- There are strong similarities between the plot of this film and that Robert A. Heinlein's short story "Coventry". Both feature a protagonist who is a convict sent to a futuristic penal system which is actually a wilderness outland whose inhabitants have split off into two warring social factions. In the movie, the hero befriends a character known as The Father; in the short story, the protagonist befriends a man named Fader, which resembles the Dutch word "vader", which means "father".
- The helicopter "gunship" is, in actuality, a Russian Kamov Ka-27 'Helix' anti-submarine helicopter. The Helix features a coaxial rotor, and thus looks unfamiliar (and thus potentially futuristic) to Western audiences.