By Clark Boyd
Technology correspondent in Las Vegas
Think gaming in Las Vegas and you are usually talking poker and blackjack.
Concentration is key to gaming success
But not at the Cyber X Games, where the sound of the slot machines was drowned out, temporarily, by the roar of virtual gunfire.
This past weekend, more than 1,000 gamers from across the globe descended on Sin City, hoping to grab a slice of the $600,000 on offer in cash and prizes.
Teams played against each other in groups of four to six people known as clans.
The competition line-up included some of the most popular multi-player games in the world, such as Counter-Strike, Warcraft III and Return to Castle Wolfenstein.
But for the players, it is the strategy, not the gore that draws them in.
"The motor skills, the hand-eye coordination, the strategy involved, the playing involved is similar to other sports," said Joseph Hill, head of Cyber X Gaming, the company in charge of the Vegas competition.
He sees video gaming quickly turning into something better called electronic or e-sports.
"I really look upon the games themselves as more along the same lines as chess.
"The object, the strategy is to take out certain opponents. It's the oldest game in the world.
"And really, although the technology is played out, it's really not that different in terms of overall approach," he said.
The most popular multi-player game in the world right now, Counter-Strike, is not exactly like chess.
In the game, two teams take sides, as terrorists or as counter-terrorists.
The teams then battle over a series of different virtual maps, trying to take each other out.
Gaming is becoming a sport and a spectacle
The matches are so exciting, that there is even play-by-play coverage, live and online, with shoutcasters, as they are called, providing a running commentary.
Daniel, a 17-year-old from Sweden, plays for one of the top Counter-Strike teams in the world. For him, fate took him from real sports, to virtual ones.
"I played soccer for seven or eight years, and I hurt my knee," he said.
"And I got into gaming because I had nothing else to do," he said. "I got into it more and more, and I now play on a professional level."
Paid to play
Players like him are part of a gaming explosion across Europe, an explosion that has propelled European teams to the top ranks of professional e-sports.
The teams have corporate sponsors who provide computer equipment, and travel money to competitions all over the world.
"I know Russia and China have now accepted it as a sport," said Richard Bennington, an 18 year old from the UK who manages a team made up of players from across Europe.
And some sponsors treat it as a sport, paying salaries to certain teams.
"Everyone is actually having a full-time salary," said Andreas Thoronsson, who manages a sponsored Counter-Strike team.
"With prize money, I think they make about $3,000-4,000 a month, after taxes. It's double the average salary in Sweden I think," said the 24-year-old.
The Swedes are widely regarded as e-sports leaders in Europe.
They have one of the highest concentrations of computers and high-speed internet connections on the continent.
This is crucial when you are playing online games with up to 64 other players.
Tournament gaming is a team sport
Germany is strong too, as are Italy, France and the United Kingdom.
European gamers acknowledge that even their level of devotion is nothing compared with heavily wired South Korea.
Top players there can make $100,000 a year. Some gamers even have Elvis-like followings.
But gamers like Tahir Zafar say they are not so interested in money and fame.
Mr Zafar is a member of a sponsored British team, Four-Kings Intel. They spent up to 10 hours a day preparing for the Las Vegas tournament.
"Start of a brand new year, and you're getting paid to come to Vegas, and we're just having a wicked time," said Mr Zafar.
"It's excellent. That's what I said to everyone when we got here. It's great."
It is good that Mr Zafar and the rest of the Four-Kings team had a relaxed attitude. Lady luck proved as fickle as ever in Vegas.
The Cyber X Games were over almost as soon as they began, as technical glitches forced the cancellation of most of the professional events.
Clark Boyd is technology correspondent for The World, a BBC World Service and WGBH-Boston co-production