The world is set hundreds of years in the future, after a catastrophic event nearly destroyed civilization. Massive abandoned cities, broken skyscrapers, overgrown highways, and forgotten technology remain scattered across the earth, while new cities have been built around strict social classes. Everyone is given a technological wrist device that determines their identity, status, and privileges. Those without one are considered lower than citizens and are forced to live outside the official cities, often in dangerous, lawless settlements.