Supreme Ruler is a computer strategy game in which a player controls a region's government and attempts to conquer a fictional world of fragmented states. The game simulates raising funds through taxes and spending on agriculture, government services, and the military. Up to 9 regions play at once, either human hotseat or AI controlled, and all actions are resolved simultaneously at the end of each turn. The design of Supreme Ruler was influenced by earlier nation-state simulations such as Sumer, though the concept is taken further with the addition of multiplayer, military battles, and a more sophisticated design.