SAN FRANCISCO — Shooting. Killing. Vehicular mayhem. Sexual conquests. Teenagers can experience it all in today's almost-anything-goes breed of video games, primarily those rated "M" for mature.

The Entertainment Software Rating Board, which is responsible for the rating system, has suddenly found itself on the hot seat. Critics say the self-regulating video-game industry group's guidance is toothless and does little to help parents who are trying to protect impressionable children from questionable content.

"There is no doubting the fact that the widespread availability of sexually explicit and graphically violent video games makes the challenge of parenting much harder," said U.S. Sen. Hillary Rodham Clinton, who asked the Federal Trade Commission last week to investigate one of the most violent titles, "Grand Theft Auto: San Andreas."

In this "M" rated game, which was last year's top-selling console game, the main character seeks bloody vengeance on gang-filled streets, firing automatic weapons and picking up scantily clad women.

But what really riles family-oriented watchdog groups is what goes on behind the scenes: additional, hidden images in which nude "girlfriends" join in explicit sex acts. These scenes become "playable" with the help of a freely available download created by a Dutch programmer.

"Grand Theft Auto" publisher Rockstar Games Inc. says the game's designers did not create that content. Not so, says the programmer, Patrick Wildenborg. He insists that his modification merely unlocks code in the game's retail version.

Had such sexually explicit content been a part of the retail version, the game probably would have received an "adults-only" rating. And that could have cost Rockstar Games millions in lost sales.

The Entertainment Software Rating Board's president, Patricia Vance, cautions the public not to jump to conclusions while the board investigates.

"I think it is very important for people to realize that this game is rated 'M' for mature," Vance said. "This game is not a game that was rated for children. Regardless of what, if anything, was modified, it's a game that the ESRB has made as clear as it can that it was not intended for anyone under the age of 17."

The board is accustomed to pressure; it was formed 11 years ago under heat from Congress to crack down on violent video games. It now issues ratings for more than 1,000 game titles each year.

How games are rated

As part of the process, game makers must submit a lengthy form describing the most extreme content and turn over visual samples and scripted dialogue as each game nears the final stages of development.

The board then hires ordinary New Yorkers to test the games and recommend ratings, from "E" for everyone to "AO" for adults only. At least three testers try each game, and recommended ratings are delivered within five days, Vance said.

"At the end of the day, what they're looking at is not how fun this game is," Vance said. "We're looking for objective, independent feedback."

That feedback goes to a board of executives from the largest video game companies, including heavyweights such as Microsoft Corp., Nintendo of America Inc. and Electronic Arts Inc., as well as Take 2 Interactive Software Inc., the parent company responsible for the Grand Theft Auto series.

Similar ratings for movies have been determined since 1968 by the Motion Picture Association of America under a system that is also voluntary. Ratings can sometimes be of little use to parents and gamers who are deciding on a purchase. Is Atari Inc.'s "F/A-18: Operation Iraqi Freedom," which allows the player to "Kick some Ba'ath" by dropping bombs on targets inside Iraq, the same as Her Interactive Inc.'s "Nancy Drew: The Secret of Shadow Ranch"? Both are rated 'E.'

Oversight needed?

Dennis McCauley, who runs GamePolitics.com and follows industry issues, says that the Entertainment Software Rating Board generally does a good job of determining ratings. But he thinks it is a problem that the board only answers to itself.

"My primary issue with it is that it's not accountable to anyone. It's kind of a closed loop," McCauley said. "They need to have some kind of mechanism to interface with the public, and not necessarily the government, because some people would see that as censorship."

Rep. Joe Baca, D-Calif., says a good dose of government oversight is exactly what is needed. Baca says parents are being misled. He thinks video game publishers seek the "M" rating even when they know a game includes content that should be in "AO" territory.

"They know very well that if it said 'Adults Only,' these would not be displayed at a Target, at a Wal-Mart or any of the other video game (retailers) because they wouldn't be sold," Baca said in an interview.