Matthew Mcconaughey needs to find a "launchpad line" in a movie before he takes on a role.

The ‘Sing 2’ star needs to figure out what “represents” how any character would react - and have a solid understanding of them - in any given scene before he can take on a job.

In an interview on KIIS 1065’s ‘The Kyle and Jackie Show’, the 52-year-old actor said: "I've said no to scripts if I did not either have inherently, what was written, find ‘the launch pad line’ or theme or something that I knew my character could have in their pocket from beginning to end and every single scene."

However, it not being put there by the writers does not automatically deter the Academy Award winner from taking on a role.

The ‘Dallas Buyers’ Club’ actor explained to hosts Kyle Sandilands and Jackie Henderson: “And sometimes the lines not written. Sometimes I'll come up with it and I’ll either put it in the movie, or I won’t put it in the movie, and I'll just remember it, but I look for a lyric.”

If the ‘launchpad line’ is missing, the ‘Magic Mike’ star will wonder what is the character’s mission or band.

Matthew - who is married to Camila Alves, the mother of his children Levi, 13, Vida, 11, and Livingston, eight- will ask: “What's the album cover? What's the title of the album, you know, for the character?"

"What represents, what line would represent in every scene, no matter what’s going on, I know my character’s about this.”

During the conversation, Matthew admitted to considering himself a "movie star".

He said: "I've been doing it for 32 years and have made over 50 something films. [I am] an actor, celebrity, movie star and a storyteller."