Gamers will never get to play Manhunt 2.

Yes, sometime this year you might be putting a disc labeled Manhunt 2 into your Wii or PlayStation 2, and stepping into the shoes of Daniel Lamb, a mental patient who has to escape an insane asylum by killing the guards in the most gruesome manner possible. But it won't be the game the creators originally intended.

The developer, Rockstar Games, had the code polished and ready for a July ship date, but was forced to slam on the brakes when the Entertainment Software Ratings Board, or ESRB, gave Manhunt 2 a rating of Adults Only, or AO, the game industry's equivalent of an NC-17 movie rating.

Neither Sony nor Nintendo allow AO-rated titles to be released on their hardware, and most major retailers refuse to stock the games. As a result, creators whose games get an adult rating usually trim back the content or decline to release the product.

Manhunt's ratings woes, which Rockstar announced to the public, is the first visible sign of a shift in the way video games are rated that's unfolding largely behind the scenes. In the wake of increased attacks on the industry by politicians, the industry-run ESRB and overseas groups have been awarding de facto NC-17 ratings to content that would warrant an R or a PG-13 if it were found in a movie instead of a game.

The ESRB reports about a dozen cases in the past five years in which it issued the AO for violence; nobody has heard of them, because each game was held back and quietly watered down to win a lower rating. In countries like Britain, the problem is even clearer. There, the board that rates video games and films is under the auspices of Parliament, and Manhunt 2 has been de jure banned: Selling it to anyone is illegal.

Game designers are feeling the chill. Developers at Sega, working on the upcoming Condemned: Bloodshot, say the Manhunt controversy caused them to remove some content from their game. And Al Lowe, creator of the Leisure Suit Larry franchise, says that one of his naughtier classic games was left out of a recent collector's edition package because of concerns that the ESRB would give it an AO rating. It was rated M in 1996.

At a conference in Germany this week, Factor 5 developer Julian Eggebrecht – the director of Lair for PlayStation 3 – gave voice to a concern simmering in the creative trenches of the industry. The review process is a "charade," he said, according to Eurogamer. "If you cannot have satire about these things, (it) is approaching the realm of McCarthyism."

While acknowledging an uptick in AO ratings, the ESRB insists its standards haven't changed, and argues that game developers are inviting the rebukes. "As the capabilities of the systems become more complex and the types of content in games becomes much more varied, you're going to find the creators of these games pushing the envelope in a variety of different ways," says Patricia Vance, the ESRB's president.

Vance also emphasizes that the ESRB never requires gamemakers to change their products. Whether a game makes it onto shelves is "out of our control," says Vance. "These are business decisions that are being made by retailers and console manufacturers.... We assign ratings and then the market determines what's acceptable."

Of course, the market can't vote on games that are not allowed to be released. Sony spokesman David Karraker says the company simply doesn't want the PlayStation brand associated with adults-only content, and is comfortable banning anything with an AO rating from its platform without further review. "We want to offer age-appropriate entertainment for our consumers but do not want to be associated with material that is gratuitously violent or pornographic."

Even if Sony did decide to allow Rockstar to put the uncut version of Manhunt 2 on PlayStation, there'd be practically nowhere to sell it. Wal-Mart, to name one giant example, does not sell AO-rated games – though it sells the "unrated" version of the movie Saw III.

It's because the medium of the video game is so new that it gets evaluated more harshly, says Gerard Jones, author of the book Killing Monsters: Why Children Need Fantasy, Super Heroes, and Make-Believe Violence. "Most new media tend to have a fair amount of violence and sensationalism in them. But the very shock value that makes this stuff catch your attention also shocks other people, who see a social or psychological danger in it."

Where this often leads, he says, is to proposals of legislation that are mostly symbolic. "This is an old tradition in politics, this belief that the culture has gone out of control, and that the profiteers need to be reined in," says Jones. "The legislature will then try to nail down some cultural standards through law."

It was talk of such regulation that prompted the formation of the ESRB in 1994, in the days when even the most violent video games were still rendered with cartoonish and crude graphics. It was assumed that the difference between the Mature and Adults Only rating was that the latter was for interactive porn. "At the time, the focus was to protect the rather young industry from becoming a depository for pornography," says Sony's Karraker.

The video game sex controversy exploded again after Rockstar's 2004 release of the blockbuster hit Grand Theft Auto: San Andreas. Hackers found a scene that the designers had removed from the final game, but not deleted from the source code, and published instructions on how gamers could reactivate it.

In the scene, a female character invites the game's hero into her house for some "hot coffee." What ensues is a poorly pantomimed cartoon sex scene in which the two characters bump polygonal uglies with all of their clothes still on. Even though it was far less graphic than any given scene from American Pie, the ESRB changed the game's rating to AO, which caused it to be recalled from shelves.

Sens. Hillary Clinton and Joe Lieberman responded by introducing a bill in 2005 that would make it a federal crime to sell even Mature-rated games to minors. States got into the act as well, and according to GamePolitics.com, 20 different states have recently attempted some form of video game legislation – many of which have already been ruled unconstitutional.

Financial analyst Michael Pachter of Wedbush Morgan Securities estimates that Rockstar will have to sink another $1 million in development time to clean up Manhunt 2. But he blames the company, which he says should have known better than to tempt the ESRB in the first place. "The company should have recognized that it was under a microscope" after San Andreas, he says, "and should have edited the content accordingly."

Representatives from Take-Two Interactive Software, Rockstar's parent company, declined to speak with Wired News for this story. But it was the company itself that went public with the AO rating, before announcing that it would retool the game to win an M rating. Pachter said he thinks Rockstar should have stayed quiet.

"I recognize that Rockstar set out to create a horror genre classic, and the publicity could in some way help by driving awareness," says Pachter. "However, the game we end up seeing will have the stigma of being the edited version, and someone buying it will not be able to see the original uncut version."