Melissa Boyle is a 32-year-old mother of two from McKinney, Texas. But when playing a game called The Sims Online, she's Red Dog, a thirsty young man who goes from house to house looking for beer.

"When I first started playing him," says Boyle, "I found it very hard to be a guy. Then, I just fell into character."

Boyle is one of 35,000 people who played the highly anticipated Sims Online game while it was being tested by its manufacturer, Maxis. It was released Tuesday.

More than 20 million copies of its offline predecessors, The Sims, have been sold since 2000. The series began in 1989 with Sim City Classic, which allowed players to develop and build an entire metropolis.

"[The Sims Online is] the only game that lets me make some pizza, flirt with a disgruntled cowgirl and then go dance my butt off, all while being watched by as many as 50 or so real people," says John C. Richardson, of Rochester, N.Y., co-founder of the fan site www.the simsworld.com. "Sims Online isn't just a new game, but a new medium for human interaction and expression."

Here's how to play the game:

A player must first buy The Sims Online CD-ROM, which costs $49.95. (An additional $9.95 monthly fee is charged by owners of The Sims, payable online via credit card.)

After the CD is inserted into a home computer, a menu of options appears on the screen. From this, a player chooses a mythical cyber city in which he or she wants to live. A character is created by selecting the basics - such as skin shade, personality, hair styles and clothing.

Once the character is created, a player logs on to the Internet and enters the virtual city.

It is at this point that the Internet experience differs from the home computer game. The cyber people created by players in other cities, states and even countries now begin to interact with your own - all live.

For example, a construction worker created by a player in Cincinnati might begin dating a nurse developed by someone in Palm Springs. How that relationship interacts with others on line depends on the creativity of the players involved.

"The real attraction for the mainstream [consumer] is the creative element: building your own house, your own business model," says Sam Parker, PC editor at GameSpot.com, a news-and-reviews site. "Its success comes down to having a game that keeps players in the creative process."

While players of the Sims game interact with computer-generated characters, the online version is less predictable, since there are now characters controlled by other players.

"I play the game whenever I can," says Boyle, the creator and editor of an online paper, The Sims Online Neighborhood Gazette (www.tsonews.com) that tracks the development of the game. "I managed to cook a whole Thanksgiving dinner while playing the game. I just had to check back at my computer every 15 minutes or so."

"The Sims has always stood out to me as something that allows you to express yourself on levels that can't be reached in our world," says Richardson. "Bringing that experience online amplifies this expression - in spades."

The compelling part of Sims Online is the social interaction, for players as well as characters.

Many people who played Sims Online during the test phase chose to live in small, Friends-like groups that offer support and share resources.

"I have [made] friends in England, Amsterdam and Australia," says Boyle. "I've met 13-year-old boys to 65-year-old grandmothers. My roommate [in the same online house] lives in Oklahoma."

The Sims Online mimics real life only to a degree. For instance, Sims can die of neglect, if you trap them in a house and don't feed them, but they can't attack another one directly so there's no chance of shooting a cheating lover.

While Parker says he's not sure how many people will want to pay a monthly fee, he's not discounting this premise. "The Sims has already had a strong impact on the gaming world, as far as getting people who don't belong to the basic demographic interested in gaming. And The Sims Online has the potential to do the same thing for online gaming."

"It's the ultimate self-portrait of our society," says Richardson. "I literally think that a few years down the road, we'll all be able to look back on and make assumptions on global human emotions simply based on what we saw and did within the game."