Hours after Congress approved HR 4954 on Sept. 30, a bill that suddenly imperiled Internet gambling, hundreds of the world's best poker players partied at a beachfront Radisson resort in Aruba, toasting their good fortune, until they learned otherwise.

The players lined up near the trays of Caribbean pork and pick-and-peel cocktail shrimp. Some took to the dance floor, twisting to '80s hits. A few, aided by beer, jumped into the pool.

Such exuberant moments typified the poker landscape, given its boom within the past half-decade.

Although government prosecutors maintain that Internet gambling is illegal within the United States, they have been mostly helpless to stop it. Wagering sites are easily accessible and operators can evade U.S. laws by opening off-shore sites. But authorities in the United States recently arrested two Internet site operators as they tried to pass through the country, indicating they intended to crack down. And the new legislation cuts to the heart of the operation, money, by stopping the flow of credit card payments to gambling Web sites.

That money and the power of the Internet to drive the boom is in evidence everywhere in the gambling world. At the Aruba tournament, the UltimateBet Aruba Classic, some 80 percent of the 512 participants qualified online. Devon Miller, 21, won the $744,960 championship check. The UltimateBet Web site paid for a blogger, Gene Bromberg, of Shaler, to write about the event for his online audience.

By the night of the party, Mr. Bromberg had heard the news. Senate Majority Leader Bill Frist, R-Tenn., had attached an anti-gambling bill to a larger measure addressing port security. The bill passed through Congress with some politicians never knowing of its existence. And, pending President Bush's signature, which he provided Oct. 13, the Unlawful Internet Gambling Enforcement Act was to be the law of the land..

Though individual gamblers didn't face an immediate threat, online poker players such as Mr. Bromberg recognized what would happen. That night, he mentioned the bill to several others. Their spirits dropped. "Oh, no," one muttered.

"It was kind of strange," Mr. Bromberg said later. "We were having this great party, an amazing time, and yet the world had changed for online poker completely."

Online gamblers, the mass of poker loyalists, in particular, have spent the past weeks assessing the changes, speculating and worrying and searching for last-resort measures to protect their game. Though poker originated centuries ago, the online game revolutionized, and perhaps subsumed, its in-the-flesh partner. Competitors knew Aruba's second-place finisher more by his online handle, JohnnyBax, than by his name, Cliff Josephy.

Rep. Jim Leach, R-Iowa, who helped write the anti-gambling legislation, called the Internet "crack cocaine for gamblers," borrowing the analogy from a professor.

Experts estimate that online gamblers placed $12 billion in bets last year. Some 2,000 poker or gambling sites populate the Web. And many of them, in off-shore tax havens, depend on Americans for half or more of their market.

That's why HR 4954 so quickly crippled the online gambling industry.

"It's ironic that this bill was attached to the port safety measure," said I. Nelson Rose, a professor at Whittier Law School and an authority on gambling law. "Because Bill Frist did more damage to the London stock market than the terrorist attacks. Eight billion dollars in equity, gone, just like that."

"Yeah, but there should have been mayhem, because, for an intelligent, industrialized country to cater to gambling stocks is an anathema to stability," said John Kindt, a University of Illinois professor of business and legal policy. "There should be no sympathy for the people who were involved in this speculative bubble. You cannot gamble your way to riches."

Mr. Bush's signature presented a new level of risk to an industry founded on it. It came on the heels of the recent arrests of Peter Dicks, chairman of Sportingbet, which is traded on the London Stock Exchange, and David Carruthers, chief executive of competing site BetOnSports. News of those arrests sent shares of other Internet casinos downward and worried many in the industry.

Partypoker.net, the country's most used poker site, announced Oct. 13 that it would no longer accept wagers and deposits from U.S. players, though it had depended on them for 90 percent of its revenue. PartyGaming, which operates the site, saw its shares on the London Stock Exchange nosedive. Several other popular sites, PokerStars.com and FullTiltPoker.com, sent e-mail to their customers announcing they'd withstand the turbulence.

Steve Surma, an amateur poker player and PPG employee from Lower Burrell, sent an e-mail in return, thanking the private companies for their fight.

Michael Martin, a Penn State senior who'd participated during the summer in the World Series of Poker, received a message from a poker friend on his Facebook.com message board: "I miss the way it once was."

Mr. Martin's ascension to poker's highest ranks hints at both the game's allure and its inherent danger. He left home in Washington Crossing, Bucks County, more than four years ago, an English major with little clue about his career path and, admittedly, little interest in classes. He began playing poker 2 1/2 years ago. During Christmas break of his sophomore year, he played casually with family members. Back at school, he placed $100 into a start-up online account and idled away time in $5 and $10 games.

He took the game seriously. He studied it. "I saw money," he said. "I noticed that the good players were winning and the bad ones were losing." So he dedicated himself to becoming a good one.

That meant an escalation. That meant a summer job with a moving company that became just an interruption of his poker playing, which consumed 30 to 45 hours every week. It meant a new group of friends, poker players from around the country instead of familiar faces from campus. It meant a house in Las Vegas this summer, a seat in the World Series of Poker and a $42,882 payout at the no-limit Hold-'em championship.

Now back at school for his final semester, Mr. Martin plays every day, often two or three tables at a time. The appeal of the poker lifestyle registers for anybody partial to freedom, independence, competition or long nights in comfortable clothing with a laptop. Mr. Martin, for one, has developed a visceral playing style that fits his personality: He plays by feel and believes he's imbued his online persona, Martine23, with a unique presence and reputation.

One day, Martine23 lost $12,000.

But Mr. Martin never risks more than 5 percent of his bankroll and, since starting his online account, he said, he's netted "six figures."

"A lot of people are saying, 'Oh, these young guys, they don't understand; they're playing because they want a rush and they're dropping out of college as a result,' " Mr. Martin said. "But the thing is, I've been playing online poker for more than two years now. The amount of hands I've played is probably the equivalent of nine or 10 years of live play. So the swings, I've been through them. I know what's coming."

This month, though, the industry has become far more complicated than the game. Predicting the future now necessitates guesswork. Regulations for the Unlawful Internet Gambling Enforcement Act have to be developed during the next 270 days.

During that time, players and companies have to predict the ripple effects. For instance, how will the United States deal with third-party companies such as Neteller, which takes transfers from banks and passes them to gambling companies? And how will the government interpret poker players' assertion that their game is one of skill, not luck, and should, therefore, be exempt from gambling legislation?

And then there's the larger uncertainty: How does one go about squashing a $12 billion industry?

"Prohibitions don't work," said Michael Bolcerek, president of the Poker Players Alliance, who recommends regulation and taxation for poker Web sites.

Mr. Bromberg cashed out last week at several Web sites that closed to U.S. players. Some players decried the legislation, calling it an affront to free will. Mr. Kindt, who testified in Congress about the anti-gambling issue, applauded the government, saying gambling drained personal finances and impeded education.

"Long term, there's no way you can win," he said.

Mr. Martin, of Penn State, graduates in December. After that, he will depend on poker for his well-being.

After he returns from poker trips to the Bahamas and Australia, he'll plan his next step: He'll find an upscale apartment and set one room aside as an office for poker. He'll dress it up with a huge desk, a flat-screen television set and at least two monitors hooked to his computer so he can play up to eight tables at once.

He'll live somewhere beautiful, he said. Maybe Barcelona, Spain, or Amsterdam, the Netherlands, or Reykjavik, Iceland, someplace far away, where he can make or lose his living without interference.