In this campaign world, old Norse beliefs remain powerful across Scandinavia and the lands where Norse travelers have settled. Most people know stories of the Æsir, Vanir, jötnar, land spirits, the dead, and the strange beings that live at the edges of human settlement.
The gods are not treated as ordinary nonplayer characters. They are powers behind oaths, storms, fertility, battle, poetry, death, prophecy, craft, sea travel, and household life. Their influence is usually felt through custom, omen, priestly duty, saga, sacred place, or consequence.
For D&D play, the campaign can blend Norse ideas with game cosmology, but the Norse frame should remain visible:
Religion should shape choices without forcing a single answer. Characters may make offerings, keep oaths, fear taboo places, seek omens, ask a goði for guidance, or suffer social consequences for mocking sacred obligations.