The story of Sir Gawain and the Green Knight begins with descriptions of the great epic heroes of Troy, and goes all the way down to King Arthur's time, as a grand introduction for him and his court. King Arthur and his court are gathered for a Christmas celebration. There are festivities, and everyone sits down to have dinner. Arthur, however, refuses to have his dinner until he hears a story. A huge green giant with red eyes then comes riding into the dining hall on his green horse with a holly bob, a sign of peace, in one hand and an ax, with a very long blade, in the other. Everyone is completely amazed. After he establishes that he comes in peace, the Green Knight challenges Arthur's men to a game which consists of one player hitting the Green Knight with the ax. He will have to seek the knight out at the Green Chapel within a year and a day (magical element) to receive three hits from him with the ax. The player will also get to keep the ax. Everyone in the hall is intrigued by his color, and the knights are afraid to step forward. The Green Knight laughs because he says he has heard so many great things about Arthur's brave men and now none wish to accept his challenge. Of course, Arthur is embarrassed by all this, and he accepts. Then, Gawain humbly comes forward, saying since he would be of no great loss, he will play the game. He hits Bercilak with the ax, cutting off his head, which rolls around on the floor. Bercilak picks up his head, holds it in his arm, the eyes open and it says for Gawain to begin searching for him on All Hallow's Day. He then rides off without replacing his head. The court of King Arthur then celebrates. All Hallow's day arrives, and Gawain sets off for his adventure, while the people are secretly angry that Arthur is allowing his nephew to go on a journey that they believe he will never return from. Gawain leaves with his horse, Gringolet, and along the way, he faces many harsh conditions. He comes across serpents, wild animals, and wild men of the woods that he has to fight. He must also brave falling rocks, freezing weather and loneliness but God does protect him. Finally, it is Christmas Eve and snowing heavily. Gawain prays for some sort of shelter where he can hear mass. It is at this point that he comes to Bercilak's castle which appears magically before him. It is a beautiful, bright and green landscape, in total contrast from where he just was. He then goes to the castle where the lord, who is Bercilak, unbeknownst to Gawain, allows Gawain to stay. Bercilak, then proposes to Gawain that while Gawain is there they will exchange at night what they have won in the day. Then there are the three hunts which parallel the seduction of Gawain by Bercilak's wife.
On the first day Bercilak hunts a deer, which is considered a shy, gentle animal. Gawain behaves like a deer in response to Bercilak's wife's advances. Bercilak's wife on this day is also not too aggressive and kisses Gawain once. That night Bercilak gives Gawain the deer and Gawain gives Bercilak the kiss which he received. Next a boar is hunted which is more difficult to catch and Bercilak's wife is even more aggressive and kisses Gawain twice. Finally, on the third day Bercilak goes hunting for a fox, a sly creature and on this day his wife is also cunning. She seduces Gawain more than before and gets him to take a girdle, which is a belt, that she says will protect him because it is magical and says for him not to tell her husband. She is of course lying but Gawain takes the girdle and agrees. She also kisses him three times. There are three reasons why Gawain does not take advantage of the situation with Bercilak's wife. The first is because she is the host's wife. Next if Gawain sleeps with her then he will have to exchange with Bercilak what he has received and finally Gawain thinks he is going to die and does not want to commit adultery which is a sin and then have to face God. That night Gawain is given the fox from Bercilak and he gives Bercilak three kisses but not the belt. Gawain is now ready to leave to find the Green Chapel, the home of the Green Knight. Bercilak directs Gawain to the area of a burial ground which Gawain thinks is the Green Chapel. Bercilak then goes there to give Gawain his three hits. The first and second swings of the ax do not touch Gawain but the third cuts his neck. At this point Gawain learns from Bercilak the truth about all that has taken place. Bercilak tells him that he did not hit him the first and second time because Gawain passed the first and second tests of presenting what he won that day to Bercilak. On the third day, however, Gawain did not give Bercilak the green girdle and so he cut him on the third swing. Gawain failed on the third day by lying to Bercilak. Gawain learns here that Bercilak is the Green Knight, the lord's home he was staying at and that he put his wife up to seducing Gawain. He goes on further to explain that Morgan Le Fay, Arthur's half sister, is the one who devised this test for Arthur's court. Gawain then takes the girdle and wears it as a symbol to remember his weakness. He returns home to Arthur's court where everyone is glad to see him. Gawain tells of his adventure and is wiser unlike the people he returns back home too, who turn his girdle into a fashion statement.