Entities, Spawners & Markers

Entities, Spawners and Markers are what you use to spawn mobs in your world. You find & create entities, entity spawners and markers in the 'entities', 'spawners' and 'markers' folder respectively.



    "type": "ZOMBIE"

type is the type of mob or animal that this entity controls. Use autocompletions to get all possibilities.

5 Elements

Five other settings that you will likely need when setting up an entity are:

    "spawnEffectRiseOutOfGround": true
    "helmet": {},
    "chestplate": {},
    "leggings": {},
    "boots": {},
    "mainHand": {},
    "offHand": {},
    "customName": "&cRed",
    "rawCommands": []

Spawn Effect

spawnEffectRiseOutOfGround will cause mobs to dig out of the ground, as if they were underground. This is a pretty cool effect, but you may not always want this.


helmet, chestplate, leggings and boots are equipment for the mob. Not all mobs have support for showing these items, and mobs that do not display this equipment (e.g. fish) may not always carry the benefits (protection).


mainHand and offHand are what you can use to equip mobs with weaponry directly. They are for the main- and offhand respectively. You can give any item with any enchantment, and even include custom properties (like extra/less health, more/less damage, etc).

Custom Name

customName allows you to specify a name for the mob. You can use colors with the & key. Open the link below for the possible colors (no RGB possible, unfortunately) and effect (italic and bold etc.)

Raw Commands

rawCommands allows you to run raw commands at that specific location. You can specify commands to run with a delay, run on a loop, and set the loop delay.

"rawCommands": [{
    "commands": [
        "kill cocodef9",
        "setblock {x} {y} {z} diamond_ore"


Before we start with spawners, we will quickly go over the concept of energy. Energy is generated constantly in Iris worlds, based on how many players are online and how many chunks are loaded. The more players & chunks, the more energy is generated.

When a mob spawns, it takes some energy. This is designed so that not too many mobs can exist in your world at once.

In your Configuration you can specify the targetSpawnEntitiesPerChunk (default 0.95) which allows you to directly modify the amount of energy in the world. If you set this to 2, twice as many mobs will spawn.


    "spawns": []


spawns allow you to set a list of entity spawns, such as:

    "entity": "standard/passive/tropical-fish",
    "maxSpawns": 15,
    "minSpawns": 7,
    "rarity": 10,
    "energyMultiplier": 2

Where entity contains the link to the entity in the entities folder (see above), max & minSpawns allow you to set the maximal and minimal amount of entities per chunk. The rarity allows you to set the amount of chunks this is done in (every 1 in rarity chunks has this spawn applied to it). Lastly, energyMultiplier allows you to set the factor of additional energy that this spawn table uses.

5 Elements

Five other settings that you will likely need when setting up a spawner are:

    "group": "BEACH"
    "initialSpawns": [],
    "maxEntitiesPerChunk": 1,
    "allowedLightLevels": {},
    "weather": "ANY"    


group allows you to set the area where these mobs can spawn. When set to NORMAL, they will spawn on land. When set to CAVE they spawn in caves, etc.

Initial Spawns

initialSpawns allow you to specify a list of mobs that (while still taking energy) spawn at the start (when the chunk is first loaded). These still take the maxEntitiesPerChunk into account.

Max Entities

maxEntitiesPerChunk is the setting that lets you specify a number. This number is what Iris uses to check as follows: If there are more than number mobs in the chunk, do not spawn mobs from this spawner. The amount of mobs in a chunk includes other mobs from other spawners.

Light Levels

allowedLightLevels allows you to specify a min and max amount of light required before the mob can spawn at any given location. These values range from 0 to 32.


weather allows you to set the weather condition, under which the mobs in this spawner can spawn. If set to ANY (default), mobs can spawn regardless of weather.



    "removeOnChange": true,
    "spawners": ["igolem"],
    "emptyAbove": true,
    "exhaustionChance": 0.01

Remove on change

removeOnChange allows you to have the marker removed after the block it marked changes.


spawners is the list of spawners (see above) that can spawn mobs on these markers.

Empty Above

emptyAbove, when set to true, the block(s) above the marker must be empty to spawn a mob on it.


exhaustionChance is the chance (0.1 = 10%) that the marker is removed after any spawn

Add to Object placement

"markers": [
        "mark": [
                "block": "minecraft:grass_block"
        "maximumMarkers": 5,
        "marker": "name",
        "exact": true


mark allows you to specify a list of blocks which are marked to spawn a mob on.

Maximum Markers

maximumMarkers is the maximal amount of markers that spawn on this structure (for this marker)


marker is the marker that is applied to this object


exact is the setting that lets you make sure that your specific block conditions / block combinations are met when the mob is spawned.

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