"'Now if you are truly as bold as the people all say, / You will grant me gladly the little game that I ask...'" (lines 53-54).
"'Come to the Green Chapel, I charge you, and take / A stroke the same as you've given, for well you deserve / To be readily requited on New Year's morn'" (lines 175-177).
"After riding through wild country and encountering many dangers, he comes upon a splendid castle" (237).
King Arthur and his knights are at a feast when the Green Knight, an intimidating stranger, enters. The Knight presents a challenge to Arthur and his knights in which one of them may strike him with an ax and he will return the hit later.
"' Little as it is, it seems less in value, / But he who knew what charms are woven within it / Might place a better price on it, perchance'" (lines 220-222).
King Arthur accepts the Green Knight's challenge, but Sir Gawain, one of Arthur's knights, requests to be the one who takes part in the game. Gawain strikes the Green Knight and beheads him. However, the Knight still lives, and, before riding off, he urges Gawain to uphold their bargain so he can repay the favor.
"'No more strokes, my friend; you've had your swing! / I've stood one swipe of your ax without resistance; / If you offer me any more, I'll repay you at once...'" (lines 302-304).
At the end of the year, Sir Gawain begins to make the journey to find the Green Knight. Along the way, he stays with a lord and lady who dwell in a castle. The lord agrees to share the food he hunts with him if Gawain promises to exchange everything he daily wins in return.
"' I consider you polished as white and as perfectly clean / As if you had never fallen since first you were born'" (lines 370-371).
The lord's wife tries to seduce Gawain and wants to give him many lavish gifts, but Gawain refuses her offers. At last, she begs him to take her green sash, and he resists until she tells him the wearer of the sash is unable to be killed. He then agrees to take it because he believes it could be helpful when he meets the Green Knight. He does not tell the lord about it.
Finally, Sir Gawain encounters the Green Knight, and the Green Knight is prepared to give his end of the challenge. After first taunting Gawain's bravery, the Green Knight proceeds to strike him with his ax. However, because Gawain wore the green sash, he was unharmed.
At this point, the Green Knight reveals that he is testing Sir Gawain and that he was actually the lord from the castle. Gawain remained loyal and chivalrous in the test except for taking the sash from his wife. Gawain deeply expresses his regret for his error, and the Green Knight says that by admitting his fault, he has cleaned himself from sin. Gawain is then able to return to Camelot.