MobFilter

MobFilter is a Minecraft mod that allows you to limit spawning of mobs in your world. You can use it to

• Completely prevent particular mobs from ever spawning
• Create safe zones in your world where mobs aren't allowed to spawn.
• Limit mob spawning to specific biomes, times, or light levels
• ...and more

MobFilter uses the Fabric modloader and runs only on the server.

Usage

MobFilter uses a flexible, rule-based filtering system that you configure. When Minecraft wants to spawn a new mob, MobFilter checks the rules you provide to see if the spawn should be 'vetoed.'

The first time you run Minecraft with MobFilter installed, two empty configuration files will be created in the config directory of your minecraft installation: mobfilter.simple and mobfilter.json5.

Simple Configuration (mobfilter.simple)

Only available in versions 0.19.0+1.21.7 and later.

If you just want to remove some mobs from the game, edit mobfilter.simple and add a list of the mob ids that you want to prevent spawning:

# I never want to see these mobs again:
minecraft:creeper
minecraft:phantom
minecraft:silverfish

You can also use negations and wildcards to filter out most or all of the mobs in a namespace:

# I love cats, so don't filter them...
!minecraft:cat

# ...but I don't want ANY other vanilla mobs
minecraft:*

See the documentation for more details.

Advanced Configuration (mobfilter.json5)

If you need more detailed control over mob spawning, you can instead edit mobfilter.json5. This file is a bit more complicated to configure but it allows your filtering logic to test for more complicated conditions, including:

• Block Position
• Location (Biome, World, Dimension, BlockId)
• Mob Type (EntiyId or SpawnGroup)
• Time of Day
• Light Level
• Phase of moon

For example, if you want to prevent hostile mobs from spawning in a specific area, you could add a rule like this:

{ 
  rules : [
    {
      name : "Safe Zone",
      what : 'DISALLOW_SPAWN',
      when : {
        category : [ 'MONSTER' ],
        dimensionId : [ 'minecraft:overworld' ],
        blockX: [ -128, 234 ],
        blockY : [ 63, 'MAX' ],
        blockZ : [ -321, 512 ]
      }
    }
  ]
}

See the documentation for more details.

Why This Mod?

I wrote this mod because I wanted to be able to be able to play survival minecraft with my daughter, and that meant we had to have a mob-free area around our base. There are numerous other mods out there that manage mob spawning but none of them did quite what I needed them to do.

Backports?

As a rule, I don't do backports unless critical security issues are involved. It's just too much tedious work to backport every mod feature to every old version. But I'm happy to accept PRs if you want to do one yourself.

Legal

This mod is published under the MIT License.

You're free to include this mod in your modpack provided you attribute it to pcal.net.

Questions?

If you have questions about this mod, please join the Discord server:

https://discord.pcal.net