Deadpool screenwriters Rhett Reese and Paul Wernick tell Collider the film will indeed break the fourth wall. For years, the character has been addressing the reader, and sometimes the writer, with his opinions of the plot in various Marvel comics.
"Deadpool obviously breaks that fourth wall in the comics, he breaks it in the movie," said Wernick. "We do have our fun with the Wolverine movie and how Deadpool was portrayed, and yet we completely disregarded it and done it hopefully better than they did."
"The comics had given us the lead way to break the fourth wall, so in a way he's just strangely omniscient," added Reese. "He can talk about the fact that he's in a movie, he can talk about things that the character wouldn't know and everyone around him is kind of like, 'What are you talking about?'"
While maintaining Deadpool's understanding that he's a fictional character, the writers decided not to go as far with the mental instability that has become a feature of his comic book counterpart. "It's not the hearing voices, we're not doing that, he's not schizophrenic or anything, but he is as Ryan [Reynolds] says, in a highly militarized shame spiral," said Reese. "We're not pushing him quite as far as some of the later comics do in terms of his sheer insanity. We figured we had time to do that, hopefully with sequels we have time to do that."
Deadpool opens on February 12th, 2016.