"Rapture Online," "Heavenly Bodies," "Spend The Night" ... they may sound like movies you wouldn't want your kids to see but they're actually video games you wouldn't want your kids to see.

And that's okay, say some developers, who recognize that gamers are growing up and some may want more mature, perhaps erotic, perhaps violent titles, like the 19 titles that received Adult Only (AO) ratings from the Entertainment Software Rating Board -- including Rockstar Games' "Grand Theft Auto: San Andreas" and Vivendi's "Leisure Suit Larry: Magna Cum Laude Uncut And Uncensored." While a game with an AO rating is described as one that should only be played by someone 18 and older, the reality is that those gamers will find it all but impossible to purchase them at their favorite video game stores; none of the major retailers choose to carry them. For that reason, say some game developers, deciding whether or not to create mature games has become a difficult one.

"The notion that all video games are toys for children -- which is the mass-market perception of games at retail -- is holding the industry back," says Jason Della Rocca, executive director of the International Game Developers Association (IGDA). "None of the big-league developers or publishers can touch that style of game because they can't sell it, at least they can't push it through their normal retail channels. The highest rating most retailers will carry is an "M" rating -- for gamers 17 and under."

In theory, says Della Rocca, the "M" rating is supposed to be the equivalent of the MPAA's "R" rating (under 17 requires accompanying parent or guardian). But the equivalency only holds true for violent games, not ones with sexually mature content.

"If any game were to have the sort of sexuality of an R-rated movie like, say, '9-1/2 Weeks' -- bam! It would get a [tougher] AO rating," Della Rocca says. "But if you walk into a Wal-Mart, their DVD section runs the gamut from 'Sesame Street' to, yes, '9-1/2 Weeks.' Unfortunately, selling that sort of spectrum of games at Wal-Mart isn't an option. And so, from a sales perspective, even though the market may potentially be there, it's very hard to reach."

The workaround is to create two versions of a game and sell the M-rated version in stores and the AO-rated version online only. That's what Vivendi did with the M-rated "Leisure Suit Larry: Magna Cum Laude," whose AO version -- described as "containing more nudity, uncut sex scenes, and raunchier end sequences" -- is available from Vivendi's online store and elsewhere on the Web.

Other developers, like Glennis McClellan, are relying on the Internet entirely. McClellan is the COO of Republik Games, a Hollywood-based developer which intends to release its first title, "Spend The Night" for the PC, early next year, but unveiled its beta registration site earlier this week. McClellan describes "Night" as an online dating game that will match up two players who can then "meet and act out" by going on a "virtual fantasy-based date."

"It will be a fun alternative to going out on a Friday night, especially if you don't have any plans," explains McClellan.

McClellan admits that she would be naive to think that there might not be a backlash against such games from critics of mature games. But she stresses that her company is being entirely upfront about what "Spend The Night" is.

"I think we will be criticized, absolutely," she says. "But we are being 100% clear that we don't want kids on our site. Players will be restricted to 18-and-up, and gameplay will require a credit card payment for, say, several months of play, which will definitely cost less than going out to a movie."

McClellan is confident that she is at the forefront of a new trend in video games.

"We are forging new ground here," she says. "And we're going to go full steam ahead. We think this is something that adults want -- games that involve grownup stuff. And we intend to give it to them."

If, indeed, McClellan is correct that mature titles, including online-only games like hers (which will go unrated by the ESRB) are a growing trend within the video game industry, one can only imagine the hue and cry from critics who are already wringing their hands over violence in games.

In order to deal with these challenges, just three months ago the IGDA created what it calls its Sex SIG (Special Interest Group), whose chair and founder, Brenda Brathwaite, was the lead designer on -- appropriately enough -- Cyberlore Studios' "Playboy: The Mansion" game.

"We're taking a very responsible approach," explains Braithwaite. "The game designers in our SIG are discussing things like the best practices to keep kids away from mature games, how to keep parents informed about the content, and the need not to hide the existence of interactive sexual content in a game. These are important issues now, especially as we see the mature game sector expanding. I know of four multiplayer virtual sex games currently in development. Ironically, women are behind three of them."

One of the most important issues regarding mature games, says Braithwaite, is making parents aware that they exist and that they need to kept away from their kids.

"Parents have this assumption that all video games are safe for their children, which is clearly not true," she explains. "But doesn't mean that adults shouldn't have access to them."

Braithwaite cites figures from a study by the Entertainment Software Association (ESA) that the average game player is 30 years old, that 43% of gamers are between 18 and 49 years of age and that 19% of all Americans over the age of 50 played video games in 2004, up from 9% in 1999.

"But 35% of all gamers are under 18," she adds, "and, according to the ESA, 92% of the time, their parents are with them at the time their games are purchased or rented. If parents made sure that their kids bought only age-appropriate games, that would solve the problem. But another study -- this one commissioned by the games industry in the U.K. -- tells us that parents tend to let their children play adult games even though they know they are 18-rated. That's where it gets really dangerous -- when parents just ignore the ratings outright."

She describes the recent uproar over the "Hot Coffee" incident -- in which it was learned that there was hidden sexual content in the game "Grand Theft Auto: San Andreas" -- as "a wake-up call."

"It made a lot of parents wake up and go 'What? There's adult content in video games?' It made parents more aware of the ratings and of the fact that video games aren't just for kids," she adds.

But there are others within the video game industry who disagree that there is a growing demand for the sort of games Braithwaite group represents. One of those people is Ian Bogost, a game designer and co-founder of Atlanta-based Persuasive Games and an assistant professor at Georgia Institute of Technology, where he teaches about video games. Just because gamers are growing older, says Bogost, doesn't necessarily mean they are begging for sexually explicit or ultra-violent games.

"Nor do I believe that developers of these games are being unfairly constrained from selling their goods," he notes. "It would be akin to adult filmmakers complaining that they don't have a way to show their porn at the local cineplex. I mean, there's a whole different place where you have to go to consume that sort of content, and it's obviously not at Best Buy or Wal-Mart."

Bogost believes that there are adult themes -- like relationships and peoples' internal struggles -- that would make excellent video games, but designers haven't discovered how to create them yet.

"For example, the developer Majesco announced it would be turning the movie 'Taxi Driver' into a game," Bogost recalls. "Now that's a film about one man's internal struggle which could make a terrific game. But Majesco didn't know how to do that, so it's designing a kind of 'Grand Theft Auto' game where you run around like a madman and shoot people. That's the sort of challenge I'd like to see developers tackle instead of how do I get my sex games or ultra-violent games into stores."

The question remains whether there is an audience for games about internal struggles, or have gamers proven that they prefer to blast away at aliens in first-person shooters?

"I don't really think the kind of game I'm describing has ever been given a chance," says Bogost. "Other media -- like films and books -- offer a whole range of genres from which consumers can pick and choose. Unless video games offer the same sort of choices, unless there's something available not only for 14-year-olds but also for housewives and janitors and stockbrokers and urban professionals, well, then you're really doing a disservice to the medium."

Bogost agrees that, regardless what sort of games adult crave, there needs to be an educational process that makes parents "game literate." And he is writing a book, tentatively titled "Video Game Literacy," that he hopes will explain the medium to parents, teachers, and policy makers. It is scheduled to be published next Fall.

Meanwhile, with the impending release of the next-generation consoles, Bogost suspects there will be more adult games on the market that will take advantage of the hardware's increased graphical fidelity.

"My hope is that there will be continued growth of the independent game industry which will develop more experimental games that will probably be sold through online distribution," he says. "How many of them will contain so-called normal content and how many adult content remains to be seen. But one thing is clear: The public perception of games is currently very fragile and it's very important for those who have influence in altering the public's opinion (to) send out the right messages. One of those messages is that games aren't necessarily for kids. A message I think we don't want to send out right now is, hey, stand back ... we're rolling out the sex games. The industry doesn't need that right now."

Paul "The Game Master" Hyman was the editor-in-chief of CMP Media's GamePower. He's covered the games industry for over a dozen years. His columns for The Reporter run exclusively on the Web site.