The film takes place in the early ’80s, near the dawn of the Reagan era of unbridled financial speculation and massive borrowing. For Dan Mahowny (Philip Seymour Hoffman), it’s an era of promise. At the beginning of the movie, the Toronto bank where he works makes him the youngest assistant branch manager in its history, giving him authority over millions of dollars in credit. Mahowny uses his new power to fund his secret life as a compulsive gambler, betting on pro sports with his local bookie (Maury Chaykin) and dashing off on weekend trips to Atlantic City, where he becomes known as a high roller with a phenomenal tolerance for loss.

Owning Mahowny offers predictable suspense as to when and how Mahowny’s chickens will come home to roost. But the fascination of the story lies in its gliding oscillation between two neatly complementary worlds: the bank, a machine for creating money out of money, and the casino, an apparatus for expending capital and revealing its imaginary nature. With an admirable avoidance of glamor, Richard Kwietniowski portrays both worlds as hiding places for the paragon of conformity who is the film’s bland, isolated hero. Everything is designed, colored in, and smoothed over so that Mahowny can disappear into either world and simply exist, slotted into whatever space and whatever function he occupies at the moment.

His performance of every function is so unspectacular, he could be in a Bresson film. At work, he’s competent and resigned, as if he didn’t expect anything good to happen to him. At home, he acts out, with good intentions but less than total enthusiasm, the role of domestic partner to his devoted girlfriend (Minnie Driver). Playing cards, he’s closed, hunched over, turned inward, his face seized up in a frown of tension, looking as if he could drop dead of a heart attack at any moment. We share in none of his calculations or emotions; instead we see him through the cold eyes of the jubilant casino manager (John Hurt) who follows his missteps on monitors fed by video cameras above the gaming tables. Winning brings him no relief: only by quitting and getting up from the table can he find release from his circle of pain, but this leads only to despair (in his losses) or a sedated exhaustion (when he wins).

Owning Mahowny is honest and direct about the absence of satisfactions in his life: none in winning, none in getting away with stealing and deception, none in being treated like a king at Atlantic City. (Kwietniowski proves himself the anti-Scorsese with an ironic tracking shot, late in the film, of Mahowny’s triumphal casino entrance amid an entourage of guards and cashiers: the pomp and flattery are lost on the shlubby gambler, who’s just there to get on with it.) Gambling brings only endless repetition (each hand is different and the same), postponing the settling of accounts.

He can’t explain his secret life to others, and neither does he feel any pressure to do so, because the others are all facilitators. His girlfriend understands that she can do nothing to bring him back from his obsession, only wait and hold out the promise of a place for him to come back to. He easily meets his bookie’s demands for money. His superiors, his colleagues, and even a bank auditor pose at worst the occasional inconvenient question, which he has no trouble parrying.

A key moment in the film is a private calculation of odds: Mahowny hesitates before going through a doorway to a meeting where his embezzlement may come to light. For him, all life has become nothing but uncertainty and risk; the only sure way to escape disaster is to turn and walk away, abandoning the role, but that would be a step into the void. To go on with the role, to play out the hand, to go into the room — that at least is logical.

Hoffman’s sluglike, almost invisible acting depends almost entirely on such moments. His performance is marvelous, like the spare crappiness of the decor (two-tone blue stripes on a hotel-room wall, the pale greens and deep browns of the bank, Mahowny’s perpetually under-decorated apartment), and like the low-intensity coolness that Kwietniowski sustains through the film.