What follows is a guest post from the Good Doctor himself. For a Stoopid American, he sure knows a lot about English literature!

The Gawain doctor is in—and like most doctors, he’s running a little behind.
I should probably start with the patient’s question, which was about how faithful Sir Gawain and the Green Knight is to the 14th-Century poem of the same name. It’s not particularly faithful, but since we’re not 14th-Century readers, that’s not necessarily a bad thing. It is deeply engaged with the original poem in ways that are probably more interesting than would be the case in a more direct adaptation. Knowing the poem will give you a framework and additional material to think about, but it won’t “explain” the film or leave you with nothing to do but listen to some English professor carping about what the director misunderstood or didn’t get right.
The original poem explores the themes of courtesy and mirth, reflecting on how a society genuinely inspired by the medieval Christian understanding of those virtues might operate (and on how the actual medieval world falls short). David Lowery’s movie has almost no mirth, and courtesy always turns out to be a deceptive mask (as it sometimes is in the original as well). It feels more like the world of Beowulf or Game of Thrones than the refined and civilized world of the movie’s source material.
Fittingly, Lowery’s Sir Gawain is a flawed everyman rather than an innocent embodiment of courtesy. He has a hooker-with-a-heart-of-gold girlfriend, and his drunken excess is always set in a brothel or a tavern to distinguish it from the equally-inebriated, Christian-sanctioned mirth of the original poem. I think this revision is probably designed to make Gawain a relatable character, allowing modern film-goers to identify with his trials and tribulations over the course of the film, in much the way that medieval readers were invited to identify with the courteous but inexperienced Gawain of the poem.
At the same time, Lowery nicely captures the sense in the original poem that things are rarely as simple as they seem, and that forces at the edge of our understanding—if not entirely beyond it—are at work shaping the course of events and giving them meaning. His approach is more in the form of a fever dream than the subtle and teasing allegorical undertone of the original poem, but it feels properly medieval in its rejection of naturalist or realistic plot in favor of symbolic or allegorical meaning.
There are definitely easter eggs for readers of the original poem. There is a brief mention of the five virtues, an important set piece from the original poem in which Sir Gawain’s shield is allegorized for its “endless knot” pentangle front and painting of Mary inside. When that shield is cracked and destroyed in the opening episode of his journey, it confirms what you had probably already guessed about how far those medieval virtues would get you in the movie’s world.
The film also follows the basic structure of the original poem: the Green Knight’s visit to Arthur’s court, fast-forwarding to Gawain’s departure a year later, a Christmas over-nighter at a mysterious castle, and a final conclusion of Sir Gawain’s “game” with the Green Knight. Readers familiar with the poem will find significant resonances with the critically important castle episode immediately prior to that final encounter, and may be particularly interested in the decision to cast the same actress as the hooker-with-the-heart-of-gold and the lady of the house.
The final confrontation with the Green Knight is as confusing and counter-intuitive as in the original, but works to a different end. My own reading is that, where the original invites the recognition of our fallen nature in even the most virtuous of Christian heroes, Lowery is more interested in revealing the systemic injustice of patriarchy. Ironically, Lowery’s Gawain must pass his test if he is to succeed, whereas the 14th-Century Gawain can become a hero despite his all-too-human failings. But there is plenty of material (friendly robbers, lady ghosts, talking foxes, earth giants) to fuel other interpretations, which is one of the things that makes this movie so rewarding.
If you can figure out what those creepy giants are up to, you’re a smarter reader than I am. Len tells me that they’re Czechoslovakian anime, and who am I to disagree?