How to Control Which Structures Spawn in Ruins Mod

Find the Config Files

Ruins reads its spawn rules from configuration files in your Minecraft config directory. Look for files that list each structure alongside its biome, dimension, and rarity settings. Open them in a plain text editor so you can read the comments explaining each field.

Disable or Restrict Structures

To stop a structure from spawning, either remove its entry or set its rarity to a value that prevents selection. To limit it to certain biomes, edit the biome list to include only the biomes you want. You can also restrict structures to specific dimensions, so a sky castle only appears in the Overworld while a nether-themed ruin stays in the Nether.

Tune Rarity and Density

Rarity controls how often a structure is chosen relative to others. Raising the number makes it rarer; lowering it makes it more common. If your world feels too crowded, raise rarity across the board or reduce the total number of spawn attempts in the global settings. After editing, save the files and start a new world, since spawn rules apply at world generation and won't retroactively change existing chunks.