Hnefatafl was mentioned in several of the medieval sagas, including "Orkneyinga saga", "Friðþjófs saga", "Hervarar saga", and others. These three period treatments of Hnefatafl offer some important clues about the game, while numerous other incidental references to "Hnefatafl" or "Tafl" exist in saga literature. Sagas help indicate the widespread use of board games just by mentioning them—although rituals varied in the Viking period from region to region, there were some underlying basics to culture. The fact that the sagas mention board games indicates this use because the sagas are read and understood by a very large audience.