How a world runs
Each cycle begins with a small set of newly generated kingdoms: rulers, cultures, terrain, and starting relationships. From there the simulation advances in discrete steps, resolving succession, diplomacy, famine, plague, war, and the occasional dragon or villain, purely from the state of the world at that moment. Nothing is pre-written. A cycle can run for centuries of in-world time before it fails, resets, or is sealed as a notable record.