Brad Pitt, like his pal and fellow movie star, George Clooney, makes commercial hits as well as smaller films that are more about art than profit. The neo-film noir Killing Them Softly is among the latter.

Condemned in last weekend’s instant box office reports as a failure, Killing Them Softly earned $6.8 million in its opening weekend. Its total budget, though, was just $15 million.

Despite its marquee star, Killing Them Softly is not glamorous or pretty. It’s a realistic mob drama about betrayal within the crime community and the retribution that must follow. It’s also a showcase that lets some fine actors do their stuff.

Killing Them Softly features Pitt as a thoroughly professional hit man. Regardless of whatever box office gold the film generates, it’s one of his signature performances.

Pitt plays Jackie Cogan, a killer hired to find and kill the dumb criminals who believed they could rob an official mob card game and get away with it.

Based on George V. Higgins’ novel, Cogan’s Trade, the movie takes place in a world its writer knew well. Higgins’ careers included Boston reporter, federal prosecutor, district attorney and defense attorney. Along the way he wrote 20 books.

In large part, Higgins’ gift for dialogue drives Killing Them Softly. His criminals engage in extended, authentic, colorful conversations. The natural, flowing, sometimes intimate talk the characters deliver brings to mind, for instance, the real estate agents in David Mamet’s play and, later, movie, Glengarry Glen Ross.

Johnny (Vincent Curatola), an ex-con whose dry-cleaning business isn’t doing so well in the suddenly collapsed economy of 2008, is mob-connected enough to know about the local card game where wise guys gather to gamble. There’s plenty of money there.

Thinking he’s got a foolproof plan, Johnny recruits Frankie (Scoot McNairy), a freshly sprung con desperate for cash. Frankie wants to bring his Australian, junkie friend Russell (Ben Mendelsohn) in on the heist.

Johnny is skeptical about Russell, a guy who so obviously is more trouble than he’s worth. But Frankie, another guy who’s surely doomed, sticks up for his friend.

Also in the mix, Ray Liotta, a New Jersey native whose previous roles include mobster Henry Hill in Martin Scorsese’s Goodfellas and Frank Sinatra in HBO’s The Rat Pack, suits the Killing Them Softly milieu perfectly in his role as Markie Trattman, the mob’s card game facilitator.

The story goes against the stereotypical grain via the mob’s legal representation. A blandly corporate attorney known as Driver, he plays middle man between the gangsters and Pitt’s Cogan, an outsider who comes highly recommended.

Shot in the underbelly of New Orleans, the movie goes to sparsely populated places, such as a parking garages and the wasteland beneath an elevated interstate, for Cogan and Driver’s sometimes testy meetings.

Just as Cogan and Driver discuss and negotiate, Cogan also discusses the plan with one of his colleagues, Mickey. James Gandolfini co-stars as Mickey, another imported hit man. Gandolfini and Pitt really get into it, two guys ostensibly in the same business, on the same mission, but actually at cross-purposes. Their dramatic yet solely spoken confrontation is another example of the macho guy-to-guy dialogue that Killing Them Softly does so expertly.

Through all the complications, setbacks and stupidity, Pitt’s Cogan carries on like the pro he is. He’s sharp, in his prime and he takes no prisoners. As brutal and unforgiving as the film is, it’s a pleasure to watch Pitt work.