Gurps

Watch the Skies! Alien invaders! Giant lizards from another age! Flesh-eating zombies! Colossal insects! Mad scientists! Blobs! Only you can defend humanity, civilization, and the American Way from these terrible horrors. GURPS Atomic Horror contains everything you need to roleplay the science-fiction and horror movies of the 1950s. The campaign can be as scary as The Thing, as dramatic as The Day the Earth Stood Still, as strange as Little Shop of Horrors or as goofy as Plan 9 From Outer Space - the choice is yours. Characters can be square-jawed scientists and military men, heroic explorers, misunderstood teenagers, cold-war spies, G-men, gangsters . . . or just ordinary folks caught up in unearthly weirdness.