Better Spawner/Spawn Condition

A SpawnCondition is the most important component of the Better Spawner system, and tells the spawner when and where to spawn entities.

If a particular property is not mentioned in the condition, then any value is acceptable.

The properties of a SpawnCondition are as follows:

Property label	Type of value	Description
"times"	List of any of the following: "DAWN","MORNING","DAY","MIDDAY","AFTERNOON","DUSK","NIGHT","MIDNIGHT".	The times of the day that the entity may spawn.
"weathers"	List of any of the following: "CLEAR","RAIN","STORM".	The weather types which the entity may spawn in. Note that snow will also count as rain (and snowstorms as normal storms).
"stringBiomes"	List of any number of biomes, using their ID name (such as "redwood_taiga_hills").	All the biomes that the entity may spawn in. Supports modded biomes from mods such as Biomes O' Plenty, and pre-made categories containing multiple biomes to spawn in.
"dimensions"	List of numbers	The dimensions that the entity may spawn in. Having a list with only 0, for example, would make an entity only spawn in the regular overworld.
"worlds"	List of text	The names of the worlds in which the entity may spawn.
"minX"	Integer	The smallest x world coordinate that the entity may spawn at.
"maxX"	Integer	The largest x world coordinate that the entity may spawn at.
"minY"	Integer	The smallest y world coordinate that the entity may spawn at.
"maxY"	Integer	The largest y world coordinate that the entity may spawn at.
"minZ"	Integer	The smallest z world coordinate that the entity may spawn at.
"maxZ"	Integer	The largest z world coordinate than the entity may spawn at.
"seesSky"	Boolean (true/false)	Whether the sky must be visible or must not be visible for the entity to spawn. Not including this option means it does not care whether it can or not.
"moonPhase"	Integer from 0 to 7	The specific moon phase index for the entity to spawn. 0 represents a full moon.
"minLightLevel"	Integer from 0 to 15	The minimum level of light for the entity to spawn.
"maxLightLevel"	Integer from 0 to 15	The maximum level of light for the entity to spawn.
"tag"	Text	A needed tag on the SpawnInfo. For example, legendary Pokémon often have multiple tags, one of which is legendary.
"temperature"	One of any of the following: "OCEAN", "COLD", "MEDIUM", "WARM"	The temperature category needed for the entity to spawn. These temperature categories are per biome.
"baseBlocks"	List of text	The block IDs that this entity may spawn on. These are things like minecraft:stone, or one of the block categories. This does not support meta values for differentiating, for example, stone from andesite.
"variant"	List of text	The variant names needed for the base block. This is mainly used for Headbutt, and uses things like birch, ebony, and willow in this list to specify what types of logs are acceptable.
"neededNearbyBlocks"	List of text	The block IDs that this entity must have nearby in order to spawn. These are things like minecraft:water, or one of the block categories. This does not support meta values for differentiating, for example, stone from andesite.

Note that all properties of a SpawnCondition are optional. If added as an anticondition to a SpawnInfo, passing the anticondition will prevent the spawn. For example, an anticondition that specifies "minX" and "maxX" is added to a SpawnInfo, then the entity will spawn everywhere except for between those two x coordinates. Combining this with a regular condition which has "times": ["DAY"] would result in the entity being unable to spawn within those coordinates during the day.

Combining conditions and anticonditions can make extremely specific behaviour.