Wikipedia
Aftermath!
Aftermath! is a role-playing game created by Paul Hume & Robert Charette which was published in 1981 by Fantasy Games Unlimited.
It is set in a post-apocalyptic world in which the characters typically have to fight for food, water, basic supplies and shelter. The rules are reasonably complex and include many flow charts and tables to enable the Games Master to simulate the world. This leads to a very immersive gaming experience. However, it does require a good knowledge of the rules to play.
The nature of the Apocalypse is up to the Games Master but it is often reminiscent of the Mad Max films. There is even an expansion (Aftermath! Magic!) to play in a universe dominated by dragons in the style of the film Reign of Fire.