But all these livelihoods hang by a legal thread. "It is illegal for anyone to profit from gambling," said an NYPD spokeswoman. "These houses are illegal, and we are always investigating them."

Knowing the law, the clubs try to dodge prosecution by running as private, members-only clubs. They make money by charging "table fees" — averaging $3 per player every half-hour — rather than "raking the pot " — taking 10 to 15 percent off the top of each pot, a more obvious violation of the law.

"Generally speaking, illegal gambling is the house taking a percentage of the pot," said Barbara Thompson, spokeswoman for Manhattan District Attorney Robert Morgenthau.

Club owners rely on this gray area to stay open. And they say they run clean clubs to keep police attention at a minimum. "We don't serve alcohol, and you have to be over 21 and a member to play," said the manager of the second-largest club. "We think of it as a sober environment where people can compete and socialize. If I see I guy 'on tilt' and he runs down to the ATM, when he comes back up, I stop him from getting in and say, 'You know, tomorrow's another day.' "

Labels: gambling, New York, poker