Mobs Love Darkness

Certain mobs have a chance to lock onto torches, lanterns and campfires within a search radius and try to break them. A fixated mob glows, can emit soul fire particles, and plays a distinctive sound once it reaches the light source, then returns to normal behavior. Phantoms can also destroy exposed torches during swooping attacks, so open-air lighting is less safe than covered lighting.

The mod is configurable: the list of eligible mob types, the blocks it targets, the search radius and the goal chance can all be changed, including per-mob-type chances so high-spawn mobs like zombies can be tuned apart from phantoms. Targets that a mob cannot reach are blacklisted for that mob to prevent stuck behavior, and protected blocks from block protection mods are detected and skipped. Search cost grows cubically with radius, so a radius of 128 checks 500 times more blocks than 16, and raising it can noticeably reduce performance; the default vertical search is 4. Performance depends on the machine the server runs on and on the other mods installed beside it.

The mod is a Fabric mod with builds for the range given in its game versions, and its latest Fabric file targets 1.20.1. It is server-side only, so players join without installing it. It is released under the MIT License and is open source.