I've spent months rewriting Minecraft's villager AI. They farm, build, hold grudges, and bury their dead now (Fabric, no LLM)
Been working on this solo for a while. It swaps vanilla villager AI for handwritten behavior code. No ChatGPT or anything online, it's regular game AI logic like any other mod, so it runs offline and can't make stuff up.
What villagers actually do now: work jobs and get better at them, build houses (with doors, which took me embarrassingly long to get right), farm, mine, marry, raise kids, hold elections, form factions, and bury their dead in a small graveyard at the village edge. They remember how you treat them. Punch one and its family hears about it. Feed one during a famine and it remembers that too.
Left alone they keep themselves alive. Food, shelter, torches, a night watch. My first test village lost half its people in one night. The current version came out of that same test 24 out of 24 alive.
Weirdest thing I've seen it do: one villager walked over and sat with a neighbor who had just lost someone. I didn't code that, it fell out of the grief and empathy systems interacting.
Free, Fabric 1.21.4, beta, so expect some jank. Happy to answer anything.