Richardson High School alum David Gordon Green’s (All The Real Girls, Pineapple Express) newest film, Your Highness, is a raucous, romping, bawdy update of The Princess Bride, a medieval spoof written and starring — and basically powered by — Danny McBride.

McBride plays Thadeous, a whiny, wimpy prince and the younger brother of the heroic Fabious (James Franco). The comedy duo is predictable, but effective. McBride is an overwrought child, afraid of battle and unskilled with the sword (literally and metaphorically). When spurned by his father’s displeasure or the honor bestowed upon his brother, Fabious retreats to the comfort of his androgynous, ambiguously gay friend Courtney (Rasmus Hardiker) and an unnamed, creepy-looking medieval version of a pothead. The comic conceit here is simple: impish, pampered modern male lost and out of place in a machismo fictional Dark Ages where men quest, feast, and seek honor of battle.

Your Highness needs a central conflict, and that comes via the introduction of Leezar (Justin Theroux) a wizard-demon seemingly spoofing the 1980s fantasy villains featured in movies like Labyrinth. Leezar’s modus operandi is to fulfill a 100-year-old prophesy that states that anyone who has sex with a virgin princess on the night when this fictional world’s two moons eclipse will sire a dragon baby so powerful it will aid the father’s efforts to take over the world. This ritual, following the foul-mouthed logic of 90 percent of Your Highness’ humor, is called “The F**kening.” If that phrase feels offensive to you, give up reading now. This movie is not for you. If that made you giggle, then you’ll love Your Highness.

That audience split is Your Highness’ bane and virtue. The film takes advantage of what seems to be an ever-expanding appetite for adolescent-minded sex humor. Nearly all the movie’s jokes follow two formulas: an over-the-line, sort of unexpectedly graphic sexual innuendo or a casually dropped f-bomb or some other explicative. McBride and Green set up a plastic, hyper-formal, stylized medieval world and then cut through it with swearing and sex jokes. To their credit, it is a model that proves remarkably effective for a great majority of the movie, though its predictability wears thin.

Filling in the gaps between the off-handed “oh s**t’s,” and “oh farts,” is a creatively ridiculous quest scenario. Thadeous and Fabious set off to find and kill Leezar who has stolen Fabious’s bride-to-be, Belladonna (Zooey Deschanel) a virginal princess whom Fabious picked up in a lonely tower where she had been imprisoned by Leezar since birth.

Deschanel provides one of my favorite moments in the movie early on, when, at a banquet the night before she is re-stolen by Leezar, Belladonna picks up her food with her hands, clumsily shoving it into her mouth. Fabious explains that living in the tower for so long has made her unaccustomed to many of the habits of the outside world, while Thadeous mutters and swears under his breath, insulting the poor girl. It is a moment that represents Your Highness’s brand of humor at its best, drawing out the untied ends of fairy tale logic to its farthest conclusion and then showering them with puerile disdain and snobbish scoffing. This smart, historically-minded humor makes Your Highness feel at times like it was written by British comedian Eddie Izzard.

Once Belladonna is captured, the boys must rescue her, which means coming into contact with a stoned, child molesting wizard/lizard, a dough-boy bad guy who rules over a kingdom of naked women, insurrection from the jealous and ambiguously gay knights that accompany the princes on their journey (all the males in this movie may or may not have homosexual tendencies), and finally gaining the companionship of Isabel (Natalie Portman), a skilled female assassin who is also out questing.

Green does well to keep McBride’s script moving, if that skipping, unselfconscious direction does turn Your Highness into a monotonous, regularly-timed litany of similarly themed jokes. The movie never wastes time over-explaining things, needlessly developing characters, introducing emotions or passions other than faux-romance or brute lust, or trying to make the film work on any level but the visceral. It is an irreverent, obscene thing whose great comedic punch line comes in the form of animal penis hung around a character’s neck. That kind of stuff will make Your Highness an audience favorite, winning rotation on college DVD players and midnight screenings. But the movie’s one dimensionality will also prevent it from ever sitting in the court of more comedically intelligent medieval send-offs, such as The Princess Bride, Monty Python and the Holy Grail, or The Black Adder.