By day, Tak Kwok is a mild-mannered project leader at a large international bank. By night, he defends the country and often the planet from alien invasions, crazed terrorists, hordes of the undead and a whole host of nameless baddies.
Kwok, 42, is one of the tens of millions of Americans who are finding an escape in video games. The Entertainment Software Association says 50 percent of Americans play video or computer games, and 40 percent of them are women.
"It takes me out of the environment that I'm in," said Kwok. "It takes my mind off of work and relieves stress."
He doesn't have much time to play around during his 10-hour workday. But when he gets home, it's a different story.
"I get home, have something to eat, flip on the television for a bit and then I turn on my PC," he said. "I play for about an hour and a half or two hours, wash up and then it's bedtime."
Justin, a vice president at a high-powered Wall Street financial services firm, is a closet gamer. He didn't want his last name used, because he doesn't want anyone to know.
"If I'm hanging out with some friends I might talk about a great game of Madden [football game] I played the other night," he said. "But it's not the kind of thing you bring up at a business lunch or something."
The average gamer is 29 years old, according the ESA. But people of all ages, and from all walks of life, are taking up gaming.
"Pretty much everyone is playing," said Chuck Osborn, senior editor of "PC Gamer" magazine. "We have readers that run the gamut from their teen years all the way into their 60s and 70s."
And some of those older gamers are just as rabid as the younger ones.
"We received a letter from a woman who was very upset, wanting to know when "Half-Life 2" [a highly anticipated action game] was coming out because she was disappointed she wasn't able to receive it for Mother's Day," said Osborn.
But if so many Americans are doing it, why are so many gamers hiding?
"The time commitment games as a hobby usually require is quite odd and makes admitting to liking games sort of strange," said Greg Kasavin, executive editor of Gamespot, a gaming Web site. "By doing so, you're admitting you have a lot of free time and you're not mountain biking and going to the movies and stuff."
Kasavin believes that because of the perception many people still have about gamers as geeks, nerds and social misfits, video and computer games have become one of those things that people do, but rarely talk about.
"Historically that's been one of the biggest parts of the stigma," said Kasavin. "If you're into games you must be some weird loner who sits in his mother's basement or something."
According to the ESA, this stigma didn't stop Americans from buying around $7 billion worth of video games in 2003 -- more money than the Hollywood film industry made last year.
ESA President Doug Lowenstein thinks he knows why.
"For people who've grown up with interactivity, it's an integral part of their lives," he said. "For them it's as natural as radio was for my parents, or TV was for me."
Lowenstein also believes that games satisfy a part of us that goes relatively unfulfilled in films and television.
"In a game you're in control, you're the author," he said. "It is a fundamental part of human nature to want that, and video and computer games are the only forms of entertainment that allow you to do that."