Armored Core 4 is the 12th installment in the Armored Core series . The games are set in an alternate universe where corporations fight wars and have taken over governmental control. Due to the growth of the population, food and energy became scarce and widened the gap between the rich and the poor. Anarchy ensued and the government lost control of the situation. People turned to the corporations to provide for safety.
The player takes on the role of a member of the Ravens, a rebel group who wants to challenge the modern slavery by force. The player controls a giant Mech, part of a squad, which can be assembled with available parts, and customized with weapons, paint, and aesthetic options.
Five years after the establishment of Pax Economica, 2007, the player fights Mechs from corporations in 30 missions grouped together in chapters. At the end of each level, new parts become available and the Mech can be repaired with wages. Multiplayer is supported over the PlayStation Network and Xbox Live.