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.