 Ensemble Studios released an expansion for the game named Age of Empires III : The WarChiefs on October 17 , 2006 . It contains three new native civilizations that can be completely controlled : The Iroquois Confederation , the Great Sioux Nation , and the Aztecs . New content for existing European civilizations , maps and gameplay additions ( such as the " revolution " feature , in which players can " revolt " from their mother country and start an active military coup in the game ) was added . Both the original game and the first expansion were made available in a single " gold " edition on October 23 , 2007 . 
