‘Your Highness’ may play in high society

The conversation probably went something like this:

David Gordon Green: “I really enjoyed directing ‘Pineapple Express.’ It was so different from the rest of my miniature, character-driven dramas that no one ever went to see. I made some nice scratch on that movie. And it had car chases in it!”

Danny McBride: “You wanna go even bigger? Why not remake ‘Pineapple Express’ in a medieval setting with monsters and wizards and Natalie Portman in a skimpy bikini?”

Green: “Oh, man, that sounds totally awesome. If only someone would write a script like that!”

McBride: “Actually, I happen to have one right here.”

And so we have “Your Highness,” which stars McBride as Thadeous, the lazy, pothead prince who lives under the perpetual shadow of his intrepid, handsome brother Fabious (James Franco).

Fabious returns home after his latest expedition with the severed head of a cyclops and a fiancee, Belladonna (Zooey Deschanel).

Thadeous is resigned to being the less favorite of his king father’s sons and is content to sit around and get high. But after the virginal Belladonna is kidnapped by the evil Leezar (Justin Theroux), Fabious beseeches Thadeous to help him rescue the fair maiden.

Much adventuring ensues, but the laughs are anemic, the plotting is haphazard and the big action set pieces are reminiscent of the “Star Wars” movies (the three bad ones).

Franco is at his most charismatic as the valiant warrior, and Portman, when she finally shows up, displays a newfound athleticism and rock-hard body – the results of her rigorous ballet training for “Black Swan.”

There are occasional funny bits, such as a visit to the home of a Yoda-like sage who demands sexual favors before providing answers, and there’s a running gag that never gets old involving the severed penis of a minotaur.

But “Your Highness,” which often feels as if it was written under the influence, has no narrative momentum – the story dawdles in fits and starts – and McBride, usually effective in supporting roles, simply isn’t leading-man material.

The film will probably play a lot better in dorm rooms with plenty of beer kegs and bongs on hand, but in the confines of a movie theater, it’s deadly – the sort of bad comedy Mel Brooks made late in his career, until he finally smartened up and quit.