The games are thought to be especially appealing to South Koreans because they live in small apartments with little physical and psychological space of their own, said Castronova, who has studied the demographics of participants. Although people of both sexes and all ages play, most prevalent are lower-middle-class males in their 20s with unsatisfying professional lives.
"After all, wouldn't you rather be a spaceship captain than pouring lattes at Starbucks?" he said. "I think people recognize at least at a subconscious level that there is something subversive about these games."
Lee Seung Seop was a case in point. He grew up in Taegu, South Korea's fourth-largest city. His family was poor and lived in a shop they ran, a relative said. Lee attended a vocational college near home and after graduation moved in with a married older sister and her family. He worked in a drab, walk-up office that looked like a time capsule of the 1960s, with harsh fluorescent lighting and curling linoleum.
"He seemed like a very normal and ordinary guy," said Park Chul Jin, the office manager. "There was nothing odd about him except that he was a game addict. We all knew about it. He couldn't stop himself."
Park fired Lee about six weeks before his death after repeated warnings about being late for work. Around the same time, Lee split up with a girlfriend, a fellow gamer, co-workers say.
The last weeks of Lee's life were spent largely in an Internet cafe. The PC bangs, as they're called here, are homes away from home for many South Koreans. The cafes typically charge just $1 an hour and are open round-the-clock.
The place Lee frequented has dim blue lighting, a faint haze of cigarette smoke and a hushed atmosphere, the only sound being the soft popping of virtual gunfire. During the day, some customers spend their time writing e-mail or checking stock quotes. Later, the cafe is taken over by hard-core gamers. Lee was among them, often staying through the night, eating instant ramen noodles in front of his computer and napping in his chair.
Lee died on a Friday night. He had been at the keyboard since Wednesday.
"He just fell off his chair. His eyes were open, he was conscious, but we could tell right away that it was serious," said Kim Jin U, who was there at the time.
A police investigation attributed the fatality to excessive game playing. But gamers say Lee's behavior wasn't very different from that of countless other young men.
"If you could die from playing too many games, I'd have been dead long ago," Kim said. "I just can't believe it."
With cases like Lee's, the industry has become more aware of the potentially addictive nature of its product.
NCSoft Corp., South Korea's largest game developer, has put warnings in its popular "Lineage" and "Lineage II" games alerting players that after an hour online, they ought to take a break for the sake of their health.
"We want a decent, healthy gaming culture. Of course, you can't force people not to play games, just like you can't force them not to smoke," said an NCSoft spokeswoman, Min Ji Seon.
In the nation's 25,000 Internet cafes, minors are barred entry between 10 p.m. and 9 a.m.
Recently, the South Korean media have delighted in offering up cautionary tales about children skipping school or stealing money from their parents to buy expensive gaming paraphernalia. In the modern-day equivalent of collecting and dressing dolls, girls purchase online characters called avatars, then buy them the latest virtual clothes and accessories -- everything, of course, existing only in cyberspace.
The father of a 7-year-old boy wrote to a newspaper complaining about his son using the parents' cellphone and their computer passwords to buy $300 worth of goods.
But even South Korean children today seem aware of the pitfalls of spending too much time on the Web.
At a cafe in Seoul, two 12-year-old boys listened politely to a government psychologist's pitch and then resumed playing "KartRider," a wildly popular online racing game. But they broke off after 20 minutes, saying they were going home for dinner.
"The games are fun. They relieve stress," said Jeong Dong Hee, who admits to spending up to 14 hours a week playing online. "But I know it's important not to play too much. We need exercise, and we need to study."
"I don't want to become an addict," said his friend, Song Ji Woo. "I want to be a lawyer."