Some stage plays translate to screen with ease, and others do not. "Carnage," based on Yasmina Reza's Tony-winning black comedy "God of Carnage," is stuffy and stilted, its real-time, single-location setup a contrivance it never gets over. The four cast members—Jodie Foster (2011's "The Beaver"), Kate Winslet (2011's "Contagion"), John C. Reilly (2011's "We Need to Talk About Kevin"), and Christoph Waltz (2011's "Water for Elephants")—are phenomenal in practically everything, no question about that, and director Roman Polanski is coming off 2010's "The Ghost Writer," a top-notch thriller that became one of his biggest recent successes. Considering the scope of talent involved, it's too bad "Carnage" diverts but never emotionally coalesces before its blunt, "is-that-all-there-is?" ending.

When their young son is bullied by a classmate and walks away with two lost teeth and nerve damage, Penelope (Jodie Foster) and Michael Longstreet (John C. Reilly) invite the parents of the boy responsible, Nancy (Kate Winslet) and Alan Cowan (Christoph Waltz), over to their apartment to discuss the matter. The discussion is cordial at first despite the apparent differences between them—as a bookstore employee and housewares salesman, the Longstreets are a bit more artsy and liberated than workaholic attorney Alan and investment broker Nancy—but then deeper-seated conflicts and accusations begin flying when they don't see eye to eye about how to go about getting the boys to "patch things up." As their talk moves between parenting methods to the education system and then to their personal problems—all of them are hanging by the very thread they use to make themselves look put together—the Cowans keep getting lured back to the Longstreets' apartment for another round of verbal boxing. By the time a drunken Nancy exasperatedly asks, "What are we still doing in this house?" the viewer is apt to want to know the very same thing.

"Carnage" is like a privately shot master class in top-notch stage work that, alas, just doesn't gel on film. Unbroken and raw in front of a live audience, one can see how this sly, mordant tale of modern-day child rearing and marital discord might have wowed the masses. Edited together on more realistic sets, it becomes insufferable once voices are raised and the true colors of its ugly characters shine through. In reality, these two couples wouldn't be able to remain together talking for more than twenty minutes. At a full eighty, the film's rag-tag topics go around in circles. When dark humor turns to drama, it's an uneasy switch. Because the viewer does not believe the situation as a whole, it is impossible to invest in these nattering marrieds, no matter how well-acted it is (Winslet especially goes for broke as unhappy lush Nancy). "This is getting to be, like, who cares?" says one character toward the end of "Carnage." They couldn't be more right.