Biome/Before 1.18

In Java Edition 1.18 and Bedrock Edition 1.18.0, Overworld terrain generation was rewritten to be more varied and independent of biome generation. This made many biome variants that were in the game redundant, as the only difference between them and their regular counterparts was the way terrain generated in them. As a result, most variant biomes were removed from the generator. In Java Edition, these biomes were merged with their normal variants, while in Bedrock Edition, these biomes still exist but are no longer used.

Minecraft biomes were generated in layer stacks. These layers generated specific aspects of Minecraft biomes, such as scale, rivers, varieties, and biome categories.

Biome generation was initialized as a 1 to 4096 scale of ocean, with a few spots of landmasses scattered throughout. This map was then scaled and additional landmasses shuffled around to decrease the amount of ocean, twice, to reach a scale of 1 to 1024. Additional layers that decrease the amount of ocean were repeatedly applied until the ratio of land to ocean was about 50-50. Snowy biome categories were then assigned to a few spots of land, which was then shuffled around a final time to obtain a ratio of 33% ocean and 67% landmass.