The earliest known story to feature a beheading game is the 8th-century Middle Irish tale Bricriu's Feast. This story parallels Gawain in that, like the Green Knight, Cú Chulainn's antagonist feints three blows with the axe before letting his target depart without injury. A beheading exchange also appears in the late 12th-century Life of Caradoc, a Middle French narrative embedded in the anonymous First Continuation of Chrétien de Troyes' Perceval, the Story of the Grail. A notable difference in this story is that Caradoc's challenger is his father in disguise, come to test his honour. Lancelot is given a beheading challenge in the early 13th-century Perlesvaus, in which a knight begs him to chop off his head or else put his own in jeopardy. Lancelot reluctantly cuts it off, agreeing to come to the same place in a year to put his head in the same danger. When Lancelot arrives, the people of the town celebrate and announce that they have finally found a true knight, because many others had failed this test of chivalry.
The stories The Girl with the Mule (alternately titled The Mule Without a Bridle) and Hunbaut feature Gawain in beheading game situations. In Hunbaut, Gawain cuts off a man's head and, before he can replace it, removes the magic cloak keeping the man alive, thus killing him. Several stories tell of knights who struggle to stave off the advances of voluptuous women sent by their lords as a test; these stories include Yder, the Lancelot-Grail, Hunbaut, and The Knight of the Sword. The last two involve Gawain specifically. Usually the temptress is the daughter or wife of a lord to whom the knight owes respect, and the knight is tested to see whether or not he will remain chaste in trying circumstances.
In the first branch of the medieval Welsh collection of tales known as the Mabinogion, Pwyll exchanges places for a year with Arawn, the lord of Annwn (the Otherworld). Despite having his appearance changed to resemble Arawn exactly, Pwyll does not have sexual relations with Arawn's wife during this time, thus establishing a lasting friendship between the two men. This story may, then, provide a background Gawain's attempts to resist to the wife of the Green Knight; thus, the story of Sir Gawain and the Green Knight may be seen as a tale which combines elements of the Celtic beheading game and seduction test stories. Additionally, in both stories a year passes before the completion of the conclusion of the challenge or exchange is complete. Some scholars disagree with this interpretation, however, as Arawn seems to have accepted the notion that Pwyll may reciprocate with his wife, making it less of a "seduction test" per se, as seduction tests typically involve a Lord and Lady conspiring to seduce a knight, seemingly against the wishes of the Lord.
After the writing of Sir Gawain and the Green Knight, several similar stories followed. The Greene Knight (15th–17th century) is a rhymed retelling of nearly the same tale. In it, the plot is simplified, motives are more fully explained, and some names are changed. Another story, The Turke and Gowin (15th century), begins with a Turk entering Arthur's court and asking, "Is there any will, as a brother, To give a buffett and take another?" At the end of this poem the Turk, rather than buffeting Gawain back, asks the knight to cut off his head, which Gawain does. The Turk then praises Gawain and showers him with gifts. The Carle of Carlisle (17th century) also resembles Gawain in a scene in which the Carle (Churl), a lord, takes Sir Gawain to a chamber where two swords are hanging and orders Gawain to cut off his head or suffer his own to be cut off. Gawain obliges and strikes, but the Carle rises, laughing and unharmed. Unlike the Gawain poem, no return blow is demanded or given. Other oral versions of the story suggest that Sir Gawain was the Green Knight, with more characters introduced such as Chief Eagle Eye.