“Blades of Glory” could have been awesome. The potential is all there—figure skating is ripe for lampooning, and putting Will Ferrell, a big, lumbering comedic oaf, out on the ice is a no-brainer. But “Blades” winds up being duller than a pair of rusty skates. Farrell does his best, as does the rest of the supporting cast, but the ultimately tepid script forces the film to play it safe instead of going for the comedic triple axel it could very well have pulled off.

Farrell stars as Chazz Michael Michaels, a “lone-wolf” figure skater who eschews elegance and grace for crotch-pumping improvisation and pyrotechnics. His nemesis is Jimmy MacElroy (Jon Heder), a hygiene-obsessed effeminate skating prodigy whose prowess on the ice is unmatched, if unimaginative. When they tie for a gold medal at a tournament and fisticuffs result, the rampant display of machismo offends the World Figure Skating Association, and Chazz and Jimmy are banned from skating for life. That is, until Jimmy’s obsessed fan finds a loophole in the rules—the two men can’t skate in singles tournaments, but can compete together as a pair. Reluctantly, they join forces, and hijinks ensue.

Much of Farrell’s charm lies in his improvisation, and when he’s unrestrained and allowed to let crudely outrageous one-liners fly out of his mouth, he’s unmatched. He’s less successful when reined in and forced to conform to his co-stars. Such is the case in “Blades,” where Farrell has to carry the comedic dead weight that is Jon Heder. Best known for displaying his dance skills as Napoleon Dynamite, Heder has about the same acting range as the lovable nerd he popularized. There isn’t much chemistry between Heder and Ferrell during the movie, and it’s easy to see why Ferrell has been getting top billing in the “Blades” marketing campaign. When the two bicker and fight, Farrell displays his talent for improv and obnoxious comedy, while Heder resorts mostly to saying “No, you’re a loser!” and other lame comebacks.

“Blades” plays it safe in other areas, too. The first half of the film has a decently subversive set-up, with directors Josh Gordon and Will Speck focusing on the overwhelming homoeroticism that inevitably will occur when two men figure skate. It’s not subtle or sensitive by any means—a montage set in an all-male dance studio features the usual stereotypes, and there are more than a few shots of Farrell and Heder executing a skating move, only for one of them to look up and see his hand on his partner’s crotch. Any time someone onscreen says, “Two men can’t skate!” just mentally substitute “get married” for “skate,” and it’s a little funnier.

This angle falls flat pretty quickly, however, and is traded in for a forced romance between MacElroy and Katie (Jenna Fisher, Pam on TV’s “The Office”), the sister from a team of rival skaters. It feels forced, and, even worse, feels as though skittish producers demanded a hetero love story be shoehorned in.

Other similarly taboo topics are given short shrift, despite the potential for hilarity. As Jimmy and Chazz’s rivals Stranz and Fairchild Van Waldenberg, Will Arnett and Amy Poehler are criminally underused. A couple in real life, Arnett and Poehler have great chemistry, and as a brother and sister skating pair, they give the characters a blackly-funny incestuous vibe that should have been mined for all it was worth.

When “Blades” does veer into slightly outlandish territory, it’s pretty good. In one scene, Chazz and Jimmy’s coach (Craig T. Nelson) shows a video of the fabled “Iron Lotus” move, which ends with one of the skaters suffering a gruesome injury. It’s a good shock that pulls the audience out of its safety zone and, as a result, is utterly hilarious.

Apart from Heder’s decided lack of acting skills, the setup is all there for “Blades.” But the execution is terribly flawed—it would be one thing if “Blades” were hampered only by a poor finish or a slow start, but none of its moves come together.