The story barely qualifies as clothesline: Thadeous (McBride) and Fabious (James Franco) are brothers, the former lazy, the latter heroic. When Fabious' bride-to-be Belladonna (Zooey Deschanel) is kidnapped by the lecherous wizard Leezar (Justin Theroux) on the wedding day, the boys' father King Tallious (Charles Dance) orders them both to quest to rescue her. Along the way, a few side plots involving Fabious' trusted right-hand man Boremont (Damian Lewis), a mythical unicorn-based sword, and the beautiful, revenge-hungry archer Isabel (Natalie Portman) are also lazily lobbed at the screen.

The use of language and weed jokes as the backbone for Your Highness is not surprising, but it is disappointing how the film has nothing else on its mind. There seems to be plenty of fish-out-of-water ad-libbing potential here in Green's wonderfully realized fantasy world, which looks phenomenal, yet McBride and company rarely capitalize on any of it. From start to finish, the movie is an increasingly tiresome parade of predictable anachronisms and crude sexual humor that reflects its improvised nature. The film plods along without any comedic chemistry between McBride and Franco; it seems like a role reversal might've provided a bit more comic punch (Franco is much funnier when he's smarmy), while it squanders the potential in ideas like Belladonna's lack of social skills (she's been locked in a tower her whole life).

The film's one sorta-saving grace is Portman, who pops on screen and invests so much more into the movie's silly premise than two movies deserve, selling the jokes by playing it straight. In these kinds of comedies, a relaxed, "anything goes" attitude is expected, but Portman's performance easily puts McBride and even Franco to shame, rendering McBride's lack of investment in his own movie kind of embarrassing. Not surprisingly, she also fails to generate much chemistry with her castmates, making the apparently inevitable romance between Isabel and Thadeous even more unbelievable than it already is. Deschanel might've added as much as Portman, but like her character's backstory, the actress is squandered in a role that's mostly about cleavage, while Justin Theroux looks and acts as creepy as possible.

Universal has made several high-profile bombs in the last few years, some deserving and some not, and sadly, Your Highness may continue the tradition. Again, the vivid sets, cinematography, and CGI that went into creating a fantasy universe is impressive, trumping films like Season of the Witch in scope and scale. Sadly, the lack of script and planning that went into making this a funny movie rather than a spectacle is evident, and the hazy comic focus results in the film pounding a few base notes over and over. Pineapple Express and Your Highness, paired together, form the spectrum of the stoner comedy: they illustrate the difference between a funny film about weed, and a film made under the influence of it.