City of Villains (CoV) is a massively multiplayer online role-playing game based on the superhero comic book genre, developed by Cryptic Studios and published by NCsoft. The game was launched in North America on April 28, 2004 and in Europe (by NCsoft Europe) on 4 February 2005 with English, German and French language servers. On October 31, 2005 the game`s first sequel, City of Villains, was launched, allowing players to play as supervillains. Thirteen free major updates (Issues) for City of Heroes have been released since its launch. The newest update, "Power and Responsibility", was released on December 2, 2008. The 14th Issue, called "Architect", has also been announced.

In the game, players create superhero player characters that can team up with others to complete missions and fight villains belonging to various gangs and organizations in Paragon City and its surrounding areas. On November 6, 2007, NCsoft announced their purchase of the City of Heroes/City of Villains intellectual property and is transitioning the Cryptic Development Team over to a new studio in Northern California to continue development on the game.

Players begin by using the game`s extensive character creation system to first select an archetype and Power Sets, then design a unique costume, and finally optionally write a backstory or description and battle cry for their hero as they choose a name. The name may be changed at a later time for a one time charge, and the description and battle cry may be changed at anytime.

The City of Heroes Development Team also initiates events based on North American and European holidays and observances, starting with Halloween in 2004, followed by a Winter Event (eventually becoming a primarily Christmas-themed event), and the newest holiday observance a Valentine`s Day event.

Both City of Heroes and City of Villains are now bundled together when purchased or downloaded, when they were once two separate games with a single subscription fee.