Marc's home from college on break, spending his time laughing about some of the crazy news stories he's found online, and gaming. When a message appears in his line of sight, blocking out absolutely everything else, he nearly freaks out. The message warns that the world has been in a variant Natural Laws beta test for millennia and that it's about to revert to the norms.

Deciding that even if he is insane, it's not going to hurt anything to try to prepare, he settles in to do so. Despite the atrocious lack of skill the System has with the English language, he manages to work his way through enough help files to get a clue of what's coming. After sharing his discovery with a few friends, they all start to prepare together.

Once the change begins, the small group races to create a Safe Zone, an area where monsters will not spawn and where they can gather other survivors in an attempt to rescue as much of the town as possible. Along the way they discover that the new System can award classes that resemble those of the games the group has played, as well as magic for those capable of grasping it.

With monsters spawning throughout the town, everyday animals being mutated into dangerous creatures, and a System that desperately needs English language lessons, they'll do their best to save as many of the local residents as they can.