This is one continuously running world on the server. Everything here happens now, as you watch — nothing is precomputed, replayed or staged.
Real (simulated)
Terrain, weather, seasons, temperature, rain, wind and snow.
Finite materials: every pole, log, reed and stone is gathered and carried.
Buildings are programs of posts, beams, panels and features. Physics checks what each piece rests on and whether its material can carry the load; shelter from rain and wind is measured by casting rays through the actual surfaces.
Villagers hold their own beliefs about materials. Designs that exceed the real strength sag or collapse, and the builders learn from it.
Needs, warmth, wetness, sleep quality, memories, relationships, knowledge that spreads by teaching and watching.
Wildlife that grazes, flees, hunts, raids food stores and breeds — and animals people tame, pen and keep.
Who decides
The villagers' minds are a utility-and-planning system with personalities. Their thought text is written from the goal and reasons they actually acted on.
Decoration
Faces, clothes, paint patterns and small visual jitter reflect a person or builder's taste; they do not change performance.