Good friends made 'This Is the End' into a real party

• An all-star cast including Seth Rogen%2C Jonah Hill and James Franco face the apocalypse in %27This Is the End.%27
• Each member of the cast had aspects of their personalities amplified as they played themselves
• The movie centers around a party at James Franco%27s house

CULVER CITY, Calif. — By a tape recorder's count, it takes 12 seconds for three stars of This is the End to lose it as they assemble to promote their latest comedy film.

Seth Rogen, Craig Robinson and Jay Baruchel are contemplating a comically small couch, with the latter two insisting Rogen take the center spot. "You are the director," Baruchel points out.

Rogen demurs, gallantly suggesting that he and Baruchel flank Robinson, who is black. "It will at least be more symmetrical," Rogen says, grinning devilishly.

All three howl with laughter. This is the type of off-color dynamic Rogen and his writing partner/co-director Evan Goldberg sold to Sony Pictures in order to get some $30 million to make the apocalypse comedy, opening Wednesday. Low humor is the key to the high-concept story: It's set during a party at James Franco's house, where a group of actors, playing heightened versions of themselves, fend off Judgment Day while trading one-liners.

Expanding on the concept from the 2007 short Jay and Seth Versus the Apocalypse, Rogen and Goldberg brought in famous faces from their past films and focused on "the funniest/lamest (things) about each of us, and then magnifying that exponentially to a comedic extent," says Baruchel, who worked with Rogen on 2007's Knocked Up.

"Everyone gets ripped apart in this movie," adds co-star Jonah Hill later by phone. His character is high on his post-Moneyball status (Hill was nominated for a supporting actor Oscar for the 2011 film), and shields his disdain for Rogen's oldest friend, Baruchel, under a guise of syrupy niceness. "I don't think anyone was safe from getting made fun of."

In the movie, Baruchel flies into Los Angeles to visit Rogen, who takes him to a blowout party at Franco's place. Rihanna's there, and so is a Michael Cera-obsessed Mindy Kaling.

Fans in the know will fixate on how the stars' personalities are amplified in the film: As monsters prowl a burning L.A.,, Franco is horrified that the guys would think to board up the windows with his prized artwork. Rogen is still the marijuana aficionado that everyone wants to befriend, and Danny McBride, who last worked with Rogen on 2008's Pineapple Express, is salty and boorish as ever, overindulging in the stockpiled food and defiling the last porn stash.

Meanwhile, Baruchel feuds with Hill as Robinson woos partygoers with a ballad entitled Take Yo' Panties Off.

Rogen says he and Goldberg allowed their friends to help shape their on-screen personas. That way, "they're personally responsible so they can't argue with you that much. 'You helped come up with this, man!' ''

He notes that each cast member petitioned for changes. "Literally everyone but Franco,'' says Rogen, who depicts the star sleeping in an eye mask and greeting guests in a Gucci outfit.

"That doesn't mean that the character was most like me," Franco jokingly protests, via Skype from a set in London. "It just means that I'm not vain about how I'm presented."

How exaggerated are the depictions?

"I love Seth and I love working with Seth, but I don't really need Seth's approval to complete my life like the character in the film does," says Franco. "I like art, but I would never value art over the safety of my friends. And my actual house is nothing like the house in the film."

Hill, who sports a diamond earring in the movie (he got the idea from Jamie Foxx while shooting Django Unchained), refutes the idea that he's more pretentious as a result of his recent success. "I don't think I've changed since Moneyball. I think I'm really lucky to get to do what I do and I'm really lucky to have had some success.''

All agree that McBride, absent today after missing a connecting flight, is the furthest from his infamously abrasive persona in the Eastbound & Down TV series. ("I think a lot of people think I'm like Kenny Powers, so this was kind of a way to push that persona even further, I guess," says McBride later during an after-party.)

And Robinson? "Take yo' panties off. That's what I do," The Office alum grins. "That's really me. That's what I'm bringing to the party, that's what I'm bringing to everyday life."

Rogen estimates that what ended up on screen was half scripted and half improv. How did such stars as Rihanna and Emma Watson fare with inventing dialogue on the fly? "Rihanna was, oddly, a little more comfortable with it because she had just maybe acted less in general, so she had less of a preconceived notion of what acting is like in a movie," says Rogen. "Emma was a little bit spooked at first."

It didn't help that Rogen and Goldberg scrapped the dialogue they'd written on her first day. "She was dropped in the middle of this crucible of fire of all of us,'' says Baruchel. "We're like 'What? What do you want me say? I'll say whatever you want!' It's daunting as hell."

Game as they were, even this crowd occasionally drew a line in the sand on the set in New Orleans.

There was a Mother Teresa joke Evan pitched, and I was like 'Please don't make me,' " says Robinson.

"There was something about Canada or hockey they wanted me to say that I didn't want to say, about how much I actually hate both things,'' says Baruchel. "And I said, 'I can't.' I couldn't do that."

Adds Rogen: "Danny didn't want to moon the camera. And I think he would have if we had warmed him up to it a little bit, but we just threw it at him in the middle of a scene. I think he just wanted some mental preparation."

Although End openly treads on the ridiculous, in an age of reality TV it's hardly a stretch to suggest that audiences could walk away swayed by the meta performances.

"I'm so unconcerned with that kind of thing," says Franco. "Of course there's a bit of me in a role that I do. But when it gets down to specific beliefs or activities — thinking that I'm a big pothead because I did Pineapple Express or thinking that I'm gay because I did Milk — I think it's a mild form of insanity to believe that those are who I am, when I'm obviously playing characters."

"Every interview you do, every movie you do, is an opportunity to show where you're at at that moment," adds Hill, taking the long view. "And this movie is so absurd and funny that I think everyone should just take it as it's a fun, funny movie with a bunch of funny guys."

"It's not like we're setting the record straight in this movie," says Rogen. "If anything, we're making ourselves stupider and worse. Maybe people will just appreciate that we're making fun of ourselves and that makes you seem a little more self-aware in general?"

Baruchel chimes in: "Or it makes douche bags douchier."

Rogen nods. "Or,'' he says, "it will make us seem like the most self-indulgent fools on the planet."