A campaign setting is usually a fictional world which serves as a setting for a role-playing game or wargame campaign. A campaign is a series of individual adventures, and a campaign setting is the world in which such adventures and campaigns take place. Usually a campaign setting is designed for a specific game (such as the Forgotten Realms setting for Dungeons & Dragons) or a specific genre of game (such as Medieval fantasy, or outer space/science fiction adventure). There are numerous campaign settings available both in print and online. In addition to published campaign settings available for purchase, many game masters create their own settings, often referred to as "homebrew" settings or worlds.