Post Apocalyptic

Whether it was caused by a natural event or a man-made disaster hardly matters at this point - the catastrophe that struck our planet has come and gone, leaving unimaginable death and destruction in its wake. For more information, see the "Disaster Movie" tag.

Now it's up to the survivors to save what can be saved, and, if it's still possible, undertake the difficult process of rebuilding, with the full awareness that nothing will ever be the same again. Post-apocalyptic tales, the undisputed stars of cinematic sci-fi of the 1970s and '80s, thus tend to focus on a group of individuals grappling with an impoverished, barbaric situation. (+)

The collapse of society and civilized values, along with a chronic lack of resources and know-how, inevitably leads to a dystopic, backward milieu.
Consequently, the canonical ingredients of the genre include a return to violence and relationships based on brute force (a mindset along the lines of "homo homini lupus est"), a lost or distorted historical memory, and a revival of mysticism and/or religion, with the advent of new cults and beliefs, often characterized by euhemeristic tendencies. Events often unfold in a climate of anarchy and confusion, due to periodic incursions of looters and pillagers, the insane behavior of wannabe dictators, or, more generally, to the overwhelming weight of superstition and irrationality.