Emily Post notwithstanding, there's probably no gracious way to projectile vomit in your host's living room. And it says something about the darkly funny antics of Carnage that said puking probably doesn't constitute the most socially awkward moment.

Working with playwright Yasmina Reza to bring her acclaimed play God of Carnage to the big screen, writer-director Roman Polanski stays true to the original by keeping the action -- and, by extension, the audience -- trapped inside a well-appointed New York apartment that grows more claustrophobic and uncomfortable with each passing minute.

The flat belongs to Michael (John C. Reilly) and Penelope Longstreet (Jodie Foster), whose child was struck in the eye by a stick-wielding classmate. The assailant's parents, Alan (Christoph Waltz) and Nancy Cowan (Kate Winslet), have come over to the Longstreets to apologize and co-sign a letter explaining the playground events and how they will be resolved.

Sounds simple enough, yes, but as the afternoon progresses, war breaks out -- couple versus couple, wives versus husband, everyone for themselves. It's a subtle gradation from minor verbal misunderstandings and disagreements to full-on shouting matches, goosed along by Penelope's high-strung snippiness, Alan's constant parade of work-related phone calls, and eventually, the single-malt Scotch that Michael serves up.

The notion of well-bred societal elites tamping down a cauldron of human emotion probably dates back to the ancient Greeks, and Luis Bunuel's The Exterminating Angel no doubt still ranks as the granddaddy of movies about trapping the uptight bourgeoisie in a room with their prejudices and neuroses, but what Carnage lacks in originality it more than makes up for in acrid wit.

All four characters feel eminently recognizable, and while both the writing and the acting makes them somewhat broad and larger-than-life, they never tip over into being cartoonish. The cast members parry, dodge and lunge with Reza's lacerating language, and it's a treat to watch them pounce on each other in such close quarters -- this is one of those instances where staying close to the enclosed action of the stage version is the perfect cinematic choice.

While Reilly might be the only person on screen whom audiences think of specifically as a comic actor, the entire cast plays to their individual strengths and keep the laughs coming. We've seen Winslet be sneering and world-weary, Waltz exude polite menace, and Foster tie her emotions into tightly-bound (but always tidy) bundles, but Polanski takes those attributes and mines them for high comedy.

The term funcomfortable has been applied to the squirmy brand of comedy perfected by Ricky Gervais and Larry David, and the all-too-brief Carnage features enough sphincter-tightening comic moments to last an entire season of Curb Your Enthusiasm -- it's a rousing opera of awkward.