Tropos is one of the extra-terrestrial planets that comprise the setting to the Fighting Fantasy gamebook Rebel Planet. It is depicted as being the first planet colonised by Humans, being only 6.8 light years from Earth. Because it was colonised relatively early (late 21st century), its customs, fashions and technology are more dated than that of the other planets colonised by Humans, Radix and Halmuris. Like the other planets, it has been invaded and occupied by the Arcadian Empire. Most of the Arcadians living there are of the aggressive Northern species, most certainly due to an active Human underground.