In Vince Vaughn's new heartfelt comedy, Delivery Man, Chris Pratt (Parks and Recreation) plays Vaughn's archetypal lawyer buddy, Brett. In the film the comedic pair fall on opposite sides of a moral dilemma on whether or not David Wozniak (Vaughn) should reveal his identity to his children - all 533 of them.

Delivery Man tells the story of a seemingly ordinary man who finds himself in an extraordinary situation when a clerical error results in Wozniak becoming the genetic father of a 533 kids, many of whom are suing to find out who their father (codenamed 'Starbuck') is. The lawyer (Pratt) hands Vaughn's character the legal documents with profiles on all of the kids which throws him on a life-changing journey.

Written/directed by the Ken Scott, who brought us the French Canadian version, Starbuck, the film's unique storyline allows for some very comedic situations, many of which rely on the abilities of funnyman Chris Pratt. Pratt has starred in key supporting roles in Oscar-nominated hits including Zero Dark Thirty and Moneyball, and is currently most well-known for his regular role on the TV comedy, Parks and Recreation.

[gallery columns="2" ids="391892,391900"]

We had the chance to talk to Pratt who decided it was important for his character Brett - a single dad of four young kids - to look beaten up on life and out of shape, so he gained sixty pounds for the part. Immediately after the movie wrapped, he painfully lost seventy pounds to play Peter Quill, his biggest role yet in Marvel's upcoming Guardians of the Galaxy. And it isn't any surprise that Pratt is sworn to studio secrecy although we did shamelessly try to squeeze some juicy info about the highly anticipated plot.

-

What attracted you to the script?

Chris Pratt: Oh man, I was attracted to this movie primarily because of two things, Ken Scott as a film maker; I'm a huge fan of his work. I loved the original Starbuck, I think he's got a really interesting voice. He's doing something I haven't seen done before with this movie and Vince Vaughn is one of my favorite comedic actors. He's a huge movie star. I'm a big fan of his and have been ever since I even started acting. Those were both elements that really made me want to be a part of this.

Had you known Vince before shooting?

No, I had never met Vince before; I met Vince working on this movie.

So what is it like working with Vince? You convincingly play best friends in the film.

Vince is hard working. No nonsense. There were moments when we laughed so hard. He really had people laughing, but then there were other moments where it was like 'we're not messing around, we're working.' And I respect that.  I really respect that. We worked hard and played hard. We spent a good amount of time getting to know one another because we're supposed to be best friends in this and he took time out of his schedule so we could spend time together and get to know one another better.

Delivery Man Official Still Photo - Chris Pratt and Vince Vaughn

Any pranks on the set?

(Shakes head) No pranks on set. We were shooting in Brooklyn, New York, so every second was super expensive and you couldn't waste a minute.

You gained sixty pounds to play this role and your body isn't a stranger to going up and down on the scales…

Yeah…

Why did you feel the need to gain sixty pounds to play a lawyer?

Well, you're right.  You don't have to be fat to be a lawyer. What I think is this character is this despondent, emasculated man who was a lawyer but who has now been left to parent four children on his own.  To me it felt like he was depressed and I think that when you gain weight, for me there's a certain rhythm to your spirit that changes when you treat the vehicle you're in terribly.  When you eat terrible foods, when you binge eat and when you eat your emotions and all of that stuff, it reveals itself in the way you look. For me, I saw it as an opportunity to play somebody who is really depressed and I know that when I'm fat, I'm depressed. In the original, the brilliant actor who played Brett's role was a slightly bigger guy and I thought it really worked. There are scenes where my daughter is playing with my jowls. I'm wearing a bathrobe; I'm this disheveled fat masculine man. So I thought that would really work if I was big, I thought Brett would be less likable if he was super cut and he's talking about how he hates being a father and how he's depressed and how his mother doesn't love him. But he's the guy who wakes up and does sit ups every day. I wouldn't buy that.

And you lost weight for your next role in Guardians of the Galaxy

Yeah, I lost about seventy pounds.

Delivery Man Official Still Photo - Chris Pratt and Vince Vaughn

How tough was that? Is it harder to lose?

Losing weight as a lot of people in America and around the world know, it's difficult.

The word on the corridor is that you're not talking about anything Marvel. But we want to know, are you excited for the new film?

Oh, I'm so excited. I feel great about it. I can't wait. I'm really excited for people to see it and I hope they have fun watching it like we did making it. It was a really incredible experience.  I think it's going to be a great movie.

-

Chris Pratt can next be heard in The LEGO Movie and seen in Disney and Marvel's Guardians of the Galaxy.

A DreamWorks Pictures and Reliance Entertainment presentation, the film is written for the screen and directed by Ken Scott, based on “Starbuck,” the original screenplay written by Ken Scott and Martin Petit, and also stars Chris Pratt and Cobie Smulders. “Delivery Man” is produced by André Rouleau and executive produced by Ray Angelic, Scott Mednick and Mark Sourian.

Delivery Man hits theaters on November 22, 2013