- Ho Yay: Gawain and Bertilak get to kiss a lot.
- Magnificent Bastard: The titular Green Knight primarily serves as a judge and tester of knights and is tasked to have either discredited the legendary Round Table or reveal the true nature of their honor. A powerful figure clad in verdant green armor, the Green Knight waltzes into Arthur's court and issues a challenge, using a sharp tongue and biting wit to bait even the king himself into an obvious trap, only for Gawain to behead the Green Knight in his stead. Disguised as Bertilak de Hautdesert, the Green Knight sets up hunt after hunt to secretly test Gawain and even uses his wife to test the knight's chastity. With Gawain's single flaw being his fleeting hesitance towards death, the Green Knight spares and congratulates him, ending the story as mysterious but reasonable as he began.
- Threesome Subtext: Lord Bertilak/the Lady/Gawain. (An alternate title might be "local couple hits on knight in most roundabout possible way".)
- Trope Namers: The oldest recorded use of the phrase "Knight Errant" (as "knygt erraunt") occurs here.
- Values Resonance: When Gawain initially thinks his lesson is to not trust women, the Green Knight promptly sets him straight that it was his failure that was at fault, not Lady Bertilak's.
YMMV / Sir Gawain and the Green Knight