Apocalyptic and post-apocalyptic fiction is a subgenre of science fiction , science fantasy , dystopia or horror in which the Earth's or another planet's civilization is collapsing or has collapsed. The story may involve attempts to prevent an apocalypse event, deal with the impact and consequences of the event itself, or it may be post-apocalyptic, set after the event. The time may be directly after the catastrophe, focusing on the psychology of survivors, the way to keep the human race alive and together as one, or considerably later, often including that the existence of pre-catastrophe civilization has been mythologized. Post-apocalyptic stories often take place in a non-technological future world or a world where only scattered elements of society and technology remain.