They Don’t Sweat the Big Stuff : BOB THE GAMBLER by Frederick Barthelme, Houghton Mifflin, $23, 213 pages

The world Frederick Barthelme describes in his latest novel, “Bob the Gambler,” is pretty much the everyday world, with one striking exception: The law of gravity seems to be reversed. Heavy things rise rather than fall. Trouble, instead of weighing people down, inflates them with laughing gas and cuts them free.

Take Ray Kaiser, an out-of-work architect in Biloxi, Miss., who has been living on the earnings of his wife, Jewel, and playing blackjack at one of the Gulf Coast’s floating casinos. One night he runs his credit cards to the limit, empties his bank account and risks it all. In a few dizzying minutes, he gets $50,000 ahead, then loses it and more--much more.

Stunned, Ray paces the docks at dawn, waiting for Jewel to come and pick him up. He tries his new identity on for size: “Suddenly I was the guy in the newspaper who loses everything at the casino. . . . It was too ridiculous, too far-fetched to take seriously. People like me didn’t lose $35,000 overnight. . . . I couldn’t imagine what this would mean to our lives.”

At the same time, like the true gambler he has become, Ray is trying to think of a way to raise more money and recoup his losses.

He tells Jewel about the intoxication of playing for high stakes: “There was so much blood pumping, my skull was hot inside, and the cards were like razors. . . . It’s the only way we can play out of our league. Where it’s like, real. The pro tour, whatever. Whole thing. Real as it gets.”

“That’s something we want?” Jewel asks.

“Yes. Always. Everybody. Maybe the only thing we want.”

Now, in every other casino novel you ever read, from Dostoevski’s “The Gambler” on down, Ray’s words would confirm his delusionary state. Jewel and his 14-year-old stepdaughter, RV, would leave him, or he would have to enter a 12-step program, or both. It would be, in short, a cautionary tale.

But Barthelme (“The Brothers,” “Painted Desert”) couldn’t be less interested. He’s writing an offbeat love story, not a melodrama. The conventions of the latter are evoked here only to be flirted with; they are potholes the Kaisers mostly manage to circumvent in their wobbly path through life.

Take RV--and it’s typical of Barthelme that he makes no attempt whatever to explain or justify that nickname. She drinks and smokes pot, but her claim that it’s harmless--that everybody does it--rings curiously true. She and another girl are found in a motel room with boys at 6 a.m., but it turns out they’ve only been watching cartoons.

Ray’s father dies in Houston. Driving there, Ray thinks, “I wanted to do it right, to feel sad, but I couldn’t.” He blames himself, but we recognize that he’s simply in shock. Ray’s mother is obsessed with the idea that a TV star is visiting neighbors across the street--but Barthelme’s attitude, and eventually ours, is: So what?

Even the title of the novel is a throwaway. “Bob the Gambler” is RV’s nickname for Ray, translated from the title of a French movie they happened to rent at a video store.

Barthelme writes in beautifully clean prose about the junk of our culture, the improvised meals, the fragments of TV shows as Ray channel-surfs, the odd jobs his characters have substituted for careers. And he shows these things to be, in truth, trivialities, not harbingers of doom.

Love not only survives the collapse of the Kaisers’ fortunes, it is oddly enhanced, as if middle-class security were a tether that held them down. Is this believable? After so many cautionary tales, can we accept the opposite--a story that says life cuts us a whole lot more slack than we imagine?

Maybe not. Still, it isn’t easy to argue with the conclusion after “Bob the Gambler” gets so many of the details, the voices, the feel of events so right.