Seth Rogen and Evan Goldberg have been behind some huge summer comedies in the past, but with "This Is The End," the longtime writing partners are behind the camera for the first time, making their directorial debut. And to ease the transition, Rogen and Goldberg enlisted the help of some of their famous friends like James Franco and Jonah Hill to play fictionalized versions of themselves in the apocalyptic comedy. As you might have guessed, this essentially translates to cracking dick jokes and ragging on each other's movies while waiting out the end of the world. Because even after all Hell breaks loose, it's never too late to make fun of "The Green Hornet."

Inspired by a short film Rogen and Goldberg helped make back in 2007 ("Jay and Seth Versus The Apocalypse"), "This Is The End" is a disaster movie for the "Superbad" set, which means it's as foul-mouthed and funny as anything else the guys have done. And when the duo came to Toronto to promote the film, Moviefone sat down with the Vancouver natives to talk about making their directorial debut, developing the movie's anatomically-correct monsters, and which cast member had the thickest skin.

Did you guys write this script with an eye to direct it?
Evan Goldberg: Yeah. When we made the short, there was no intention to direct it whatsoever. And then over time, we kept talking with Jason Stone, who made the short with us, about doing some apocalypse thing, and then we had our idea to have stars play themselves. And when we realized that together they would be great, and that our six guys would be the best guys, we were like, "Well, who would be the best director?" And that was the first time ever where we were like, "Maybe us?"

Seth Rogen: We couldn't unleash these guys on someone else. [Laughs] It wouldn't be fair.

Goldberg: Yeah, it was the only way to justify it. We're the only people who could actually get these six guys and we thought it was important that it be these six guys to do it.

What was that dynamic like, working with your friends? Would one of you have to be the adult in the room getting everybody to work?
Goldberg: It would actually usually be Seth, since he's in the middle of it with the guys. Because I'd be over there at the monitors and be like, "Guys, come on! F---ing get your s--t together!" They can't even hear me, and they can easily ignore me, but Seth's right in the room being like, "Settle. Settle. Guys, settle."

Rogen: Yeah, I would say "Settle" a lot. That was my word. I was like, " 'Settle' is code for 'Shut the f--- up and start acting.' " I was very upfront with that. That was the subtext there.

Goldberg: And eventually we realized if you just say "Action!" they have to show up. Just start rolling the cameras.

Rogen: There's like a Pavlovian thing.

There are so many great cameos during the initial party scene. How did you decide on people like Rihanna and Aziz Ansari, and was there anyone you wanted to cameo that you couldn't get?
Goldberg: There were some people we couldn't get just due to scheduling issues. Liz Banks, Edward Norton, but when it came to casting the parts, we'd written bits. We had the six main characters and we crafted the film for them. With the other celebrities, we made a bunch of bits, then we talked to them, "Well, what would you like to do? We got this bit you could do."

Rogen: We just wanted it to feel organic though. We wanted it to feel like a real party. And at a real party, there are generally some people where you're like, "Why are they here?"

Goldberg: Like, Seth had a Halloween party and Quentin Tarantino showed up.

Rogen: Yeah, exactly. And David O. Russell was there. It was like, "Who invited [them]? I've really never even met these people!" So we wanted to add that element where it feels organic and real, but at the same time, there's a few curveballs in there.

Goldberg: Our only rule was keep it young. Even though, in reality, 50-year-old dudes showed up to your party.

Rogen: Yeah, we want it to seem real and feel like hypothetically people were getting a glimpse inside a possible version of what one of these parties is actually like.

Did you write a lot of the self-deprecating jokes in the script, or did that come out of improvisation more?
Goldberg: We got the ball rolling in the script and really let the actors take it further.

Rogen: I think, if anything, the guys were more antagonistic with each other than we wanted. [Laugh] We'd often have to stop Jonah [Hill] and [James] Franco from going at each other and be like, "You guys like each other in this movie. We get it, you can make 'Moneyball' jokes all day. In this movie though, you guys wouldn't be doing that."

Goldberg: They would get lost in it, because they were having fun. They would enjoy slamming each other.

Rogen: It's true, people would just wrapped up in the joy of being able to make jokes slamming their friend's movie.

So who has the thickest skin?
Goldberg: Franco.

Rogen: Definitely Franco, yeah.

Goldberg: Franco has, like, infinite thickness. There's nothing you can do to faze him.

Rogen: And the more you think it might be something that insults him, the more entertained he is by it.

Goldberg: I literally went up to him and was like, "I want to do an art project with you. Let's do an art project about how stupid your art projects are." And he was like, "Great! I love it!" You can't faze the guy.

Do you find it sort of odd how much James Franco's celebrity has taken off?
Goldberg: I think it's the awesomest, craziest, weirdest thing anyone's ever done. His whole schtick is the most amusing thing ever. I love it.

Rogen: Yeah, I think it's awesome. He really seems to be in control of it. People seem to be fascinated by it.

Goldberg: And he doesn't seem propelled by some deep need for something. He's just having a good time.

Rogen: Yeah, as people who are his good friends who see him in his natural day-to-day environment all the time, he really is just into that stuff. He actually thinks it's interesting. If anything, he's almost embarrassed to talk about it. Like, when we ask him about it, he's like, "Aw, you guys are just gonna make fun of it." [Laughs]

Goldberg: Yeah, he starts to blush.

Rogen: "It's stupid, it's this weird project where it's a film of me s---ting on a guy." But he's genuinely into it. When I met him when I was 16 years old, he was into it. I literally have a painting hanging on my wall that he painted for me in 1998. It's not a new thing for him. I think now he's more famous, so it gets more attention.

Goldberg: Yeah, if he hadn't become a famous actor, nothing would be different, just the amount of money he'd have towards these weird causes.

How much input did the guys have in terms of developing their characters?
Rogen: Some of it we went into with, and the guys really were instrumental themselves in coming up with a lot of it, I gotta say. Like, we always knew Jonah would get raped by a demon and possessed. [Laughs] We just knew that's what we wanted to happen.

Goldberg: Not in context of the film, just in life.

Rogen: Exactly, just in life. We were very honest with Jonah. We were like, "This is where we want it to end."

Goldberg: That was the one thing, and if you're not OK with this, then we have a problem. He's like, "No, I'm fine."

Rogen: But the guys themselves had a lot of input, and I think because they were playing themselves, they didn't care if they played bad versions, they just wanted to be interesting.

Goldberg: Like Franco added the idea that he's in love with Seth, which would've been a demented thing for Seth to add.

Rogen: Yeah, exactly, you can't pitch that as the filmmaker: "How about you love me?"

Was it hard toning Danny McBride down then?
Rogen: [Laughs] In real life, Danny's like the sweetest, nicest guy.

Goldberg: Danny's the funniest. When it comes to public perception, Danny's the one where it's just like everyone's got it wrong. He crafted Kenny Powers off of people he didn't like.

Rogen: And now it's who he's associated with.

So what's the bigger disparity from real life then, Michael Cera or Danny McBride?
Rogen: Probably Michael Cera.

Goldberg: I don't know. Danny's character is really far from him. Danny's never tried to kill us.

Rogen: Michael does own that windbreaker. [Laughs]

What made you settle on doing the Biblical end of the world as opposed to a more generic apocalypse?
Rogen: The overall thought was, what if they were right? What if all The Book of Revelations was right? How would it go?

Goldberg: And we like to talk about how no one can get mad at us for what we've done here. The people who think that's gonna happen, we're just doing what you think's gonna happen.

Rogen: The original draft of the script said, "Based on the book by God." We didn't send it out like that though.

Goldberg: We should've.

Rogen: But to us it was really, it was almost the craziest part of the movie. And it was honestly the part that we expected to meet the most resistance on. We thought if the studio has one thing they'll fight us on, it's the fact that we're tackling religion head-on.

Goldberg: And they didn't say a damn thing.

Rogen: They literally never said anything about it. They didn't care about that at all. It was all whether or not we should play ourselves. That was like every conversation we had with them.

Can you talk a bit about how you developed the look of the monsters?
Goldberg: When it came to the monsters, we, in our amateur director move, did what everyone does. We were like, "We're gonna use real s--t, we're not gonna use computers." So we constructed suits, and the whole time, the VFX guy, he kept looking at us. And we were like, "You don't think this is gonna make it into the movie?" He's like, "Just do what you want, it's fine. I budgeted for this. Don't worry."

Rogen: And then you watch it and you're just like, "Yeah, it's a dude in a suit running around chasing us."

Goldberg: Society's gone so far towards CG that in my head we could do some Guillermo Del Toro s--t, but only he can. And even he's making giant CG monsters now. So it's over. CG.

Rogen: We wanted them to have a classic kinda hellish look.

Goldberg: But obviously with a bit of...

Rogen: With dicks. [Laughs] It's funny. At first, we didn't give the big monster a dick. And then we gave him a little dick, and then we were like, "Eh, just give him a big giant dick." [Laughs]

Who modeled it?
Goldberg: Someone in Montreal. God, I'll never forget, we came into the visual effects house one time, and they were like, "No, no, it should be like..." [swings his arm around]

Rogen: [Laughs] Yeah, they were acting it out. "Floppier!" was a direction we gave a lot. We'd always talk to our effects house over the phone because they were in Montreal and we'd always be like, "Floppier!"

Goldberg: And they were so obsessed. They were like, [in a French accent] "A penis would not go like this! It would not!" And we're like, "Just make it f---ing floppier, guys!"

Rogen: "Who cares?! Make it floppier! It's much better."

"This Is The End" opens in theatres on June 12.