DC Universe Online features two expansive city locations that serve as the game's open-world. The cities are split up into different districts or boroughs with various "dungeon areas" accessible from there. Players that choose The Joker or Batman as their mentor will be sent to Gotham City after they complete the Brainiac Harvester Ship introductory level, and Players that choose Superman, Lex Luthor, Wonder Woman or Circe will be sent to Metropolis. Players are free to traverse between the two cities at any level.