The anonymous fourteenth-century Middle English romance Sir Gawain and the Green Knight begins with a game, an element of play – though deadly serious, if not just plain deadly, play. A mysterious Green Visitor (“a monstruous apparition […] / one of the tallest creatures in the whole earth” [136–37]) calls at Arthur's court on New Year's Day and proposes an exchange of blows between himself and Arthur, or between himself and Arthur's stand-in:

Such an exchange of blows, playful and not, occurs in earlier Celtic literature in tales related to Cuchulainn, and some scholars have traced Gawain’s distant origins back to the Irish hero and demi-god. Later in the poem, when Gawain arrives at the castle of an overly generous host en route to his potentially fatal second encounter with the Green Knight, his host seeks to ease his worries by offering him comfort and hospitality, and a three-fold game of exchanges that leads in turn to a three-fold temptation of Gawain by the host's wife. Versions of such temptations also have analogues elsewhere in medieval literature. The anonymous author of the poem thus proves himself just as well read as well skilled in writing a romance whose oft- and rightly praised narrative progresses both linearly and with an abundance of asides. In the end, it is revealed that the entire poem has been built around a magical game, a test, devised by Morgan Le Fay: