Yukari's Spiriting Away

A server-side only Minecraft 1.20.1 / Forge mod that disables selected status effects, entity spawns and damage types through a config file. All matching is based on registry IDs (modid:key), so status effects, entities, damage types and dimensions added by other mods can also be configured.

Globally disable status effects — globallyDisabledEffects

Format: modid:effectid

globallyDisabledEffects = ["minecraft:resistance"]

Prevent a specific entity from gaining a specific effect — entityEffectBans

Format: modid:entityid&modid:effectid (entity first)

entityEffectBans = ["minecraft:iron_golem&minecraft:health_boost"]

Meaning: Iron Golems cannot gain Health Boost.

Globally disable entity spawns — globallyDisabledSpawns

Format: modid:entityid

globallyDisabledSpawns = ["minecraft:creeper"]

Disable entity spawns in a specific dimension — dimensionSpawnBans

Format: modid:dimensionid&modid:entityid

dimensionSpawnBans = ["minecraft:the_end&minecraft:enderman"]

Meaning: Endermen no longer naturally spawn in the End.

Disable a mod's entities in a specific dimension — modLivingDimensionSpawnBans / modNonLivingDimensionSpawnBans

Format: modid&modid:dimensionid (the first part is the entity registry namespace, i.e. the mod id)

modLivingDimensionSpawnBans    = ["minecraft&minecraft:the_end"]   # no vanilla living entities in the End
modNonLivingDimensionSpawnBans = ["minecraft&minecraft:the_end"]   # no vanilla non-living entities (items/projectiles/minecarts...)

Meaning: disables a whole mod's (by registry namespace) living or non-living entities in a specific dimension. This rule is based on EntityJoinLevelEvent and is more thorough than the spawn bans above:

• Covers both living and non-living entities, including dropped items, projectiles, minecarts and other entities that never participate in natural spawning;
• Not only prevents new spawns — entities already present in the dimension are removed when their chunks load; spawn eggs and /summon are also ineffective.

Warning: disabling all of a mod's entities like in the example can easily break the world — use with care. Note in particular that players are also LivingEntity: if modLivingDimensionSpawnBans bans the minecraft namespace in the End, players entering the End will be removed outright.

Globally replace damage types — damageReplacements

Format: modid:damagetypeid or modid:damagetypeid&modid:newdamagetypeid

• With one segment only, the damage is replaced with minecraft:mob_attack;
• With two segments, it is replaced with the specified new damage type.

damageReplacements = [
    "minecraft:on_fire",                       # fire damage → mob_attack
    "minecraft:player_attack&minecraft:mob_attack",
]

Entity damage rules (immunity / replacement) — entityDamageRules

Format: modid:entityid&modid:damagetypeid or modid:entityid&modid:damagetypeid&modid:newdamagetypeid

• With two segments, the entity is immune to that damage;
• With three segments, the damage the entity takes is replaced with the new damage type.

entityDamageRules = [
    "minecraft:creeper&minecraft:on_fire",                            # creepers are immune to fire damage
    "minecraft:creeper&minecraft:on_fire&minecraft:mob_attack",       # fire damage taken by creepers becomes mob_attack
]

Notes and limitations

• Effect disabling only prevents new applications; effects that are already active expire naturally and are never actively removed.
• Spawn bans cover natural spawning, spawners and other FinalizeSpawn paths; /summon and entities already present in loaded chunks are unaffected.
• Damage replacement is resolved as if the damage was originally the new type (armor reduction, invulnerability checks, etc. all follow the new damage type).
• Damage types that are configured but not registered fall back to minecraft:mob_attack, and a warning is logged once in the server log.