The world of Sir Gawain and the Green Knight is governed by well-defined codes of behavior. The code of chivalry, in particular, shapes the values and actions of Sir Gawain and other characters in the poem. The ideals of chivalry derive from the Christian concept of morality, and the proponents of chivalry seek to promote spiritual ideals in a spiritually fallen world.

The ideals of Christian morality and knightly chivalry are brought together in Gawain’s symbolic shield. The pentangle represents the five virtues of knights: friendship, generosity, chastity, courtesy, and piety. Gawain’s adherence to these virtues is tested throughout the poem, but the poem examines more than Gawain’s personal virtue; it asks whether heavenly virtue can operate in a fallen world. What is really being tested in Sir Gawain and the Green Knight might be the chivalric system itself, symbolized by Camelot.

Arthur’s court depends heavily on the code of chivalry, and Sir Gawain and the Green Knight gently criticizes the fact that chivalry values appearance and symbols over truth. Arthur is introduced to us as the “most courteous of all,” indicating that people are ranked in this court according to their mastery of a certain code of behavior and good manners. When the Green Knight challenges the court, he mocks them for being so afraid of mere words, suggesting that words and appearances hold too much power over the company. The members of the court never reveal their true feelings, instead choosing to seem beautiful, courteous, and fair-spoken.

On his quest for the Green Chapel, Gawain travels from Camelot into the wilderness. In the forest, Gawain must abandon the codes of chivalry and admit that his animal nature requires him to seek physical comfort in order to survive. Once he prays for help, he is rewarded by the appearance of a castle. The inhabitants of Bertilak’s castle teach Gawain about a kind of chivalry that is more firmly based in truth and reality than that of Arthur’s court. These people are connected to nature, as their hunting and even the way the servants greet Gawain by kneeling on the “naked earth” symbolize (818). As opposed to the courtiers at Camelot, who celebrate in Part 1 with no understanding of how removed they are from the natural world, Bertilak’s courtiers joke self-consciously about how excessively lavish their feast is (889–890).

The poem does not by any means suggest that the codes of chivalry be abandoned. Gawain’s adherence to them is what keeps him from sleeping with his host’s wife. The lesson Gawain learns as a result of the Green Knight’s challenge is that, at a basic level, he is just a physical being who is concerned above all else with his own life. Chivalry provides a valuable set of ideals toward which to strive, but a person must above all remain conscious of his or her own mortality and weakness. Gawain’s time in the wilderness, his flinching at the Green Knight’s axe, and his acceptance of the lady’s offering of the green girdle teach him that though he may be the most chivalrous knight in the land, he is nevertheless human and capable of error.

Though the Green Knight refers to his challenge as a “game,” he uses the language of the law to bind Gawain into an agreement with him. He repeatedly uses the word “covenant,” meaning a set of laws, a word that evokes the two covenants represented by the Old and the New Testaments. The Old Testament details the covenant made between God and the people of Israel through Abraham, but the New Testament replaces the old covenant with a new covenant between Christ and his followers. In 2 Corinthians 3:6, Paul writes that Christ has “a new covenant, not of letter but of spirit; for the letter kills, but the Spirit gives life.” The “letter” to which Paul refers here is the legal system of the Old Testament. From this statement comes the Christian belief that the literal enforcement of the law is less important than serving its spirit, a spirit tempered by mercy.

Throughout most of the poem, the covenant between Gawain and the Green Knight evokes the literal kind of legal enforcement that medieval Europeans might have associated with the Old Testament. The Green Knight at first seems concerned solely with the letter of the law. Even though he has tricked Gawain into their covenant, he expects Gawain to follow through on the agreement. And Gawain, though he knows that following the letter of the law means death, is determined to see his agreement through to the end because he sees this as his knightly duty.

At the poem’s end, the covenant takes on a new meaning and resembles the less literal, more merciful New Testament covenant between Christ and his Church. In a decidedly Christian gesture, the Green Knight, who is actually Gawain’s host, Bertilak, absolves Gawain because Gawain has confessed his faults. To remind Gawain of his weakness, the Green Knight gives him a penance, in the form of the wound on his neck and the girdle. The Green Knight punishes Gawain for breaking his covenant to share all his winnings with his host, but he does not follow to the letter his covenant to decapitate Gawain. Instead of chopping Gawain’s head off, Bertilak calls it his right to spare Gawain and only nicks his neck.

Ultimately, Gawain clings to the letter of the law. He cannot accept his sin and absolve himself of it the way Bertilak has, and he continues to do penance by wearing the girdle for the rest of his life. The Green Knight transforms his literal covenant by offering Gawain justice tempered with mercy, but the letter of the law still threatens in the story’s background, and in Gawain’s own psyche.

At the beginning of Parts 2 and 4, the poet describes the changing of the seasons. The seasonal imagery in Part 2 precedes Gawain’s departure from Camelot, and in Part 4 his departure from the host’s castle. In both cases, the changing seasons correspond to Gawain’s changing psychological state, from cheerfulness (pleasant weather) to bleakness (the winter). But the five changing seasons also correspond to the five ages of man (birth/infancy, youth, adulthood, middle age, and old age/death), as well as to the cycles of fertility and decay that govern all creatures in the natural world. The emphasis on the cyclical nature of the seasons contrasts with and provides a different understanding of the passage of time from the more linear narrative of history that frames the poem.

When the poem opens, Arthur’s court is engaged in feast-time customs, and Arthur almost seems to elicit the Green Knight’s entrance by requesting that someone tell him a tale. When the Green Knight first enters, the courtiers think that his appearance signals a game of some sort. The Green Knight’s challenge, the host’s later challenge, and the wordplay that takes place between Gawain and the lady are all presented as games. The relationship between games and tests is explored because games are forms of social behavior, while tests provide a measure of an individual’s inner worth.

According to the Gawain-poet, King Solomon originally designed the five-pointed star as his own magic seal. A symbol of truth, the star has five points that link and lock with each other, forming what is called the endless knot. Each line of the pentangle passes over one line and under one line, and joins the other two lines at its ends. The pentangle symbolizes the virtues to which Gawain aspires: to be faultless in his five senses; never to fail in his five fingers; to be faithful to the five wounds that Christ received on the cross; to be strengthened by the five joys that the Virgin Mary had in Jesus (the Annunciation, Nativity, Resurrection, Ascension, and Assumption); and to possess brotherly love, courtesy, piety, and chastity. The side of the shield facing Gawain contains an image of the Virgin Mary to make sure that Gawain never loses heart.

The meaning of the host’s wife’s girdle changes over the course of the narrative. It is made out of green silk and embroidered with gold thread, colors that link it to the Green Knight. She claims it possesses the power to keep its wearer from harm, but we find out in Part 4 that the girdle has no magical properties. After the Green Knight reveals his identity as the host, Gawain curses the girdle as representing cowardice and an excessive love of mortal life. He wears it from then on as a badge of his sinfulness. To show their support, Arthur and his followers wear green silk baldrics that look just like Gawain’s girdle.