The fictional universe is the imaginary world in which adventures take place. In a sense, all role-playing games have a fictional universe, since the events of a game never really happened. It is especially used, however, to describe either a wholly imaginary world (such as Greyhawk) or the canon of events within a fiction (such as the James Bond movies, or conversely, the novels).
Alternate terms: virtual reality, imaginary universe, fictional world, imaginary world, sandbox, milieu