Rani Singh is the daughter of a diplomat, a striking, olive-skinned young woman with flashing eyes. When she made her fashionably late entrance at the Pierce Street Annex, the backgammon tournament was already underway. She perched on a bar stool, her salmon-colored chiffon blouse settling around her, and ordered Grand Marnier on the rocks.

Backgammon -- the serious kind -- is played nightly at the Pierce Street Annex and on this Monday night a tournament was underway. Singh goes to a different place to play backgammon every night, she said. Pierce Street's tournament organizer called her "one of the best lady players I've got."

Singh is not alone in her enthusiam. She is an avid backgammon player, a member of a flourishing local cult united around persuit of the gammon. Singh and her compatriots are stuck on the competition and the thrill of winning. And they can always find a home for the evening among the tables of the Pierce Street Annex, The Saloon, Elan and the Dupont Circle Club.

Washington backgammon establishments are as varied as the personalities who frequent them. The Pierce Street Annex and the Dupont Circle Club, both popular haunts for backgammon enthusiasts, have starkly contrasting atmospheres.

At Pierce Street, a well-known singles bar on the 19th Street strip, dim lighting, throbbing disco music, the clink of ice against glass, the clap-clap of dice being thrown and checkers advancing greet the evening visitor.

At the members-only Dupont Circle Club, a harsh fluorescent glare illuminates the room, which its industrial carpeting and a bulging garbage bag in the corner of a cluttered studio kitchen. Middle-aged and older people sit at wobbly card tables in this basement efficiency apartment, smoking, drinking instant coffee, spinning dice. The murmur of their conversation is the only music of the evening, interrupted by an occasional laugh or triumphant shout.

Participants say Pierce Street is "a friendly place" to play backgammon "for fun." Some say they show up at the weekly affair to see friends they've made at other tournaments or private games around town.

But the buck apparently stops there. Players say the real money to be made in backgammon changes hands elsewhere, at places like the Dupont Circle Club.

Player Richard White of Potomac is the dapper, trendy type, who is still wearing his pin-striped suit. At the backgammon board, his expression is stern. In conversation, he is self-assured. A two-time winner of the Pierce Street tournament, he seems to have an inside track on the local backgammon scene.

"There's a lot of big backgammon action all over town for thousands of dollars," he said. "It's a superb game to gamble with, a quick game. People play backgammon for very high stakes, but the top people in town wouldn't come here."

White's assessment of where to play backgammon profitably was backed up by other players at the Pierce Street Annex. "I go to all of the tournaments, every night of the week," Singh said. "But the most I ever won was $300, in a private bet."

Singh said she has frequented the games at Elan, as well as those at the Dupont Circle Club.

"You can play for money (at the Dupont Circle Club)," said Singh. "The hard core backgammon players go there. Sometimes it's just a lot of little old men. But the good players bet from $5 to $20 for one point."

Backgammon experts say there are two to four points in an average game.

Player Kent Goulding is a serious gamesman. He showed up late at the Pierce Street tournament because, he said, he's been at the Dupont Circle Club, where he's just won $100.

"Backgammon at Dupont Circle is pretty serious," Goulding commented. "It's like the men come to the club on their way somewhere else. There's a lot of gambling there."

Jim Hahn, a salesman, who manages the Dupont Circle Club on Friday and Saturday nights, described the workings of that establishment.

"(The club) is members-only but anyone can join," he said. "You could win 50 cents to $50,000. Well, no, make that $10 to $1,000."

When asked whether such activities were legal, Hahn responded, "It's legal because we don't control the betting at all, we just provide the space. And if anybody wants to come in and learn, they can. We just teach."

"Chouette" is one variation on backgammon at the Dupont Circle club.

In this version, several people play against one person. For Jon Hiratsuka, a government worker, the chouettes played at the club were his main reason for joining.

"In chouettes," Hahn explained, "as many as six or seven take on one person. That one person is in the box. If he loses, he loses all of them. He could lose a lot of money." Of course, the attraction is that the player might also win big.

But backgammon's main attraction, many players say, is that it's just plain fun. Nozar Rahimian, for instance, has loved backgammon since he was a child in Iran, where he says the game has been popular for many years. Others enjoy it as an alternative to chess, bridge or, in Hahn's words, as "a social icebreaker."

"I love the game," said Dave Cloyd, a Texan who now lives in Alexandria.

"It's the immense variety the game offers due to the dice. It offers more variety than chess. It's not the chance that makes the game fun but it adds variety. Something could come out of the blue."

Bill Taylor, a salesman from Lynchburg, came to the Dupond Circle Club while visiting his mother, who is a bridge-playing member of that establishment.

"I'm a social backgammon player," Taylor said. "I don't really enjoy the heavy stakes. I can't look at someone and call them my friend and take lots of money from them, especially if they're married and have children like I do."