{ "format_version": "1.13.0", "minecraft:feature_rules": { "description": { "identifier": "minecraft:swamp_surface_mushrooms_feature", "places_feature": "minecraft:legacy:small_mushrooms_feature" }, "conditions": { "placement_pass": "surface_pass", "minecraft:biome_filter": [ { "test": "has_biome_tag", "operator": "==", "value": "swamp" } ] }, "distribution": { "iterations": 8, "x": 0, "y": 0, "z": 0 } } }