The world has descended into anarchy as the remnants of governments bomb one another, scramble for power and generally make a mess of our once lovely planet. As a side effect of nuclear war and chemical proliferation, the populace begins to mutate, only able to stave off physical disfigurement with advanced technology. Or something like that. The story of Platinum Games' Anarchy Reigns isn't terribly important, and the premise is conveyed entirely via a long wall of text during the first loading screen.

It's all merely a backdrop for what's really important: punching things with rocket-fists.