Rifts® Atlantis is an alien civilization transplanted to Earth.

It is a multi-dimensional kingdom inhabited by monstrous aliens dominated by the Splugorth. Ley lines are tapped by giant, mystic pyramids. Anything and anybody can be bought or sold at the Dimensional Market at Splynn, while the city of Dragcona serves as a haven for dragons and supernatural beings. Located in the southern mountains is the Gargoyle Kingdom and to the north is the Valley of Wonders. Alien creatures lay claim to the land and others are sold at the trans-dimensional slave markets.

The Splugorth and their minions are described, complete with attributes and full statistics. They include the High Lords, Conservators (bio-borg), Overlords, Powerlords, Slavers, Sunaj Assassins and others. There are new magic O.C.C.s, new player character races, ancient Atlanteans, bio-wizardry, and much more.