The original universe of the Armored Core franchise. In it, Mankind was forced underground due to the aftermath of the Great Destruction, a cataclysmic war. In the underground era, Corporations emerged to control the world and their battles lead to the rise of the Muscle Tracer and eventually the titular Armored Core. However, it was revealed that all of these events were the machinations of an AI known as Hustler One. With its destruction by Leos Klein, a new Government emerged to reign in both the Corporations and Ravens.