This is a list of fictional universes, organized by genre, by sub-genre and/or by medium. The term universe can be misleading, since some of them are supposed to occur in our own world, but in a fictional future (sci-fi) or past (Hyborian Age) timeline.
Science fiction
Novels and short stories
Comic books
Television and movies
Fantasy
Pseudo-medieval fantasy worlds
This is the most common type. Social conditions are modeled on medieval Europe although many stories have numerous gods and goddesses that suggest polytheism. See also High fantasy.
Planetary Romance
Planets with fantasy trappings and usually magic and/or a pretext why swords and other melee weapons are necessary. Barsoom tales are close runner. Many of the earlier tales were fantasy thinly disguised as science fiction.
Multidimensional fantasy worlds
Some stories take place in a series of connected universes (see: multiverse). Noted for this include:
Other
Imaginary universes in literature
Fictional universes in film and television
Fictional universes in comic books
See also: List of campaign settings.
Fictional universes in video games