Last month Blizzard’s Worldwide Invitational annual videogame competition, held each year in Seoul, attracted 50,000 fans—its biggest crowd yet—in no small part because Blizzard chose the event to unveil StarCraft II, the long-awaited sequel. Fans cheered and jeered as 16 top players from around the world demonstrated their battle skills in colorful and dynamic space wars, each contest displayed on huge screens. “A real war could not be as exciting and dramatic as this,” said Kim Do Hyun, a 21-year-old spectator.

Blizzard’s fast expansion into a global company—it doesn’t release sales figures, but subscribers number 8.5 million—goes hand in hand with the explosive growth of the game industry in Korea. Nearly a dozen companies run professional teams of gamers who, like athletes, train together for long hours to win big tournaments. Up to 300 competitive games are held annually for prize money, and two dedicated cable-television channels cover StarCraft and other videogames 24 hours a day. “Korea is the only country in the world where an event like this can fill a stadium,” says Blizzard president Mike Morhaime.

Blizzard is trying to broaden its market beyond Korea. In China, it has enlisted Coca-Cola and other firms as marketing partners. In the United States, it’s seeking to broadcast competitive matches on television. The games are growing fast in Asia, particularly in China.

A handful of foreign gamers are trying to give the Koreans a run for their money, but so far without much success. Nick Perentesis, 22, of Canada, competed in the Seoul tournament, but because he works full time as a waiter, he practices only two hours a day. By contrast, Kim Taek Yong, 19, lives with other Korean teammates in a dorm and practices like an Olympic athlete. Recently Kim won $30,000 in prize money. For Perentesis, there’s still the adrenaline rush.