The cast of 'The Super Mario Bros. Movie' on how improv shaped their characters

The Super Mario Bros. Movie has the full might of Nintendo's most famous characters behind it, but if that's not a strong enough selling point, the film has also assembled a cast full of A-list talent to voice those characters. And to sweeten the deal even more, many of the film's stars are comedy icons with a background in improvisation and a sense of play, all of which became a part of the film's dynamic. 

Speaking to Universal Pictures publicity at the Super Mario press junket earlier this month, stars Chris Pratt (Mario), Jack Black (Bowser), Keegan-Michael Key (Toad), and Seth Rogen (Donkey Kong) discussed the importance of improvisation when it came to building their characters, and to building the creative environment of making the film. 

RELATED: Keegan-Michael Key on how a friend (and helium) inspired his 'Super Mario Bros.' Toad voice

"I had a lot of leeway to improvise and to colloquialize, and that's sort of the beauty of this medium," Pratt said. "They're just rolling audio, and you can just say a million different versions of the same line. You know what the character is trying to say, and so you can say what's written, you can say what's not written to attempt to get that meaning across. And really, you just throw a million things at the wall and see what sticks."

Black, known for his comedic chops in everything from Tenacious D to Kung Fu Panda, saw improvising as an attempt to play beyond the borders of the script, and was sometimes surprised at what landed in the final film.

"I would always do the lines as written. That's the pro job, you gotta do it as written, give them what they want," Black explained. "And then at the end I would always be like, 'Hey, can I try another take, just for fun?' And they'd be like, 'Of course.' And that's where I'd do some stuff that was maybe a little edgier, maybe a little crazier, and a lot of stuff that obviously is not going to make it in the movie, but I just want to try it, just for fun. And sometimes that stuff does make it in the movie."

Key, whose career includes Mad TV and Key & Peele, took things even further as Toad, making up an entire song on the spot to go with his character.

"I tried to stay on the page as best as I could, because this movie, the story and the plotlines are very lean and very exciting in and of themselves," he explained. "But I was given a lot of leeway to improvise. In fact, it kind of ended up on the cutting room floor, but I ended up improvising an entire song for the movie where Toad gets to go on an adventure, which he's been waiting for his whole life. So I got to actually improvise his little adventure song, and that was a lot of fun."

Then there's Rogen, whose knack for offering variations on scripted interactions has been shown off in everything from Knocked Up to Superbad, who was able to really find a certain freedom in playing Donkey Kong from a voiceover booth. 

"They encourage it, especially with voiceover," Rogen said. "It's so easy to try different stuff, and you're the only there, so if it's not good you're not wasting 200 people's time. You're wasting like three people's time. It's really like a free and open creative environment, which is one of the reasons I like it so much. It's a lot easier to try a ton of different stuff on one line in a voiceover film than it is a live-action film."

So, how much of the film is improvised and how much of it is delivered exactly as it was written? We might never know, but you can see the blending of the two in action today, as The Super Mario Bros. Movie is in theaters now. Get tickets here!

Want more Illumination goodness in your life? Despicable Me and Despicable Me 2 are now streaming on Peacock.