MobRules

Mod Capabilities

MobRules is a lightweight addon for Minecraft 1.21.1 that provides detailed control over creature spawning in the game. The mod divides all mobs into three main groups:

• Hostile Mobs: all aggressive creatures, including monsters, undead, and other threats
• Farm Animals: tamed and peaceful land creatures, typically used for resource gathering or as companions
• Aquatic Inhabitants: all creatures living in water - from fish to amphibians

For each category, three levels of control are available:

• Allow All (false): standard mob spawning behavior as in the original game
• Block All (true): completely prevent creature spawning in the entire category
• Selective Control (partial): use customizable JSON allowlists to precisely specify which mobs can spawn

Advanced Configuration

When selecting "partial" mode, MobRules automatically creates files with lists of allowed mobs in the config/mobrules/ folder:

• hostile_mobs_allowlist.json - manages hostile mob spawning
• farm_animals_allowlist.json - controls farm animal spawning
• aquatic_animals_allowlist.json - regulates aquatic inhabitant spawning

These files are created with reasonable default settings and can be edited to include only those mob identifiers you want to allow. For example:

[
  "minecraft:zombie",
  "minecraft:skeleton",
  "minecraft:creeper"
]

Who MobRules Is For

Every Minecraft player has encountered situations where standard creature spawning mechanics don't align with their goals:

• Creative builders who want to draw inspiration from a living world without interruptions from combat encounters
• Server administrators managing performance through selective creature populations or creating themed areas
• Modpack creators who need precise control over which creatures populate their custom worlds
• Accessibility-focused players who want to reduce specific stress factors while maintaining gameplay
• Role-playing servers requiring specific atmospheric conditions with custom creature populations
• Adventure map makers who need exact control over which mobs spawn in different areas

MobRules bridges the gap between standard creature spawning in Minecraft and the diverse needs of the community, offering everything from simple on/off switches to precise per-mob control through easily editable configuration files.