DC Universe Online is a massively multiplayer online role-playing game (MMORPG) set in the DC Universe. Sony Online Entertainment's stated goal is to make a different kind of MMORPG, with The Incredible Hulk: Ultimate Destruction cited as one of the main inspirations for gameplay. SOE is working to make DC Universe Online more interactive than standard MMORPGs, while trying to keep their key elements, which include a leveling system, raid instances, endgame progression and inventories. The world is mainly shared, public space instead of heroes or villains owning territory. The public space features dynamically-generated content designed for both hero and villain player characters (uniquely created by the player, who cannot choose DCU stalwarts).
Players will choose a mentor for their character (Superman, Batman, or Wonder Woman for heroes and Lex Luthor, Joker, or Circe for villains). Their starting location, principal quest rewards and mob loot will be influenced by that decision. The starting zones are either Metropolis or Gotham City, for both heroes and villains. Heroes can also go to the Justice League Watchtower, while villains can enter the Secret Society of Super Villains headquarters at the Hall of Doom. Other safe-houses in the Gotham and Metropolis zones can be reached by teleporters from the two faction headquarters or from the two cities. For the heroes, it's various police stations. For the villains, it's various nightclubs owned by the villains.
Each character is given a communicator appropriate to their faction, via which they receive urgent communications from their mentor and his/her colleagues and subordinates; heroes will frequently receive status updates from Oracle, while villains will receive data from Calculator. In addition to assignments from their mentor, player characters may also receive requests for help from other mentors of the same faction. Player characters may also accept missions from non-player characters (NPCs) in the street, usually minor characters from their faction. There are also opportunities for quick street encounters appropriate to the character's faction: for example, a hero character may encounter a thug robbing an armored truck, trying to break into an office building, or in the process of mugging a citizen; while a villain character may be presented with opportunities to assist NPC thugs with an armored truck robbery, or assault a citizen using an ATM. All NPC interactions are fully animated and voice-acted. Player characters will earn threat ratings that will cause NPC heroes and villains to interact accordingly with the character.
The shared worldspace offers primarily solo and team player versus environment (PvE) gaming opportunities in the form of open air missions and instances, although player versus player (PvP) combat is also possible in this worldspace. Other PvP (and to a smaller extent, PvE) gaming is available in various types of queued instanced encounters: "Legends", small scale PvP combats in which players take on the identities of iconic characters (continued success in Legends combat unlocks additional iconic characters); "Arena", small scale PvP combat in which players fight as their own characters; "Alerts", cooperative team missions; and "Raids", Cooperative PvE missions that are larger than Alerts. Success in PvE missions is rewarded with in-game money, costume pieces, equipment and consumables, while PVP combat is rewarded with unlocks of special equipment sets.