structures takes a weighted list of different structures (see below), allowing structure variants (for example the vanilla Nether has a structure set with both the bastion and fortress).
placement specifies in which chunks to spawn the structure. The simplest option is random_spread where you can give the average distance in chunks ( spacing) and the minimum distance in chunks ( separation). The salt is then used together with the world seed to randomly place structures in a chunk grid.
Full JSON format
: Root object.
structures: (Required, but can be empty) The structures that may be placed. One configured structure feature shouldn't be included by two structure sets.
: A structure to be placed.
structure: structure (referenced by ID or inlined) — The structure to be placed.
weight: Determines the chance of it being chosen over others. Must be a positive integer.
placement: How the structures should be placed.
salt: A number that assists in randomization; see salt (cryptography). Must be a non-negative integer.
frequency: (Optional, default to 1.0) Probability to try to generate if other conditions below are met. Values between 0.0 to 1.0 (inclusive). Setting it to a number does not mean one structure is generated this often, only that the game attempts to generate one; biomes or terrain could lead to the structure not being generated.
frequency_reduction_method: (Optional, defaults to default) Provides a random number generator algorithm for frequency. One of default (the random number depends on the seed, position and salt), legacy_type_1 (the random number depends only on the seed and position, and randomness only occurs when the locations differ greatly), legacy_type_2 (same as default, but with fixed salt: 10387320) and legacy_type_3 (the random number depends only on seed and position).
exclusion_zone: Specifies that it cannot be placed near certain structures.
chunk_count: Value between 1 and 16 (inclusive).
other_set: A structure set ID.
locate_offset: (optional, defaults to [0,0,0]) The chunk coordinate offset given when using /locate structure.
: X. Value between -16 and 16 (inclusive).
: Y. Value between -16 and 16 (inclusive).
: Z. Value between -16 and 16 (inclusive).
type: One of minecraft:concentric_rings or minecraft:random_spread.
Additional fields depending on value of type, see Placement types.
The structure is the ID you will be able to reference in the /locate command. It contains the configuration on what to place in the world, in which biomes, as well as structure properties like mob spawns.
When creating custom structures, you should always set type to jigsaw. The biomes field is a biome tag controlling which biomes are allowed to spawn this structure in. The start_pool references a template pool (see below) which will define the actual structure layout. If you want to use jigsaws, make sure to increase the size value. It is the jigsaw depth limit and it has a maximum of 20.
start_pool: template pool (referenced by ID or inlined) — The template pool the structure starts from.
size: Value between 0 and 20 (inclusive) — The depth of jigsaw structures to generate.
start_height: If project_start_to_heightmap is unset, the structure will start at the value provided. Otherwise, the value acts as an offset from the heightmap.
Height provider
project_start_to_heightmap: (optional) The heightmap the start height should project to. Can be WORLD_SURFACE_WG, WORLD_SURFACE, OCEAN_FLOOR_WG, OCEAN_FLOOR, MOTION_BLOCKING, or MOTION_BLOCKING_NO_LEAVES.
start_jigsaw_name: (optional) The name of the jigsaw block the structure start attaches to.
max_distance_from_center: The maximum 3D Chebyshev distance from the jigsaw pieces to the structure start. Value between 1 and 128 (inclusive) when terrain_adaptation is "none", otherwise from 1 to 116 (inclusive).
use_expansion_hack: Only used in villages.
pool_aliases: (optional) used to rewire jigsaw pool connections by redirecting pool references on individual structure instances.
dimension_padding: (optional, defaults to 0). Padding on the top and bottom world limit. : shorthand to set the same value for bottom and top.
bottom: (optional, defaults to 0), non-negative. Amount of blocks at the bottom build limit that are excluded from the outer bounding box of the structure.
top: (optional, defaults to 0), non-negative. Amount of blocks at the top build limit that are excluded from the outer bounding box of the structure.
liquid_settings: (optional, defaults to apply_waterlogging). How blocks with waterlogged block state should generate when they overlap with existing water. apply_waterlogging: waterlog block placed inside water, ignore_waterlogging: keep the waterlogged block state as is.
The template pool defines how to build up your structure. The example in this tutorial does not use jigsaw, so this is quite straight forward: we want to place a single structure NBT file.
A single structure is selected from the elements list. You can add structure variants by adding multiple elements here. The location field references a structure NBT file
Full JSON format
The root tag
fallback: template pool (referenced by ID) — Used as fallback if structures in this pool can't generate.
elements: A list of elements to randomly select from.
: An element.
weight: How likely this element is to be chosen when using this pool. Value between 1 and 150 (inclusive).
element: The properties of this element.
projection: Can be rigid to place a fixed structure (like a house), or terrain_matching to match the terrain height (like a village road).
element_type: Can be minecraft:empty_pool_element to generate nothing, minecraft:feature_pool_element to generate a placed feature, minecraft:list_pool_element to generate multiple elements one after another (lower elements replace their front ones), and minecraft:legacy_single_pool_element or minecraft:single_pool_element to generate a structure template. The difference between legacy_single_pool_element and single_pool_element, is that the legacy_single_pool_element does not replace existing blocks with air, and the single_pool_element replaces blocks with air and relies on the structure_void block to avoid not replacing blocks.
If element_type is feature_pool_element, additional fields are as follows:
feature: placed feature (referenced by ID or inlined) — The feature to place.
If element_type is list_pool_element, additional fields are as follows:
elements: A list of elements to choose from.
: An element, with the same format above.
If element_type is legacy_single_pool_element or single_pool_element, additional fields are as follows:
