Raiders of the Serpent Sea is an epic adventure book published by Arcanum Worlds for the 5th Edition of the world's greatest roleplaying game.

In the nearly forgotten long ago, the survivors of a vanquished civilization fled the cruel giants and demons devastating their home world. In desperation, the heroes of that time unleashed primal magics to create a safe haven for those they protected. They ushered the last of the mortals through a portal into this new world.

Covered in dark forests, ruled by sinister monstrosities, and with a storm-tossed sea connecting the many disjointed islands, this new world, Grimnir, is full of dangers. To survive, the people, now known as raiders, learned to sail that serpent filled sea, learned to survive in this impossible world. They sail with pride... and the strongest take what they need from both the land and any foolish enough to stand in their way.