If someone asked you to sketch a portrait of a gamer who spends countless hours each week inhabiting an avatar—say, an elf or a warlock—in a virtual fantasy world, what kind of person would you draw? A teenage boy whose pimply forehead hovers mere centimeters from the computer screen?

Needless to say, such stereotypes are misleading. Since 1999, Nick Yee of the Palo Alto Research Center in California has surveyed more than 35,000 players of massively multiplayer online role-playing games (MMORPGs), such as World of Warcraft. He has found that only 25 percent of MMORPG players are teenagers. What's more, nearly 36 percent of players are married and 22 percent have children.

Michelle Ahlstrom and Neil Lundberg of Brigham Young University and their colleagues decided to study married gamers. Does devoting so much time to online games change how couples feel about married life? The answer is Yes—sometimes for the better, sometimes for the worse. What makes a difference is whether couples game together or alone and—when they game together—how they interact online. The new study appears in the February 15 issue of the Journal of Leisure Research.

Ahlstrom and Lundberg advertised for study volunteers on Facebook and MMORPG forums and settled on 349 married, heterosexual, English-speaking couples from across the United States. In 132 of those couples, only one person played MMORPGs—usually the husband. In the other 217 couples, both partners gamed, but one—again, usually the husband—played more often than the other. The couples played many different games, including World of Warcraft, Final Fantasy XI, Guild Wars, Everquest and City of Heroes.

When one member of a couple spent far more time gaming than the other, the couple typically reported dissatisfaction with their marriage. They generally quarreled a lot as well. No surprise there. However, the number of gaming hours did not matter as much as the answer to one very specific question: Did gaming interfere with "bedtime routines"? Couples who did not go to bed at the same time reported less satisfying marriages. Since earlier research by Yee has documented that 82 percent of gaming occurs between 6 and 11 p.m., it is reasonable to assume that gaming interferes with nighttime activities of all kinds.

"Activities that stand in the way of bonding, routines and intimacy are obviously bad," says Lundberg, "and online gaming is just an additional example."

But what about couples who game together? Whereas nearly 75 percent of couples with a lone gamer reported that gaming hurt their marriage, 76 percent of volunteers in mutual gaming relationships said that MMORPGs improved their marriage. "We thought that gaming might be an issue for some marriages and we confirmed that," says Lundberg, "but there was a flip side. We didn't expect that some couples would game together as a way to spend time together. These folks really came through in the sample and said, 'We enjoy interaction in gaming—it's kind of like an online date. We see this as a really positive thing for our relationship.'"

There is a caveat, however. Although couples enjoyed interacting in virtual worlds, spouses that played on the same team—the same "guild" or "clan"—were less satisfied with their marriages than spouses playing on separate teams. Ahlstrom and Lundberg suspect that the more experienced gamers probably got frustrated with their spouses for not keeping up when the team was on a crucial mission. Fortunately, the researchers have some advice for couples whose gaming talent is lopsided: Remember, they say, that one spouse can help the other "level up"—grow as a character by gaining new talents and abilities, such as more powerful spells—even though they are not part of the same guild or clan.

And, apparently, spending time together online also helps some couples level up their marriage IRL (in real life).