James Mangold believes the R rating afforded to 'Logan' has been key to the movie's success.

James Mangold

James Mangold

The 53-year-old director - who previously helmed the much-maligned 'Wolverine' in 2013 - has revealed that he and Hollywood star Hugh Jackman pushed to create a more adult movie so it would avoid the conventions of a typical superhero film.

He explained: "I knew that if Hugh and I could get an R, then we'll have the freedom to make an adult film.

"Because the second the marketing arm of a studio realises it cannot market to children, five or six creative things happen. The scenes can go deeper, and can be written for adults. Not just language, not just [violence], as you're saying, but the themes can be more interesting, the words you're using can be more complicated. The ideas can be more complicated."

He said, too, that the movie's R rating means there is less pressure to fill 'Logan' with the sort of gimmicks that can create merchandising revenue.

James told Den of Geek: "Also, the film comes under no pressure to be a platform for the sale of toys. Because there's going to be no kids to see it."

Meanwhile, Hugh - who has now played the iconic character for the final time - previously said 'Logan' has more depth to it than previous Wolverine movies.

He shared: "I love Wolverine. I will not miss it, for it will always be inside me.

"It was very emotional to make this movie. I always felt that there was a deeper story about this character.

"I'm very proud of the movies of the past, but I felt I had something more. Like a man. He did not want to be just the tough Wolverine, but the difficult Logan.

"I cried a few times on the set. I hope fans will say: finally, this is the Wolverine movie I wanted to see."