Carnage is a dull movie to recommend to anyone. Like a lot of movies I’ve seen this season, I liked it enough to give it a vaguely positive review and say a couple nice things about it, but not enough to really remember much a couple weeks after seeing it.

In that respect, it really reminded me of John Patrick Shanley’s equally whelming Doubt, which starred Meryl Streep as a nun who likes to shout and featured Amy Adams crying a lot. This time, Jodie Foster does most of the crying and John C. Reilly the shouting, and their movie doesn’t serve them a whole lot better than Shanley’s.

The two of them play one half of a group a pair of rich, WASP-y couples who spend the film getting mad at each other in a room, kind of like No Exit but with better clothes. In both versions, the two couples come together when one of their sons bullies the other on the playground, and by discussing the violent natures of their own boys, their meeting unleashes the dark sides of all of them. Based on the Pulitzer-winning play God of Carnage by Yasmina Reza, these proceedings have fire and wit on the stage; they crackle, they sting.

Although Roman Polanski and his actors do a fine job of keeping the humor in tact, the movie version lacks the moral provocations of the play, mostly because the actors don’t seem to fully convince us of their innate, God-given savagery. In particular, the usually impeccable Jodie Foster is out of her element. She’s the only actor present without a theatre background and always plays heroines, and so her “dark side” involves tossing her arms around while drunk. As the film goes on, her clueless histrionic flailing becomes tiring. Likewise, John C. Reilly isn’t very convincing as a horrible person, because bad isn’t within his range. He’s played so many good-natured dopes that nothing about him reads particularly sinister.

Thus, the film doesn’t feel like a metaphor for how chaos and carnage rule the world; it’s just a bunch of white people behaving badly.

However, if you are going for that reason alone, you’ll have a fine time. The film may fail as philosophy, but taken purely for its surface value, it’s an intermittent hoot. Polanski keeps the dialogue zipping by at lightning pace, and the cast really sinks their teeth into the script’s pervasive bitchiness, especially Winslet and Waltz, as the more overtly horrible of the two couples. (If anybody knows how to play total jerks in a film, it’s two people who won Oscars for portraying Nazis.)

In particular, Kate Winslet looks to be having a ball, as Polanski and Reza let her play raunchier and nastier than the movies usually let her do. And she laps it up. Most memorably, there’s a scene where Winslet is called upon to vomit all over the room, and I swear that she cracked a smile doing it. Later this year, Winslet is set to appear in Jason Reitman’s Labor Day, which promises to have the same tragicomic tone as all his movies do, and I hope that she commits to exploring the more comedic side of her work. It seems to be liberating for her.

Although it was a joy to see her and Waltz on screen, making a more convincing couple than I thought they might, I couldn’t shake the lack of necessity of a film version after it was over. Carnage adds little to its source material, and Polanski does a poor job of arguing for the need for his own film’s existence, as he lacks a real visual style to match Reza’s script. The end result just looks like a filmed version of the play. So then, how do you go about praising a movie that was only a partially satisfying facsimile of something you can see elsewhere?

Recently, I asked a friend who claimed to have loved it to help me out, to give me one truly compelling reason you should see this in theatres and not wait until video or seek out the play. His response: “The blocking. It’s got great blocking.” So, reader, you should go see this movie because all of the actors stand exactly where they are supposed to until the movie ends. But after that, just go catch the original.