In Volume 1, Book 3, Chapter 7, Gawaine's refusal to have mercy on a knight who killed his hounds leads him to accidentally behead the man's lover. This scene, laced with situational irony, foreshadows Gawaine's eventual role in the civil war that destroys the knights of the Round Table:
‘Thou shalt die,’ said Sir Gawain, ‘for slaying of my hounds.’
‘I will make amends,’ said the knight, ‘unto my power.’
Sir Gawain would no mercy have but unlaced his helm to have stricken off his head. Right so came his lady out of a chamber and fell over him, and so he smote off her head by misadventure.
‘Alas,’ said Gaheris, ‘that is foul and shamefully done, that shame shall never from you; also ye should give mercy unto them that ask mercy, for a knight without mercy is without worship.’
In Volume 1, Book 7, Chapter 11, Linet marvels that Beaumains has continued to put up with her berating remarks the entire time they have been traveling together. Beaumains explains the situational irony:
Unlock with LitCharts A+[T]he more ye said the more ye angered me, and my wrath I wreaked upon them that I had ado withal. And therefore all the missaying that ye missaid me furthered me in my battle, and caused me to think to show and prove myself at the end what I was[...]
An instance of both dramatic irony and situational irony occurs in Volume 1, Book 8, Chapter 24. The queen has given Dame Bragwaine and Gouvernail a love potion for La Beale Isoud to share with King Mark, but La Beale Isoud and Tristram unwittingly share it:
Unlock with LitCharts A+And then anon Sir Tristram took the sea, and La Beale Isoud; and when they were in their cabin, it happed so that they were thirsty, and they saw a little flacket of gold stand by them, and it seemed by the colour and the taste that it was noble wine.
Then Sir Tristram took the flacket in his hand, and said, ‘Madam Isoud, here is the best drink that ever ye drank, that Dame Bragwaine, your maiden, and Gouvernail, my servant, have kept for themself.’
In Volume 2, Book 17, Chapter 16, Launcelot wakes up after finding the Sangreal and being knocked out for 24 days for trying to get too close to it. There is situational irony in the revelation of where he has been this whole time:
Unlock with LitCharts A+‘Forsooth,’ said he, ‘I am whole of body, thanked be Our Lord; therefore, sirs, for God’s love tell me where I am.’
Then said they all that he was in the Castle of Carbonek.
Therewith came a gentlewoman and brought him a shirt of small linen cloth, but he changed not there, but took the hair to him again. ‘Sir,’ said they, ‘the quest of the Sangrail is achieved now right in you, that never shall ye see of the Sangrail no more than ye have seen.’