Ambitious executive Tim (Paul Rudd, right) brings Barry (Steve Carell), a dim-witted taxidermist, to his boss's unusual soiree in Dinner for Schmucks. (Merie Weismiller/Paramount Pictures)

“How sweet to be an idiot,” to quote the comic songwriter Neil Innes. Especially if the idiot in question is Barry, the blissfully dopey taxman/taxidermist played to chowderheaded perfection by Steve Carell in Dinner for Schmucks.

Dinner for Schmucks cements Steve Carell's reputation as a master of sweet silliness.

Barry works for the U.S. Internal Revenue Service by day, but his real passion is stuffing dead mice, dressing them in tiny clothes and placing them in lovingly detailed tableaux. His pipsqueak dioramas include bucolic and domestic scenes, as well as a series of “mousterpieces,” the most impressive of which is his all-rodent rendering of Leonardo da Vinci’s The Last Supper. (I wonder if Barry knows about the gopher museum in Torrington, Alta.?)

Ever on the lookout for expired mice to serve as his models, Barry is in the midst of retrieving one from a downtown street when he collides with a Porsche driven by Tim Conrad (Paul Rudd), a fast-rising young executive. The accident turns out to be a godsend.

Tim’s just one step away from a coveted promotion at his company, a rapacious equity firm called Fender Financial. But to get it, he has to participate in a cruel little game dreamed up by the CEO, Lance Fender (a shark-sleek Bruce Greenwood). Fender holds exclusive little dinner parties for his top people, who have to bring along an idiot for a guest. The more outrageous the idiot, the higher the exec will rise in Fender’s estimation. Barry combines Olympic-level nerdiness with the IQ of one of his dead mice, so Tim figures he’s hit the crackpot jackpot.

Things don’t go so smoothly, however, when an over-eager Barry arrives at Tim’s posh apartment a night early. Tim has just had an argument with his girlfriend, Julie (Stephanie Szostak), a French art gallery director who doesn’t approve of Fender’s game. She has walked out on Tim in disgust, so Barry tries to help, in his inimitably bungling way. I won’t spoil the laughs, but the resulting slapstick chaos finds Tim in a back brace and Barry blithely imitating a penguin while being pursued by Darla (Lucy Punch), Tim’s sadomasochistic stalker.

That’s just the opening round in this bout of benign idiocy, directed by Hollywood yukmeister Jay Roach. If you’re a glass-half-empty type, you’ll say Dinner for Schmucks doesn’t measure up to its acerbic source of inspiration, Francis Veber’s 1998 French hit Le dîner de cons (The Dinner Game). But if you’re a half-full kind of person, you’ll grant that this is one of the U.S. director’s finer efforts. On the Roach scale, it falls closer to his best work, the Austin Powers spoofs, than to his clunky Meet the Parents/Fockers comedies.

Mostly, though, it’s a chance for Carell to unleash his wackiest qualities. His Barry is partly a throwback to Brick (as in “thick as a brick”) Tamland, the witless weatherman he played in Will Ferrell’s Anchorman movies. But it’s also partly a homage to vintage Jerry Lewis. Barry even sports Lewis’s signature little-kid haircut and overbite — though thankfully, when it comes to pathos, Carell has a much gentler touch than the sloppy Lewis. And, perhaps inevitably, there’s a smidgen of The Office’s Michael Scott in the performance, too. Like Carell’s beloved TV character, Barry has a penchant for inane babbling.

Barry exchanges profound thoughts with Kieran (Jemaine Clement) in Dinner for Schmucks. (Merie Weismiller/Paramount Pictures)

If Carell channels Lewis, Rudd amiably occupies the Dean Martin role. Rudd is a fine comedian himself (his performance in last year’s I Love You, Man was inspired), but here he’s content to be the good-looking straight man. Besides, there are more than enough clowns in this circus. Roach has loaded the supporting cast with first-rate funny people, from The Hangover’s Zach Galifianakis to Flight of the Conchords’ Jemaine Clement and Kristen Schaal.

Galifianakis is pure laser-eyed lunacy as Barry’s boss and fellow idiot Thermin, a would-be Uri Geller who may not be able to bend spoons with his mind, but can certainly mess with Barry’s pliable noggin. A hirsute Clement, coming off like a New Zealand version of Russell Brand, is equally mad as Kieran, a pretentious artist with an animal fetish and an elephantine ego. Schaal does her raunchy-Betty Boop shtick as Tim’s ambitious assistant, but she’d be funnier if she had better lines. Lucy Punch makes a greater impression as the aggressively lascivious Darla in the movie’s Fatal Attraction parody. There’s a scene where she forces Tim to propose to her, which briefly gives the film a discomforting edge. It’s one thing to deal with harmless morons, quite another to confront the scary delusions of the mentally disturbed.

In that scene and others, you get the sense writers David Guion and Michael Handelman wanted to lay down a little substance under the jokes. It seems we’re meant to wonder why some idiots like Barry are ridiculed, while others like Kieran pack the art galleries. With their joy in mocking others, Fender and his smarmy, self-satisfied minions may be a commentary on the woeful lack of compassion in corporate America. But Roach doesn’t really do satire – except when he’s producing Sacha Baron Cohen’s films – and the movie ends up simply sticking to a time-worn formula.

Roach isn’t that skilled at farce, either. The movie’s comic centrepiece — Fender’s feast of fools — has some wonderfully weird guests and moments, but finally lapses into ham-fisted mayhem. But if the picture doesn’t achieve its potential, Carell continues to delight us. Coming hot on the heels of his vocal role as a cuddly villain in the animated hit Despicable Me, his performance in Dinner for Schmucks cements his reputation as a master of sweet silliness. This guy is no schmuck at all.

Dinner for Schmucks opens July 30.

Martin Morrow writes about the arts for CBC News.