Eight hundred years ago, everything went to hell. Cities vanished, forests burned, and an entire civilization died in nuclear fire, gengineered plagues, and mutagenic poisons. Gamma Terra is what's left, a world blighted by radioactive deserts, deadly ruins, and thousands of new and dangerous species armed and armored with bizarre mutations and the wreckage of technology. Humanity is no longer the master of the world. Strap on your sword and ready your blaster - it's time to brave the wild frontiers! This fresh new look at a classic campaign setting is designed for the ALTERNITY science fiction roleplaying game. This book contains everything a Gamemaster and player needs to create and play adventures in GAMMA WORLD, including a condensed version of the ALTERNITY game rules, customized to the GAMMA WORLD setting. Play a pure strain human, mutant, or any of four other hero species. Looking for mutations? Choose from 120 different ones, including many old favorites updated for the new edition. Select one of four professions, and build your hero from an array of nearly 100 different skills. Pick from dozens of weapons for your hero, ranging from swords and crossbows to BattleKlaws and blaster rifles. Battle any of over two dozen mutated denizens of GAMMA WORLD, or test you strength against the dreaded Cryptic Alliances! Includes three adventure designed as a framework for a Gamemaster's GAMMA WORLD campaign.