When the chips are down, the real game begins in this look at the clandestine world of professional poker players, otherwise known as rounders. Buddies Mike (Matt Damon) and Worm (Edward Norton) met as economic outcasts at a posh prep school and bonded over cards. But Worm, who lives to fleece, is a hustler at heart and not a smart one, while Mike loves the pure skill and thrill of figuring the cards and, more important, the players. Now they're at the crossroads: Chastened by having lost his savings on an ill-advised bet against ruthless Teddy KGB (John Malkovich), Mike is in law school, working a chump job and living with Jo (Gretchen Mol). Worm took the rap for a scam he and Mike ran together; now he's out of jail with a tattoo on his arm (the ace of spades -- an ace up his sleeve, get it?) and a hankering to get back in the game so he can pay off local tough Grama (Michael Rispoli). Mike's suffocating sense of responsibility to Worm runs smack up against his promise ("I can't believe you still know someone called Worm," Jo sighs) to give up the card rooms. Deeply indebted to Martin Scorsese's MEAN STREETS for its central story of a guy being dragged down by loyalty to a loser, this ode to the allure of clipping suckers and psyching out the competition is richly atmospheric but thin in the character department: It feels oddly truncated, despite nicely textured performances by Norton, Damon and John Turturro as Joey Knish, whose colorful name masks a consummate pro who plays for money, not the rush. The ringer in the cast is Malkovich, who layers a preposterous Russian accent onto his nasal voice. The result is so ridiculous it's almost impossible to concentrate when he's talking.