The game is set in the early 21st century after the "Greater Depression" has destroyed the global economy. Focusing on the United States, the game describes a country undergoing slow collapse. Most of the largest cities have continued to expand and formed massive metroplexes, in some cases covering entire states' worth of land. Outside of the metroplexes the majority of the country has become known as "Outlaw" where there is virtually no federal or state protection and the road network is barely maintained between the glittering lights of the Metroplexes. Scattered throughout the Outlaw and even in the darker and more forbidding areas of the Metroplexes, zones known as "Demonground" have begun to appear. Out of these areas spread monsters, everything from legendary creatures such as Vampires and Werewolves, to the science fiction nightmares of aliens and cyborgs. The PCs typically assume the roles of people who have stumbled across this "Dark Invasion" and taken up arms against it.
The first edition uses a d10 to resolve skill checks.