{ "format_version": "1.13.0", "minecraft:feature_rules": { "description": { "identifier": "minecraft:river_surface_seagrass_feature", "places_feature": "minecraft:seagrass_feature" }, "conditions": { "placement_pass": "surface_pass", "minecraft:biome_filter": [ { "test": "has_biome_tag", "operator": "==", "value": "river" } ] }, "distribution": { "iterations": 12, "x": { "distribution": "uniform", "extent": [ 0, 16 ] }, "y": 54, "z": { "distribution": "uniform", "extent": [ 0, 16 ] } } } }