Just Another Spawner Mod — Guide
Tags and Logic System
The heart of JAS is its tag system, which allows for complex boolean and numeric logic. Tags are used in the Spawn Tag and Despawn Tag fields of the configuration files.
Boolean Tags
These tags return true or false to allow or block a spawn.
spawn: The primary tag for allowing a spawn.despawn: Controls if an entity should be removed when far from players.!: The NOT operator (e.g.,!solidsidemeans the block must not have a solid side).
Property Tags (v0.14.0+)
These tags check environmental variables at the spawn location.
| Tag | Description | Example |
|---|---|---|
light(min,max) |
Checks the light level at the feet. | light(0,7) |
sky |
Returns true if the block can see the sky. | sky |
height(min,max) |
Checks the Y-coordinate. | height(0,64) |
difficulty(id) |
Checks the world difficulty (0=Peaceful, 3=Hard). | difficulty(2,3) |
dimension(id) |
Restricts spawning to specific dimension IDs. | dimension(-1) |
liquid |
Returns true if the spawn block is a liquid. | liquid |
solidside(dir) |
Checks if the side of a block is solid. | solidside(1) |
opaque |
Checks if the block is opaque. | opaque |
random(chance) |
Adds a random percentage chance to the spawn. | random(50) |
block(id, meta) |
Checks for a specific block at the spawn location. | block('minecraft:grass', 0) |