Hollywood studios have released 33 percent more R-rated films in 2012 than last year, but the wealth of adult offerings hasn't translated into a box office boom. Instead, audiences have flocked to PG-13 fare.

This year, 168 films have carried the "restricted" rating, which requires youths under 17 to be accompanied by an adult, and they have taken in $2.3 billion at the box office. That compares to 113 PG-13 films, with a $4.7 billion take, and 52 PG movies with a combined gross of $1.8 billion.

Only one R-rated film, Universal's "Ted," has cracked the year's Top 10 grossing films. Six of the Top 10 -- including the top four -- carry PG-13 ratings, while three are rated PG. In 2011, nine of the Top 10 movies were rated PG-13 with the remaining slot taken by "Cars 2," with the all-but-extinct G rating from the Motion Picture Association of America.

So if the money is in PG-13 movies, why do the studios keep releasing more R-rated films?

[5]"In most cases, you don't really make a decision -- or have a choice," Lionsgate's head of distribution, Richie Fay, told TheWrap. "It's usually a case of what the material demands, and whether it's organic. But you know all that going in -- it is part of the process. You see it when you read the script, and you factor it in when you're planning."

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Indeed, the majority of the R-rated releases aren't major studio productions, they are independently produced and niche films. For example, nine of the 12 films released this year by  the Weinstein Company, which focuses on adult specialty releases, were rated R. But of the 19 films released this year by market-share leader Sony, only four were rated R, two were PG and the remainder were PG-13. Eight of Universal's 14 releases this year have carried an R, but none of the 11 movies released this year by Disney have been R.

There is money to be made. Besides the top-earning R-rated film "Ted," Universal scored with the R-rated "Safe House" ($126 million), "Prometheus" did the same for Fox and Sony had "21 Jump Street" ($138 million). Even with PG-13 appearing to offer the most direct shot at blockbuster box-office numbers, there are reasons the studios make R-rated films, Universal's distribution chief Nikki Rocco told TheWrap.

[7]"Mainly, you want to stay true to the material," Rocco said. "You couldn't make a film like 'Savages' anything other than an R. By the time we greenlight a picture, we know what its rating will be."

Creative considerations aren't all, though.

"Another reason is to bring some diversity to the marketplace, to offer something for specifically for adults, so that there is in theory something for everyone out there," Rocco said.

Warner Bros. had six R films among its 14 releases (not counting Imax nature films and re-releases) and had a major hit with the R-rated "Magic Mike," which cost just $7 million to make and took in $113 million domestically. The studio's Oscar frontrunner "Argo," which over the weekend topped the $100 million plateau at the box office, is also rated R. That rating won't hurt should the film claim a Best Picture nomination; seven of the last winners at the Academy Awards have been R-rated.

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Obviously, an R-rating offers filmmakers the ability to more accurately portray real-life situations. But that’s not the goal for every filmmaker. 

“If Spider-Man were really out there battling crime in the streets of New York City, don’t you think he’d be inclined to drop an F-bomb now and then?” wondered Exhibitor Relations senior analyst Jeff Bock.

He might in the real world, but he won’t be dropping them at the multiplex anytime soon. Nor will Batman or Katniss Everdeen -- at least not if they intend to draw the droves of teenagers that power the grosses of the biggest franchise films.

There was never any doubt that the “Twilight” films – including the nation’s current top film for two weeks running, “Breaking Dawn 2” -- were going to be rated PG-13, according to Fay.

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Author “Stephenie Meyer was very specific with her edict that there would be nothing in there that would put us in the position of getting an ‘R’,” Fay told TheWrap. “She knew the audience that bought the books and had a lot of communication with those folks, and she was very clear on that.”

Both Universal and Warner Bros. have successfully bucked the trend with comedies recently, Warner Bros. with its two “Hangover” films and Universal with this summer’s “Ted.”

“They’ve shown you can get away with an ‘R’ with comedies,” Bock said. “But with an action film, if you want to make $200 million, $250 million at the box office, you’ve got to get the biggest possible audience in there.”

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This year’s top four films  -- “The Avengers,” “Dark Knight Rises,” “The Hunger Games” and “The Amazing Spider-Man” -- are all rated PG-13.  And of the top 25 film franchises of all time, only one  -- “The Matrix” -- carried an “R” rating, so it’s a dollars and cents issue. It’s hard to imagine any project with franchise potential -- and a franchise-sized budget -- could get a studio green light today without assurances that it could play to teenagers. 

This summer’s “Prometheus," tied to director Ridley Scott’s earlier “Alien” film, was the rare R-rated project that seemed to have franchise potential. It opened to $51 million in June and topped out at $126 million domestically. The grittiness and freedom that the R rating allowed Scott no doubt lured some adults, but it's impossible to determine how much it would have made had it been more accessible to teens.

Dick Rolfe, who heads the Dove Foundation [11], a nonprofit organization that has been trying to push Hollywood in a more family-friendly direction for more than two decades, isn't surprised that audiences are choosing the non-R titles.

“I think there is a kind of wearing-out of the public in terms of explicit material,” Rolfe told TheWrap. “People are just getting tired of exploding body parts, naked body parts and abusive language.”

On the other end of the ratings spectrum, the “G” rating has essentially vanished. There were only nine films released with that rating this year. Three were re-releases, two were Disney nature films and the other four were independent animated kids films. Among those was “Oogieloves: The Big Balloon Adventure,” which set a record for box-office futility.

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“It’s just not cool for kids -- at least kids old enough to care about stuff like this -- to go to G-rated films anymore,” Bock said.

There were 261 films that were released without MPAA ratings, mainly small foreign films, independent features, documentaries and re-releases. They grossed $45.4 million, or an average of $174,000.

Only two films have been released with an NC-17 rating in 2012. LD Entertainment’s “Killer Joe,” which starred Matthew McConaughey, grossed $1.9 million and Kino Lorber’s “Elles” brought in $754,000.