Actors wore hockey shoulder pads underneath their viking costume to make them appear larger and fiercer.
Despite knowing that the Vikings' helmets didn't historically have large animal horns on them, the film makers decided to add them in anyway. This would work with the modern audiences who have an ingrained stereotype of what a Viking should look like in their mind. Moreover, the horns make the Vikings look more terrifying.
Both metal and rubber helmets were made. The rubber ones were used when actors did stunts. The metal ones would have injured their heads.
Dark Horse released a comic adaption of this film.
The Native Americans the Vikings encounter historically were the Beothuk people of Newfoundland in Canada. There is a large historical site around the Viking settlements in Newfoundland for tourists to visit.
The Pathfinder's house was constructed around a real tree which was found at the location and had to be reinforced. The design of the Native American huts was partly inspired by the famous opera house in Sydney, Australia.
Based on the Norwegian movie Veiviseren, also known as Ofelas (1987), where the characters are indigenous Scandinavians (Sami).