Minecraft Configured Feature

Configured Feature

Configured features (often just "features") are the basic units of world generation. Java Edition only. Note: this page was flagged on the wiki for needing updates for 26.2/26.3 registry renames.

Definition Format

• Before Java 26.3: registry CONFIGURED_FEATURE, data pack path worldgen/configured_feature (files in data/<namespace>/worldgen/configured_feature; tags in data/<namespace>/tags/worldgen/configured_feature).
• From Java 26.3: registry FEATURE, data pack path worldgen/feature (files in data/<namespace>/worldgen/feature; tags in data/<namespace>/tags/worldgen/feature).

File format:

{
  "type": "<namespace id>",
  "config": { ... }
}

• type (required) — the feature type (namespace ID).
• config (required) — per-type configuration; some types use an empty object {}.

Behavior

Configured features are loaded once at server startup; /reload does not reload them — the server must be restarted. A configured feature pairs a feature type with config data; some types are fully defined by themselves (config: {}), others need detailed config.

Feature Types

Each entry: purpose + config fields (see the Minecraft Wiki "Configured feature" page or worldgen/feature/ JSON files in the source for full details; shared field types: block state, block state provider, int/float provider, rule test, block test, and placed feature references by ID/tag/inline).

• bamboo — bamboo; needs #bamboo_plantable_on at the position. Config: probability (0–1, chance of podzol under bamboo).
• basalt_columns — basalt column forest. Config: height (int provider, 1–10), reach (int provider, 0–3).
• basalt_pillar — a basalt pillar downward from the position (position must be air with a block above). Config: {}.
• block_blob — a random 3×3×3 block blob; position must be 3+ blocks above the world bottom. Config: state (block state), can_place_on (block test, retried one block down until 3 above bottom).
• block_column — a column of layered blocks. Config: allowed_placement (block test), direction (up/down/north/south/west/east), layers (list of {height: int provider ≥0, provider: block state provider, prioritize_tip: bool}).
• block_pile — a pile of blocks; position must be 5+ blocks above world bottom. Config: state_provider.
• blue_ice — a blue ice pile; position ≤ sea level −1, water at position or below, floating ice within 5 directions. Config: {}.
• bonus_chest — a bonus chest. Config: {}.
• chorus_plant — chorus plant; needs End stone below. Config: {}.
• coral_claw / coral_mushroom / coral_tree — claw/mushroom/tree coral reef; position must be in water. Config: {}.
• delta_feature — a delta (e.g. lava deltas); position not the delta body block, air above, other five directions not air. Config: contents (body block state), rim (edge block state), rim_size (int provider 0–16), size (int provider 0–16).
• desert_well — a desert well; needs sand below. Config: {}.
• disk — a disk (e.g. clay/gravel). Config: half_height (0–4), radius (int provider 0–8), rules (list of {if_true: block test, then: block state provider}), state_provider, target (block test).
• dripstone_cluster — dripstone clusters. Config: floor_to_ceiling_search_range (1–512), height (int provider 1–128), radius (int provider 1–128), max_stalagmite_stalactite_height_diff (1–64), height_deviation (1–64), dripstone_block_layer_thickness (int provider 0–128), density (float provider 0–2), wetness (float provider 0–2), chance_of_dripstone_column_at_max_distance_from_center (0–1), max_distance_from_edge_affecting_chance_of_dripstone_column (1–64), max_distance_from_center_affecting_height_bias (1–64).
• end_gateway — an end gateway. Config: exact (precise teleport), exit ([x, y, z] destination).
• end_island — an End island. Config: {}.
• end_platform — the obsidian platform. Config: {}.
• end_spike — obsidian spikes. Config: crystal_invulnerable (default false), spikes (list of {centerX, centerZ, radius, height (defaults 0), guarded (iron bars), crystal_beam_target ([x,y,z])}).
• fallen_tree — a fallen tree. Config: trunk_provider, log_length (int provider 0–16), stump_decorators, log_decorators (tree decorator lists).
• fill_layer — fills 16×1×16. Config: height (0–4032), state.
• fossil — fossil from structure templates. Config: fossil_structures (template list, same length as overlay_structures), overlay_structures, fossil_processors (processor list ID or inline), overlay_processors, max_empty_corners_allowed (0–7).
• freeze_top_layer — places snow/ice and sets snowy grass at the MOTION_BLOCKING heightmap per temperature. Config: {}.
• geode — a geode. Config: blocks (block set: filling_provider, inner_layer_provider, alternate_inner_layer_provider, middle_layer_provider, outer_layer_provider), inner_placements (non-empty block state list), cannot_replace, invalid_blocks (air hardcoded invalid), layers (thickness: filling 1.7, inner_layer 2.2, middle_layer 3.2, outer_layer 4.2, 0.01–50), crack (generate_crack_chance 1.0, base_crack_size 2.0, crack_point_offset 2), use_potential_placements_chance (0.35), use_alternate_layer0_chance (0.0), placements_require_layer0_alternate (true), outer_wall_distance (int provider 1–20), plus distribution params (distribution type per placed feature).
• glowstone_blob — a glowstone blob; position must be netherrack, basalt, or blackstone. Config: {}.
• huge_brown_mushroom — a huge brown mushroom; position in #dirt/#mushroom_grow_block, clearance above. Config: cap_provider, stem_provider, foliage_radius (default 2), can_place_on.
• huge_fungus — a huge Nether fungus. Config: valid_base_block, stem_state, hat_state, decor_state, planted (default false — when false, highest Y must stay under the dimension's total terrain height and replaced blocks drop nothing), replaceable_blocks.
• huge_red_mushroom — a huge red mushroom; position in #dirt/#mushroom_grow_block. Config: same as huge_brown_mushroom.
• iceberg — an iceberg. Config: state.
• kelp — kelp; position must be water. Config: {}.
• lake — a lake. Config: fluid, barrier (block state providers), can_place_feature, can_replace_with_air_or_fluid, can_replace_with_barrier (block tests).
• large_dripstone — large dripstone columns. Config: replaceable_blocks, floor_to_ceiling_search_range (default 30), column_radius (int provider min/max, 1–60), height_scale (float provider 0–20), max_column_radius_to_cave_height_ratio (0–1), stalactite_bluntness / stalagmite_bluntness (float providers 0.1–10), wind_speed (float provider 0–2), min_radius_for_wind (0–100), min_bluntness_for_wind (0–5).
• monster_room — a dungeon; needs solid 9×9 areas below/above and 1–4 non-solid blocks on the 7×7/7×9/9×9 ring. Config: {}.
• multiface_growth — glow lichen / sculk vein growth. Config: block (default glow_lichen; only glow_lichen or sculk_vein), search_range (default 10), can_place_on_floor/can_place_on_ceiling/can_place_on_wall (default false), chance_of_spreading (0–0.5), can_be_placed_on (block ID/tag/list).
• nether_forest_vegetation — a vegetation pile; position in #nylium. Config: state_provider, spread_width (>0, width = 2×−1), spread_height (>0).
• netherrack_replace_blobs — replaces target blocks in a radius (moves down on failure). Config: target (block state, Properties ignored), state, radius (int provider 0–12).
• no_op — does nothing; used to override existing features. Config: {}.
• ore — a spherical ore blob. Config: targets (list of {target: rule test, state}), size (0–64), discard_chance_on_air_exposure (0–1).
• random_boolean_selector — places one of two features by random boolean. Config: feature_false, feature_true (placed features).
• random_selector — tries a weighted list in order; first success wins. Config: features (list of {chance: 0–1, feature}), default (placed feature).
• replace_single_block — replaces one block. Config: targets (list of {target: rule test, state}).
• root_system — a surface feature with underground roots. Config: feature (surface placed feature), allowed_tree_position (block test), root_state_provider, root_replaceable, hanging_root_state_provider, required_vertical_space_for_tree (1–64), allowed_vertical_water_for_tree (1–64), root_radius (1–64), root_column_max_height (1–256), root_placement_attempts (1–4096), hanging_root_radius (1–64), hanging_root_placement_attempts (1–256).
• scattered_ore — a scattered ore blob (like ore). Config: targets, size (0–64), discard_chance_on_air_exposure.
• sculk_patch — a sculk patch. Config: charge_count (1–32), amount_per_charge (1–500), spread_attempts (1–64), growth_rounds (1–8), spread_rounds (1–8), extra_rare_growths (int provider 1–64, sculk shriekers), catalyst_chance (0–1).
• seagrass — seagrass; position must be water. Config: probability (0–1, tall seagrass chance).
• sea_pickle — sea pickles. Config: count (int provider 0–256).
• sequence — places features in order; stops at the first failure. Config: features (placed feature ID/tag/list/inline).
• simple_block — places a single block. Config: to_place (block state provider), schedule_tick (default false — schedule 1 random tick).
• simple_random_selector — random selection from a list. Config: features (same formats as sequence).
• speleothem — pointed dripstone growth. Config: base_block, pointed_block, replaceable_blocks, chance_of_taller_generation (0.2), chance_of_directional_spread (0.7), chance_of_spread_radius2 (0.5), chance_of_spread_radius3 (0.5).
• speleothem_cluster — dripstone-like clusters (same fields as dripstone_cluster, named speleothem_block_layer_thickness, chance_of_speleothem_at_max_distance_from_center, max_distance_from_edge_affecting_chance_of_speleothem).
• spike — a spike. Config: state, can_place_on (block test), can_replace (block test; air always replaceable).
• spring_feature — a fluid spring. Config: state (Name fluid ID + Properties), requires_block_below (default true), rock_count (default 4), hole_count (default 4), valid_blocks (block ID/tag/list).
• template — a random structure template. Config: templates (list of {id: template ID, rotations: [none|clockwise_90|180|counterclockwise_90]}; rotations default random).
• tree — a tree. Config: ignore_vines (default false), trunk_provider, foliage_provider, below_trunk_provider (defaults to a rule-based dirt provider respecting #cannot_replace_below_tree_trunk; absent = no replacement), trunk_placer, foliage_placer, root_placer (absent = no roots), minimum_size (see below). See the tree placer/foliage placer/root placer/decorator details below.
• twisting_vines — twisting vines; position must be netherrack, nether wart block, or crimson nylium. Config: spread_width (>0), spread_height (>0), max_height (>0; height in [1, max_height×2]).
• underwater_magma — underwater magma blocks. Config: floor_search_range (0–512), placement_radius_around_floor (0–64), placement_probability_per_valid_position (0–1).
• vegetation_patch — a vegetation patch. Config: replaceable, ground_state (block state provider), vegetation_feature (placed feature), surface (floor/ceiling), xz_radius (int provider), depth (0–128), vertical_range (int provider 0–256), extra_bottom_block_chance (0–1), extra_edge_column_chance (0–1), vegetation_chance (0–1).
• vines — vines. Config: {}.
• void_start_platform — the void platform. Config: {}.
• waterlogged_vegetation_patch — like vegetation_patch; also waterlogs generated blocks (ground_state replaced by water on the top layer away from edges). Config: same fields as vegetation_patch.
• weeping_vines — weeping vines; position must be netherrack or nether wart block. Config: {}.

Tree Sub-formats

Trunk Placers

Common: base_height (0–32), height_rand_a (0–24), height_rand_b (0–24) — trunk base height = base + randA + randB (max 80). type one of: straight_trunk_placer, giant_trunk_placer (2×2), forking_trunk_placer, fancy_trunk_placer, mega_jungle_trunk_placer, dark_oak_trunk_placer, bending_trunk_placer (extra: bend_length int provider 0–24, min_height_for_leaves >0), upwards_branching_trunk_placer (extra: extra_branch_steps >0, extra_branch_length ≥0, place_branch_per_log_probability 0–1, can_grow_through).

Foliage Placers

Common: radius (int provider 0–16), offset (int provider 0–16 — top of foliage vs top of trunk). type one of: acacia_foliage_placer, dark_oak_foliage_placer, blob_foliage_placer (oak/birch; extra height 0–16), bush_foliage_placer (pyramid; extra height), fancy_foliage_placer (ball; extra height), jungle_foliage_placer (extra height), spruce_foliage_placer (extra trunk_height int provider 0–24), pine_foliage_placer (sparse spruce; extra height int provider 0–24), mega_pine_foliage_placer (extra crown_height int provider 0–24), random_spread_foliage_placer (extra foliage_height int provider 0–512, leaf_placement_attempts 0–256).

Root Placers

trunk_offset_y (int provider), root_provider, optional above_root_placement (above_root_provider, above_root_placement_chance 0–1). type currently only mangrove_root_placer with mangrove_root_placement: max_root_width (0–12), max_root_length (0–64), random_skew_chance (0–1), can_grow_through, muddy_roots_in (replaced blocks become muddy roots), muddy_roots_provider.

Tree Decorators

type one of: trunk_vine, leave_vine (extra probability), cocoa (extra probability), beehive (extra probability), alter_ground (extra provider), attached_to_leaves (extra block_provider, probability, exclusion_radius_xz, exclusion_radius_y, required_empty_blocks 0–16, directions non-empty), attached_to_logs (extra block_provider, probability, directions), creaking_heart (extra probability), pale_moss (extra probability, leaves_probability, ground_probability — places pale_moss_patch), place_on_ground (extra tries default 128, radius default 2, height default 1, block provider).

Minimum Size

• two_layers_feature_size: limit (default 1), lower_size (default 0), upper_size (default 1) — minimum space (2u+1)² above/below limit.
• three_layers_feature_size: limit (default 1), upper_limit (default 1), lower_size (default 0), middle_size (default 1), upper_size (default 1) — three tiers; with optional min_clipped_height (0–80) allowing trees that can't reach full height to still generate if they exceed that height.