Civilization IV is a turn-based game in which the player builds an empire from scratch. It begins in the Ancient Era (4000 BC) with a single Settler. From there, the player expands the empire while contending with rivals, utilizing the terrain, and developing technology. There are many obstacles to face, modeled on political or economic problems faced by real-world nations. Develop your empire's culture, military, technology, and diplomacy to become the premier civilization to stand the test of time.