Spawners

A spawner is a point in a world that keeps a population of one mob alive around itself. It wakes when a player comes near, spawns up to a cap, refills what dies, and can pull back anything that wanders too far. Spawners live in Mobs/, beside the mobs they spawn — not in a folder of their own.

Two ways to declare one

Nested under the mob, when the spawner belongs to that mob:

zombie_knight:
  base: zombie
  health: 40
  spawners:
    crypt_door:
      at: world, 128, 40, -310
      spawn: { amount: 2, max: 6 }
      timer: { every: 30s }

In a top-level spawners: block, whose sections are groups and can nest as deep as you like:

spawners:
  crypt:
    defaults:
      activation: { range: 32 }
      timer: { every: 20s }
    entrance:
      mob: zombie_knight
      at: world, 128, 40, -310
    throne:
      mob: lich
      at: world, 140, 32, -350
      spawn: { max: 1 }
      timer: false

The id is the path it sits at (crypt.entrance), and the group is the section it is in — so ids are unique for free and /le spawner disable crypt means something. defaults: is inherited by everything below it, and a spawner that names a setting itself always wins.

spawners is a reserved top-level key in Mobs/ files. A mob cannot be called spawners.

Position

Every spawner needs one. Write it however you like — all of these are the same spot:

  at: world, 128, 40, -310      # one string, commas or spaces
  at: { world: world, x: 128, y: 40, z: -310 }
  world: world                  # ...or as four plain keys,
  x: 128                        #    which is also how MythicMobs spells it
  y: 40
  z: -310

location: and pos: are accepted as synonyms for at:.

Key	Also	Default	What it does
`radius`	`radiusxz`, `spread`	`0`	Horizontal scatter around the point, up to 256.
`radius-y`	`radiusy`	`0`	Vertical scatter, up to 256.

Settings

Every key is read case-insensitively with - and _ interchangeable, so a MythicMobs spawner loads as-is — the MythicMobs name is listed under “also”.

`spawn:`

Key	Also	Default	What it does
`amount`	`mobsperspawn`	`1`	Mobs per cycle, 1–64.
`max`	`maxmobs`	`1`	Population cap, 1–1000.
`level`	`moblevel`	`1`	The level mobs are tagged with.
`chance`	—	`1.0`	Probability a due cycle actually fires, 0–1.
`random-rotation`	`randomrotation`	`false`	Spawn facing a random direction.
`world-scaling`	`useworldscaling`	`false`	Derive the level from distance to world spawn instead of `level`.

`timer:`

Key	Also	Default	What it does
`enabled`	`usetimer`	`true`	`timer: false` is the short way to say “only fires when triggered”.
`every`	`cooldown`	`10s`	Time between cycles.
`warmup`	—	`0`	Delay after waking before the first cycle.

Durations here take a bare number as seconds (every: 30 is 30 seconds), matching MythicMobs, and also accept 30s, 2m, 400t.

`activation:`

Key	Also	Default	What it does
`players`	`check-for-players`, `checkforplayers`	`true`	Whether a player has to be near for it to run at all.
`range`	`activationrange`	`40`	How near.

Going back to sleep re-arms the warmup, so returning to a dungeon makes you wait again.

`leash:`

Key	Also	Default	What it does
`range`	`leashrange`	`0` (off)	Blocks a mob may stray before it is teleported home.
`heal`	`healonleash`	`false`	Heal it fully when it returns.
`reset-threat`	`resetthreatonleash`	`false`	Make it forget its target — see Factions & Threat.

leash: 32 is shorthand for leash: { range: 32 }.

Top-level

Key	Default	What it does
`mob`	the mob it is nested under	Which mob to spawn. Required for a spawner in a `spawners:` block.
`group`	the section it sits in	Override the group name.
`enabled`	`true`	Whether it starts switched on.
`breakable`	`false`	Mining its block switches it off.
`flames`	`false`	Show the vanilla spawner flame particles.
`conditions`	none	See below.

Conditions

A list of place-shaped tests, all of which must pass before a cycle spawns anything:

  conditions:
  - night
  - light <= 7
  - biome == desert, badlands
  - y > 40
  - !raining

A line is key, !key, or key <op> value with == != >= <= > < (spaces optional, = accepted for ==). String comparisons are case-insensitive, ignore a minecraft: namespace, and take a comma list meaning “any of these”.

Flags	Numbers	Names
`day`, `night`	`y` / `height`, `light`, `blocklight`, `skylight`	`biome`
`raining`, `thundering`, `clear`	`time`, `moonphase`, `random` / `chance`	`world`
`spawnable`, `ground`	`players`, `mobs`, `distancefromspawn`	`block`, `blockbelow` / `onblock`

A condition that fails to parse disables its spawner rather than being skipped. A gate that silently disappears spawns mobs exactly where you said not to. /le debug Spawners names the line and the reason.

Behaviour worth knowing

At the cap the timer simply waits. No cooldown is burned, so the spawner refills promptly once something dies rather than idling for another full cycle.
A restart does not double the population. Every spawned mob carries its spawner’s id, and is adopted back as its chunk loads, so a restarted dungeon is not filled a second time.
Warmup re-arms on sleep. Walking away and coming back makes you wait through the warmup again.
breakable disables rather than deletes. MythicMobs removes the spawner outright; here the YAML is left alone, because config a player can destroy with a pickaxe shouldn’t vanish silently. /le spawner enable <id> puts it back.
Spawners never force-load chunks, and skip worlds that aren’t loaded.
Runtime state is not config. Cooldowns, warmups and live counts live in memory; only “an admin switched this off” persists, in spawner-state.yml.

Server-wide switches

spawner:
  enabled: true        # turn every spawner off at once
  check-interval: 20   # ticks between passes; 20 = once a second
  world-scaling:
    blocks-per-level: 250
    max-level: 20

Driving them

From commands: /le spawner: list, info, create, remove, enable, disable, reset, trigger, tp. From an effect, which is what makes a spawner part of an encounter rather than scenery:

- spawner{id=crypt.entrance;action=trigger} +onInteract    # spawn a wave now
- spawner{id=crypt;action=disable}          +onDeath       # the boss dies, the whole group stops
- spawner{id=crypt;action=reset}            +onSpawn       # ...and starts fresh next time

action is trigger, enable, disable, reset (keep the mobs) or clear (remove them too). Everything but trigger accepts a group name or all. From code: LodeEntitiesAPI.spawners().

NPCs on fixed spots

A spawner with the default spawn.max of 1 and a short timer keeps exactly one mob standing on a spot, facing yaw. That is how an NPC is placed:

shopkeeper:
  type: npc
  base: villager
  ai: false
  persistent: true
  spawners:
    market:
      at: world, 120.5, 64, -40.5
      yaw: 90
      timer: { every: 5s }
      activation: { players: false }

A persistent mob is taken back by its spawner after a restart rather than spawned a second time.

Coming from MythicMobs

Drop a MythicMobs spawner file into Mobs/ and it converts on load, field by field, the original kept as <name>.mm-bak. Every MythicMobs spawner field is supported: MobsPerSpawn, MaxMobs, MobLevel, Chance, RandomRotation, UseWorldScaling, UseTimer, Cooldown, Warmup, CheckForPlayers, ActivationRange, LeashRange, HealOnLeash, ResetThreatOnLeash, Radius, RadiusY, ShowFlames, Breakable and Conditions. CooldownTimer, WarmupTimer and ActiveMobs are deliberately not config here: they are runtime state. Conditions convert when they are location-shaped (daytime/night, weather, biome, world, blocktype, onblock, height, lightlevel, moonphase, distancefromspawn, playerwithin, mobsinradius, chance, with MythicMobs’ >60 and 40to60 ranges). Anything else is kept as a comment and the spawner is imported without it; check /le debug Spawners after importing.

Getting Started

Mobs

Spawning

Commands

Effects

Models

Compatibility

NPCs

Pets

Configuration

API

Two ways to declare one

Position

Settings

`spawn:`

`timer:`

`activation:`

`leash:`

Top-level

Conditions

Behaviour worth knowing

Server-wide switches

Driving them

NPCs on fixed spots

Coming from MythicMobs

​Two ways to declare one

​Position

​Settings

​spawn:

​timer:

​activation:

​leash:

​Top-level

​Conditions

​Behaviour worth knowing

​Server-wide switches

​Driving them

​NPCs on fixed spots

​Coming from MythicMobs

Two ways to declare one

Position

Settings

`spawn:`

`timer:`

`activation:`

`leash:`

Top-level

Conditions

Behaviour worth knowing

Server-wide switches

Driving them

NPCs on fixed spots

Coming from MythicMobs