The Green Knight disrupts a feast in King Arthur’s court. The knights are enjoying a New Year’s feast and engaging in merriment when the Green Knight enters. The Green Knight proposes his game: the Green Knight will endure a blow from a knight if, in return, the knight will submit to a blow a year and a day later. The knights do not respond because they realize that the Green Knight’s game is sure to result in death. At this, the Green Knight chastises Arthur’s court for their cowardness: “Is this the court for its courage renowned” (ll. 309). Arthur defends the honor of his court by initiating an oral oath to take part in the Green Knight’s game. Before Arthur can fulfill this oath, Sir Gawain steps in and assumes Arthur’s place. In taking Arthur’s place, Gawain demonstrates loyalty to Arthur, his liege lord and assumes responsibility of the oath.
Somberly, Gawain plays the game by giving the Green Knight a blow with an axe, chopping off his head. The Green Knight, however, does not die. He simply picks up his severed head and demands that Gawain honor his pledge and meet him in the Green Chapel and submit to the blow in a year and a day.
When it is time, Gawain ventures in search of the Green Chapel. He comes upon the household of Bertilak. Here, Bertilak offers Gawain a place to rest. Gawain stays with Bertilak three days and, each day Bertilak goes hunting. Bertilak agrees to share his kill but, in return, Gawain is to give the host “what he gains” in the house each day. This proves difficult because Bertilak’s wife makes sexual advances upon Gawain. Gawain successfully resists the lady’s advances and manages to escape with merely a kiss on the first two days, which he gladly repays to his host. On the third day, however, the lady offers Gawain a green girdle which is supposed to protect Gawain from the Green Knight. Gawain’s fear causes him to take a green girdle from the lady, which he keeps hidden from Bertilak. In keeping the girdle a secret, Gawain breaks the oath with the host.
In the final scene, Gawain meets the Green Knight and is rewarded for his bravery and courage. Courageously, Gawain offers himself to the Green Knight. The Green Knight merely grazes Gawain’s neck. Here, the Green Knight reveals that he is really Bertilak (he was transformed into the Green Knight by Morgan LaFey) and the scratch is a result of Gawain’s acceptance of the green girdle. Gawain views his escape as a reminder of his own fault and weakness. Although Bertilak and King Arthur’s court all seek to congratulate Gawain, the knight remains humbled by shame. In the end, readers are to celebrate Gawain’s super-human capacity of virtue but also remember that Gawain faults because he is, after all, only human.