"SF0 is a collaborative and immersive game set in San Francisco. The goals of play include meeting new people, exploring the city, and participating in creative non-consumer leisure activities."

The game seeks to be an open structure, a context for interacting with the city and the people who live in it. Players are asked to engage in a variety of collaborative activities (also known as "tasks") relating to different aspects of city life. They are also given the opportunity to create activities for other players. Although the game interface is web-based, actual game play almost always takes place in the real world.

The site combines elements of social networking, blogging, messaging and file sharing to produce an effective mechanism for collaborating on projects of any kind.