If you're the kind of role-playing gamer who attempts to have sexual intercourse with every random NPC you come across, then 'Your Highness' was made specifically for you. This is the multi-million-dollar physical representation of a late night Dungeons and Dragons game with friends, one that's gone way past the point of anyone taking it seriously and sinking into that kind of "Who cares?" anarchy that happens when you're up way past your bedtime. You'll have to bring your own 20-sided die, but director / Dungeon Master David Gordon Green provides the rest.
There's a very specific kind of vibe that Green is attempting here -- it's loose, ribald, silly, and no one really seems to care how it all turns out in the end, but the film also wants to show respect to the sword-and-sorcery genre. The balance is such that the action sequences are meticulously staged to hold their own with any sword-clanging B-picture, while the comedy is so off-the-cuff that it's almost immediately forgettable. It doesn't help that there's basically only one kind of joke in 'Your Highness,' and the novelty of hearing co-writer and star Danny McBride utter anachronistic F-bombs is only slightly amusing the first time. By the 20th time, it's downright grating.
The whole movie comes off like a bunch of people futzing around with a big wad of studio money and no real purpose (I'd plant 'Your Highness' squarely between the somewhat better 'Land of the Lost' and the slightly worse 'Year One' in that regard). It's a knights-on-a-quest-to-rescue-a-maiden movie, with everyone doing their own approximation of a British accent, tossing out an occasional, tired drug reference (just smoking the stuff isn't really a joke, guys -- write something funny around it), and just generally goofing around in fancy costumes. It's affable enough to never bore you, but not nearly funny enough to mean anything.
McBride can carry his own material, but, here in his first leading man role, he misses the mark. He play-acts instead of acting and does himself a disservice as a writer by not writing anything approaching wit. High comedy here is seeing McBride and James Franco (as his brother) watch Natalie Portman undress to a thong or watching Justin Theroux (as an evil wizard with Wolverine hair) serve a platter of fish sticks to his kidnapped bride-to-be (Zooey Deschanel, wasted). Franco (also wasted, but in a different way) seems to be having the most fun, with an infuriatingly lazy approach, as if he's laughing at you for watching the film or Universal for paying for it.
Green doesn't seem to care one bit when his actors are interacting, but for some inexplicable reason, he decides to direct all of the big effects scenes and action beats with the utmost care. They work, displaying an assured rhythm that Green was still working out in 'Pineapple Express.' Why are those scenes stuck smack dab in the middle of such a dumb comedy? They end up feeling out-of-place here, and they also draw unneeded attention to the fact that the comedy half of the story is so hopelessly, weakly immature.
Sure, there's a place in the world for immature comedies, but it's all the about the hit-to-miss ratio of outlandish gags. 'Your Highness' misses way more than it hits. We could ignore the lack of laughs and celebrate that the R-rated fantasy film is alive and well at the heart of 'Your Highness,' but it feels a little disingenuous for such a lark. If Green wanted to make an awesome fantasy film, he should have, and if he wanted to make a great stoner comedy, well, he already did once.