Anyone who doubts that much of what we find funny grows out of such negative emotions as cruelty, hostility, and anger, should see "Dinner for Schmucks," which exploits a great many distressing situations and pitiable people to create most of its humor. Loosely based on a sadly unfunny little French movie of some years ago, the American version achieves a much more successful level of comedy, but also exploits its situation with considerably more nastiness than the original.

The film follows an ancient comic tradition in showing the eventual triumph of a well meaning innocent over the far more sophisticated and sinister people who intend to mock and shame him. It also inspires a certain nastiness in the audience, who by responding to the gags and jokes inevitably participate in the cruel game of the title, a kind of temporary and most uncomfortable identification with the bad guys, a gaggle of smug, sycophantic financial wheeler dealers. The picture suggests a world largely populated by villains and phonies, not the usual environment of comic cinema.

Paul Rudd plays Tim Conrad, a rising star in his investment firm who, to earn acceptance from his boss and his fellow executives, must attend the dinner of the title, an occasion for which each person brings some kind of moron or idiot (their words) for them all to make fun of; they award a trophy to the most outrageous fool, the one who amuses them the most. He reluctantly accepts the invitation because his job depends on it, but lacks the requisite guest until he literally collides with Barry (Steve Carell), who stepped in front of his car to pick up a dead mouse. Barry shows him his collection of "mouseterpieces," stuffed mice he dresses in appropriate costumes and poses in imitation of famous paintings - he's proudest of his "Mousa Lisa" and his "Last Supper," with a mouse Jesus and mice disciples, and Tim realizes he's found a winner.

Unfortunately for Tim, through a series of misunderstandings and complications, intensified by sheer stupidity, Barry enters his life, and everything rapidly goes to hell. Barry inadvertently breaks up Tim's relationship with his girlfriend, destroys some of his furniture, wrecks his Porsche, and entangles him with a sexually voracious stalker. On top of all that, Tim offends Barry's boss at the IRS, who retaliates by ordering an audit of his tax returns.

With the exception of Tim and his girlfriend Julie (Stephanie Szostak), just about everyone in the movie exhibits some version of foolishness, insanity, or simple viciousness. Aside from Tim's cruel boss and his loutish colleagues, the sex-mad stalker, Darla (Lucy Punch), and a ragingly narcissistic phony of an artist (Jemaine Clement) suggest a deranged world, a country of the crazy, where a normal person barely survives.

At the climactic dinner party, Tim's boss, his colleagues, and an important client all take a sadistic delight in ridiculing their unsuspecting victims, a group who rival Barry in eccentricity, nuttiness, and, sadly, vulnerability. The guests include a man who feeds a vulture from his mouth, a blind swordsman, a ventriloquist with an antagonistic female dummy, and a medium who communicates with dead animals.

The innocent guests all perform for their tormentors, and a couple of them stand out from the crowd. The medium ruins everybody's appetite with a dramatic reenactment of the suffering and death of her lobster, while Barry pleases the crowd with an epic display of his mouseterpieces, culminating in a sort of tribute to his new friend Tim. The dinner ultimately explodes into complete chaos when Tim informs the guests of their real role in the terrible game.

Full of the kinds of complications and misunderstandings that fuel comedy, the picture never falters in its pace or loses sight of its obligation to generate laughs. The script provides just about all the actors with a chance to perform some exaggerated gag, and most of them, especially Lucy Punch and Zach Galifianakis, make good use of the opportunity. While Steve Carell hogs the screen, mugging outrageously, Paul Rudd must occupy the essentially passive and somewhat unsatisfying role of permanent straight man, reacting to the insanity around him, underlining once again the difficulty and seriousness of comedy.