Civilizations now enter Dark Ages or Golden Ages based on their Era Score. High scores lead to Golden Ages with powerful bonuses, while falling behind triggers Dark Ages, though a successful recovery from a Dark Age can lead to a super-powered Heroic Age .

The expansion adds significant depth to the base game with several new mechanics:

Includes 8 new civilizations (such as the Cree, Mongols, and Dutch) and 9 new leaders, each with unique units and abilities. Where to Download

Alliances now provide greater benefits the longer they are maintained. The expansion also introduces Emergencies , where nations can unite against a common threat, such as a civilization using nuclear weapons or conquering a city-state.

Players can recruit and promote specialized Governors to manage cities, providing unique bonuses to loyalty, production, and defense.