The characteristics of a medieval romance include chivalry, a knight's brave actions, a high esteem for women, a fairy-tale setting, a simple plot, a quest for love, and supernatural elements, such as wizards, witches, and dragons. 

Sir Gawain and the Green Knight, which was written in the late fourteenth century, is a good example of the characteristics of a medieval romance. First, it features King Arthur and the knights of the round table. King Arthur and his knights followed a code of chivalry, which included having honor, bravery, loyalty, and gentlemanly manners. It also included committing acts of selflessness for the benefit of others.

Sir Gawain and the Green Knight fits the characteristics of a heroic knight as the protagonist in a medieval romance. Gawain is challenged by a mysterious green knight to cut his head off with a splendid looking ax. He does this with the understanding that the green knight will return in one year and one day to do the same to Gawain. Gawain beheads the knight in one stroke, showing bravery and courage. Supernaturally, the green knight does not die, and he picks up his head and promises to return.  

Later, Gawain sets off on a quest to find the green chapel so that he can fulfill his side of the bargain. This shows his honor, as he is keeping his word even unto death. It also shows his bravery by allowing the green knight to behead him. These are two characteristics of a medieval romance.

On his journey, he meets  Bertilak de Hautdesert, the owner of a beautiful castle, and his wife. Lady Bertilak tries to seduce Gawain, but he refuses her advances and acts honorably toward her, being careful not to offend her, thus displaying a chivalrous attitude. 

When Gawain meets the green knight, he submits to the beheading, but the green knight only causes a scratch on his neck. Then he reveals that he is really Bertilak and has been transformed by magic. This is another characteristic of a medieval romance—supernatural elements. Bertilak tells Gawain that the whole thing was a trick, set up by the sorceress Morgan Le Fay, to test King Arthur's knights. Gawain is afraid he failed the test, but Bertilak assures him that he conducted himself admirably.

A medieval romance is a literary genre that developed in the Middle Ages, albeit closely following such antecedents as the ancient epic and the late antique novel (such as the works of Apuleius and Longus). Romances can be written in prose or verse, with the prose ones tending more towards fictionalized history and the verse ones towards pure fiction. They tell the stories of aristocrats engaged in feuds, love relationships, and quests. The romances draw their materials from a range of historical or quasi-historical sources, including the courts of Charlemagne and King Arthur and traditional stories such as those of Tristan. Supernatural and fantastic settings and events are common.

Sir Gawain and the Green Knight is typical of the genre in many ways. It was written during the medieval period. The protagonist is a knight in the Arthurian court. He embarks on a quest. The quest has many supernatural and fantastic elements. It has a theme of chivalry and the appropriate forms of ethics and courtesy expected of a knight. It includes elements of both the masculine heroic journey and romance in the sense of relationships between men and women.

Medieval Romances typically exhibit the following characteristics:

-Arthurian tales which deal with the quests and challenges of Arthur and his knights.

-Tells a story of a single knight and a single quest.

-The story exists within the constraints similar to a fairy-tale.

-The story contains elements of courtly love- Courtly love is the relationship between a knight and his lord's lady. The knight is required to love and respect the lady within the same way which he loves and respects his lord. The love the knight holds for the lady is fueled by his desire to please her and, therefore, to be worthy of her love and/or to win her favor.

-Typically, the knight must face the challenge of maintaining a balance between chivalry and love.

Based upon these characteristics, Sir Gawain and the Green Knight contains many of the elements to be considered a Medieval Romance.

First, the story deals with one knight, Sir Gawain, and a single quest. Gawain promises to meet the Green Knight one year from their initial meeting to receive a blow from the Green Knight in exchange for the one Gawain gave to him.

Second, the story contains elements which includes fairy-tale like aspects. The Green Knight is mystical. The fact that he was able to lose his head and stay alive alludes to a supernatural element seen in typical fairy-tales.

Third, the story contains elements of courtly love. Gawain must show both Lady Bertalik and Guinevere courtly love. As charged by his position as a knight to Arthur, Gawain must show Guinevere love and respect. In the same way, given Gawain is sheltered at Bertalik's, he must show Lady Bertalik the same kind of respect and love.

Lastly, Gawain greatest challenge is finding a balance between chilvarly and romantic love for Lady Bertalik.