Age of Empires III: The WarChiefs

Age of Empires III: The WarChiefs is the first expansion pack for Age of Empires III, developed by Ensemble Studios and published by Microsoft in 2006. It adds three Native American civilizations - the Aztec, Sioux, and Iroquois - along with new units, technologies, and game modes. The expansion uses proprietary BAR archive files and AGE3X-prefixed scenario and save file formats.