Armored Core 4 is the 12th installment of the Armored Core series despite being titled Armored Core 4. Armored Core 4 is set in the future, where a great war has left the nations of Earth devastated and their respective governments taken over by corporations. The game features a system for personalized customization of the player's AC and an online mode where players can battle each other over either the PlayStation Network or Xbox Live.