uniformHeightProvider(absolute(32), absolute(128)) floorLevel(-0.2f) } biome("highlands") { temperature = 0.8f downfall = 0.3f hasPrecipitation = true attributes { fogColor(0xBFEFFF) skyColor(0x99D9FF) waterFogColor(0x0A2C4F) naturalMobSpawns { spawnsByCategory { creature { spawner(EntityTypes.COW, 6, 2, 4) spawner(EntityTypes.SHEEP, 8, 2, 4) } monster { spawner(EntityTypes.SKELETON, 80, 1, 2) } } spawnCosts { spawnCost(EntityTypes.COW, 1.2f, 0.1f) } } } effects { waterColor = color(0x34A7F0) } carvers(cave) features { undergroundOres = listOf(orePlaced) vegetalDecoration = listOf(treePlaced) } } } ``` ## See Also - [Carvers](https://kore.ayfri.com/docs/data-driven/worldgen/carvers.md) - the caves and canyons a biome runs - [Dimensions](https://kore.ayfri.com/docs/data-driven/worldgen/dimensions.md) - biome sources placing biomes in a world - [Environment Attributes](https://kore.ayfri.com/docs/data-driven/worldgen/environment-attributes.md) - the full attribute reference - [Features](https://kore.ayfri.com/docs/data-driven/worldgen/features.md) - the placed features a biome lists - [World Generation](https://kore.ayfri.com/docs/data-driven/worldgen.md) - overview of the worldgen system