"Even before the invention of scissors, we have evidence of tripartite hand games," said Jason Simmons, who will do color commentary when the tournament is shown on ESPN in July. Simmons, who organized the Burning Man contest in 2001, is known in these circles as Master Roshambollah after roshambo, the French name for the game.

"It's been played under many names for probably millennia. But this is as big as I've ever seen in terms of the spectacle, the preparation of the players, the media interest and the size of the actual site."

Anheuser-Busch is the engine behind the national tournament. Beer distributors organized tournaments at bars around the country, producing regional finalists, and the company put up the prize money and paid for each finalist and a guest to fly to Las Vegas for three days.

Many contestants were having a bit of trouble getting their heads around the idea that they were in Las Vegas, on a free vacation, just to play in a rock, paper, scissors tournament.

"Everyone thought I was lying," said Rachel Fricker, 24, a nursing student from Harrisburg, Illinois, who had not been on a plane before this trip. "Nobody believed that rock, paper, scissors was a real big thing. I didn't either. Then one day, I was at Poor Boy's Lounge, and they asked me to play, and I did, and here I am."

While many said the free trip was reward enough, others had hopes for the top prize. Among those was Antony Maanum, 26, of Overland Park, Kansas, who won his passage at Maloney's Bar and Grill in Shawnee Mission, Kansas. Maanum was dressed in a custom-made red silk boxing robe with white lettering on the back that read "Antoine 'Shears' Maanum," and explained that he was wearing red cooking mitts because "my hands are just too hot."

The costume and the Ali-like persona, he acknowledged, was part of his strategy.

"It's kind of silly, but you see boxers all the time, and they're cocky and they're full of attitude, and I thought I'd take it to another level," said Maanum, a lifelong player who said he became so good as a child that others would only flip coins with him to decide things. "I'm definitely serious when I'm playing the game, but with my costume my opponents don't think so. And I beat them."