Take one hell of a good director and hand him a successful play. Then give him four absolutely superb actors and sit back, smiling smugly and waiting for plaudits and money to rain down on what should obviously be an extraordinary film.

Except “Carnage” isn’t extraordinary. It’s good, certainly. But it feels a bit like a Yankees team with a $200 million payroll that finishes in third place in the AL East. And that’s a little puzzling.

The film is based on Yasmina Reza’s play “God of Carnage,” set in Brooklyn (a place director Roman Polanski hasn’t visited in more than 30 years) and depicts one afternoon meeting between two couples. There’s been an altercation between two 11-year-old boys. Zachary Cowan swung a small tree branch that knocked two teeth out of Ethan Longstreet’s mouth.

The parents of the injured (or “maimed,” as his mother insists) boy are Michael and Penelope Longstreet (John C. Reilly and Jodie Foster), and the meeting takes place in their exceptionally nice Brooklyn apartment. Michael sells plumbing fixtures and is supposed to be a sort of blue collar-type. Penelope is a bit of a dilettante, dabbling in writing (though Michael insists on calling her a writer) and championing the cause of the people in Darfur.

Into their apartment come Alan and Nancy Cowan. Alan (Christoph Waltz) is a high-powered attorney for a pharmaceutical company whose showpiece drug is starting to cause some nasty side effects. He’s constantly yammering away on his BlackBerry, helping with damage control for his clients. His spouse (Kate Winslet) is an immaculately put together investment banker who feels guilty enough that she ropes a reluctant Alan into staying when he’s trying to leave.

Both couples smugly congratulate themselves on the civility of their discussion, with much talk of how boys will be boys. Alan doesn’t buy into it completely, saying Zachary is “a maniac” and that talking to him will do no good.

It’s here that the cracks start to appear in the friendly veneer, as unsolicited parenting tips are exchanged and accepted first with forced smiles and then with indignant refusals. The Cowans attempt to leave multiple times but are dragged back into the apartment with cobbler, coffee and promises of productive discussion.

Polanski hasn’t been in America since 1978 because he fled the country more than 30 years ago rather than face a 48-day sentence after pleading guilty to unlawful sex with a minor. One can’t help but feel that he took on this material as a chance to shine a light on ugly Americanism and to skewer our fat, dumb, self-righteous country. And that’s why it’s surprising that he leaves the jugular untouched.

I haven’t seen the play, so I can’t vouch for the casting. I do know that James Gandolfini had the role of Michael in the U.S. stage production. He feels a bit more right for the part of the blue-collar plumbing salesman. Reilly’s good, but doesn’t feel really Brooklyn.

Foster’s just fine for the first two-thirds of the movie but starts playing it very big as her character’s liberal guilt and outrage bubble up to the surface. Polanski gives her a lot of close-ups, which make her seem loony, and are a poor choice for Foster, who’s a pro at easy, natural acting. Here she’s contorting to play her part, and it shows.

Winslet and Waltz are a bit better cast, though Winslet gets a bit lame as everyone starts to get drunk on Michael’s prize Scotch. Her acting drunk is way too broad and while it may have made Roman Polanski titter and snort while he was directing her, someone should have said “We really should reshoot this.”

Waltz has the easiest time as his character is a smug asshole throughout the movie, and getting tipsy only makes him a bit more honest. Alan is clearly participating in the meeting under duress from his wife, and it’s not long before he begins to take umbrage at Penelope’s veiled comments and recommendations. He’s aware that his son is a thug and knows that talking with him won’t change a thing, but keeps trooping back into the apartment at his wife’s urging to try to do the right thing, even if he grows increasingly unsure as to what that might be.

The last 20 minutes of the movie, with everyone drunk and screaming at one another, aren’t much fun to watch. As expected, we learn that neither marriage is perfect and that tongues loosened by liquor are as likely to cut loved ones as much as enemies.

But we already knew that. So now what? Polanski doesn’t have a good answer, and the movie really doesn’t have an ending. It just sort of sputters and jerks to a halt and the credits roll. As they do, the audience has time to ponder. What was said? What points were made? What blows were struck?

The answer: disappointingly few.