Apocalyptic / Post-apocalyptic
What is it?
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 frame may be immediately after the catastrophe, focusing on the travails or psychology of survivors, the way to maintain the human race alive and together as one, or considerably later, often including the theme that the existence of pre-catastrophe civilization has been forgotten (or mythologized). Post-apocalyptic books often take place in a non-technological future world, or a world where only scattered elements of society and technology remain.