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Some of the most classic film moments have been improvised or were outtakes, and one can imagine that comedy films like The Watch don't always stick to the script. Ben Stiller revealed to ET how closely he and his co-stars followed the original script of the upcoming film.

"There was a lot of improvisation in the movie," Stiller said. "The script was great and it was really funny, but you can't help [it] when you got guys like this where you just want to have some fun and liven it up."

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Stiller then comically described his co-stars' knacks for improvisation: "Jonah's pretty good at improvisation. He can make stuff up; he likes to spat it out...Vince has got a mind...really like a sieve, actually--a lot of stuff goes through it but the little things that do come through are nuggets of gold."

Although he and his co-stars swapped some words from the original script, Stiller's character, who is the most serious man in the Watch group, remained the same. The 46-year-old actor said he enjoyed playing the character of "Evan" despite his distinction from the group.

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"I feel like we each had...a pretty delineated character and Evan's the guy who...wants to keep everything in line and really takes it all seriously," he said. "It was fun to play that."

While Stiller and co-stars Vince Vaughn, Jonah Hill, and Richard Aoyade were willing to take a risk by improvising some of the film's lines, they revealed that everyone but Hill was not willing to put their body at risk by performing their own stunts.

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When the group was asked what they hope viewers will take away from the film, Hill responded matter-of-factly, "[I] just hope they laugh, have fun."

The Watch comes to theaters this Friday (July 27).