Age of Empires III: The WarChiefs

Age of Empires III: The WarChiefs, the first expansion for the real-time strategy game Age of Empires III, came out in the United States on October 17, 2006. It was later bundled with the base game as the Age of Empires III Gold Edition, released on October 23, 2007. A Mac version, developed and published by Destineer's MacSoft, followed on June 12, 2007, in the United States. A second expansion, Age of Empires III: The Asian Dynasties, came afterward.

The expansion does not overhaul the core gameplay—players still gather resources, build armies, and attack opponents—but it introduces several new concepts and expands on existing ones. The Aztecs have a home city, while the Iroquois and Sioux use a Tribal Council with five members: the Chief, War Leader, Shaman, Wise Woman, and Messenger. These council members offer different units, supports, and improvements. When a native civilization advances in age, the Tribal Council replaces the European politician system; the player promotes a candidate to the council, gaining a bonus. Later ages provide higher bonuses, with the same type of bonus (extra units or resources) persisting, and new candidates become available at higher home city levels.

New minor native tribes are added, increasing the original 12 to 16. The Huron replace the Iroquois, the Cheyenne replace the Lakota (Sioux), and the Zapotec replace the Aztec. Other new tribes include the Klamath, Apache, Navajo, and Mapuche.

All Native civilizations have a Fire Pit. Villagers can perform dances there, with up to ten dances per civilization. Dances are learned through Home City shipments, such as the Town Dance (improves building HP and attack) and the Water Dance (improves naval combat). The Iroquois have the unique Founder Dance, which spawns new Travois, and the Earth Mother Dance, which increases maximum population. The Sioux have the Fire Dance, which increases unit damage to buildings and ships to compensate for their lack of siege weapons, and the War Song Dance, which produces free Dog Soldier cavalry. The Aztecs have the Healing Dance (idle units automatically regenerate health) to offset limits on Warrior Priests, and the Garland War Dance to spawn free Skull Knights.