Back to high school for Jonah Hill and Channing Tatum

"21 Jump Street" launched Johnny Depp to stardom, although in the Fox show (in which he appeared in 80 episodes from 1987 - 1990), he was not the quirky actor we know today. Depp was positioned as a teen idol in the show about young cops going undercover in high schools. Now, some 25 years later, the series has been re-invented as a Hollywood comedy with two of the industry's hottest actors: Jonah Hill and Channing Tatum.

It's been a busy 2012 thus far for Hill. He was nominated for an Oscar for Best Supporting Actor for "Moneyball," and last week hosted "Saturday Night Live." And he did more than just co-star in "21 Jump Street," which comes to theaters this Friday: he is one of the film's producers and co-wrote the film's story with screenwriter Michael Bacall.

’Bad Boys’ meets John Hughes?

In the film the pair play cops that are put into a special police program where their immaturity could be played as a plus: they're sent undercover to a high school where they are assigned to expose a drug dealer selling a dangerous new hallucinogen. Once back in high school, they soon realize how out-of-step they are with today's generation and try to connect with the cool kids (played by Dave Franco [James' brother] and Brie Larson), who may or may not be dealing drugs.

While the series is based on a popular 1980s television series, it is a number of 1980s films and icons to which Hill wanted to pay homage. "I wanted to make 'Bad Boys' meets a John Hughes movie," Hill said. "I wanted to have a 'Back to the Future' element of reliving the most important part of your youth thinking you have the almanac but all the answers are wrong once you get there. That's what I cared about. That's what seemed like a fascinating story."

’We sound old’

Physically the pair may be able to pass as high school students, but they quickly learn how the culture has changed and how removed they are from it. Speaking to Tatum, he acknowledged the big differences in just little more than a decade.

"I didn't have the Internet in high school," Tatum recalled. "[I graduated in] '98. A ton has changed. I don't think I would even understand these kids anymore. I sound like I'm 50."

Hill is four years younger than his co-star, but was also aware of the seismic changes in teen culture. He, though, saw it as a source for comedy. "A lot of humor comes from us being out of touch. Even a few years out of school you immediately lose touch with what they're going through. It's mostly technology I would say. They live their lives on the computer and Facebook and everything. I just missed Facebook and all that stuff. We sound old."

Low expectations?

Another cultural disconnect is that kids today probably haven't seen the Fox series on which the movie is based. But for those who have, there's even an in-joke about how Hollywood retreads old television shows into movies without much imagination.

"We make fun of how lazy it is to remake or adapt things," Hill said referring to a scene early in the film. "For me it was the idea of adapting a TV show was just so lame, but I loved this story. And I think having low expectations of a movie based on a TV show is one of the best things about the movie. You go in with basement expectations, but this movie kicks ass. You leave going, 'Wow, I was not expecting it to be good and it's pretty good.'"

The title remains "21 Jump Street" because that is the name of the high school undercover program to which the pair is assigned. However Tatum thinks the title is inconsequential.

"The studio feels more comfortable when there's a title with a built-in audience," Tatum said. "But I think you could put 'Narcs' as the title of this and it would be the same. It wouldn't change the movie whatsoever."

Tatum - film’s big surprise

For many cop movies, actors ride along with real police officers as research. The '21 Jump Street' boys did not. "The whole point is we're supposed to be bad cops," Tatum cited as the reason.

Hill added, "The whole point is we haven't had the experience that real cops have had. So going on a ride-along would've been counterproductive because we fantasize about what it's actually like. We think it's just like riding around a park."

Goofing off on the job and playing a desperate high schooler are things audiences know Hill can do. They will be pleasantly surprised to see Tatum do the same.

"I think the great surprise of the movie is how great Chan is as a comedic actor," Hill said praising his co-star. "I think that's the thing you go into this movie not knowing much about. I like going into movies being doubtful of certain elements (such as an actor's ability to do comedy) and then seeing this guy crush it for an hour and a half. You're like, 'Wow, I didn't expect that to happen.'"

Tatum is responsible for delivering some of the film's funniest lines and comic bits, but he is also modest about his contributions. "I don't want people thinking that all the funny stuff came from going crazy and improvising because these guys really did write a great script," he explained.

Funny gunfights and car chases

And "21 Jump Street" is not just a buddy comedy, but an action comedy. The cops get into gunfights and car chases -- funny gunfights and car chases because they are so incompetent.

"My idea in the original script was to do a car chase in stop-and-go traffic," Hill said. "Because in movies the traffic is always moving at incredible speeds during car chases; but in real life there's lots of traffic. So to do a real highway speed chase you'd have to keep stopping and get out of the car and running around on the freeway, dressed as morons obviously." (In the scene, Tatum wears a geeky science project sweatshirt with molecule appliques and Hill is dressed as Peter Pan. Don't ask.)

Coming off of awards seasons for his Oscar nominated role in "Moneyball," Hill hasn't had time to write a follow-up to "Jump Street." Now that the film is about to open, Hill is thinking ahead. "I haven't had time to write," Hill said. "I mean, I've been pretty busy. But I'd love to (do a sequel). I think if all goes well, that's our ambition. Mike (Bacall) and I would start up again."

In all likelihood there will be: the film ends with the pair getting a new assignment - this time, impersonating college students - in the final frame.

Busy year

As for Channing, "21 Jump Street" is his third release of the year, following "Haywire" and "The Vow." But it is not the last: "G.I. Joe Retaliation" and "Magic Mike," Steven Soderbergh's film based on Tatum's experiences as a stripper, are still to come. Still, he hasn't been overwhelmed by such a busy year.

"I don't think you can be ready for it," Tatum said. "I think you just take it one day at a time. Truly, I actually don't even know what I'm doing tomorrow. I stopped trying to look into the future and be like, "all right, I've got this, that and the other thing'. Before I go to bed I figure out what I'm doing tomorrow. It's literally, just take it one day at a time."

But he paused to reflect on his good fortune. "I'm so lucky. It's crazy, an embarrassment of riches for sure."

"21 Jump Street" opens Friday.