Just as a single change to a stock creature can result in a very different and distinct entity, mutation modifiers can expand the scope and variety of mutational powers, altering them slightly with bonuses or penalties. With little or no tweaking, these modifiers can also be applied to supernatural powers — such as spell-like abilities — used in games from fantasy other genres.

This publication is dedicated to providing useful information, game content, and ideas to players of modern, science fiction, and post-apocalyptic table-top and role-playing games in general and to fans of Goblinoid Games’ Mutant Future retroclone of classic Gamma World in particular. The rules contained herein are compatible with it and any others that use the “Basic” OGL/d20 RPG system.