Attack of the Mutant Rules System is heavily influenced by the Amber Diceless RPG, but is focused exclusively on superhero action. Character creation uses a "point buy" system that allows players to allocate (usually) 50 points among attributes, pseudo-attributes (if any), and powers. Negative score can be allocated to attributes to boost something else (for example, a -20 score could be taken in strength so that 70 points would then be available). Attributes range from -30 to +100.
Pseudo-attributes include things such as appearance, wealth, perception, and luck. Pseudo-attributes range from -5 to +10.
Powers are purchased for one point, when they are considered latent and undeveloped. They can then be increased by purchase or through play.