The WarChiefs offers several enhancements on Age of Empires III, and as with any expansion-pack you must have the original Age of Empires III installed. The enhancement include three new playable Native American civilizations, new Home City cards, new buildings, a new single player campaign, new units, and several other enhancements. The three new native civilizations are the Iroquois, the Sioux and the Aztecs. There are also 6 new maps including: Northwest Territory, California, the Painted Desert, Araucania (which have three varieties: Northern, Southern, and Middle), Orinoco, and the Andes.