The world has no continents and is covered by water , except for a few rocky islands and two polar caps where the ice never melts. The oceans teem with aquatic life that is consumable by most species of humanoid. Most noteworthy is the Tyranno Fin, an extremely aggressive and very large predator currently holding the claim to be the largest carnivorous fish in the known universe. Most life forms are cataloged and many are hunted, fished or harvested by the local population and sold on the Galactic market.
Nilfeheim was settled by Terrans in 2160 . A group consisting mainly of Scandinavians, Norwegians and Germans belonging to the Viking Movement and the Church of Odin left Earth so they could adhere to their chosen lifestyle, which rejected modern technology and advancements. The Nilfeheim settlers received genetic tailoring so they were better adapted to their new home world. Gills are the most noticeable change, similar to sea turtles, and allows them to remain submerged for as long as they stay warm.
Conditions on Nilfeheim were harsher than anticipated and the colony struggled to stay alive. Around 2300, the settlers, calling themselves Neo Vikings, resorted to piracy and raided civilian shipping lines and other colonies. After the formation of the United Stars of the Galaxies, a Union battleship ended the Neo Vikings short but violent history of piracy. Its Captain giving the Neo Vikings on Nilfeheim a choice: remain isolated from any contact with other worlds or join the United Stars. He also made it quite clear what would happen if they would ever resort to piracy again. The Neo Vikings decided for the second option and Nilfeheim became a member world in 2390.
Since then Nilfeheim has developed a distinct local culture that borrows heavily on historical and romantic elements of an Earth culture known as the Vikings. Their present culture focuses on the preservation and strict adherence to their ancient traditions.