10 Behind The Scenes Reasons For Harry Potter Character Traits

Given that the Harry Potter movies began production before J.K. Rowling completed writing the novels, there was the potential for storytelling inconsistency if the cast members weren't kept apprised of what Rowling had in store for their characters.

This was especially true of Severus Snape, who in the final book, Deathly Hallows, is revealed to have been a double agent working against Voldemort the entire time.

But Rowling had planned out Snape's arc years in advance, and so was able to hint to Snape actor Alan Rickman early on that his character's true motivations were different than they seemed - he was actually working as a protector of Harry all along.

This allowed Rickman to give a more complex and layered performance, where Snape's apparent dislike of Harry could still be plausibly masking his true intentions.

Had Rowling simply not told Rickman early on about Snape's real nature, Rickman would've understandably doubled down on Snape's callousness to the point that the subsequent twist could've come off as inauthentic.

Rickman even had to stand firm against directors who gave him notes on his performance, assuring them that he was aware of the wider narrative and made acting choices with respect to that.

Of Rowling's decision to clue him up on Snape's arc, Rickman said:

"[It] helped me think that he was more complicated and that the story was not going to be as straight down the line as everybody thought. If you remember when I did the first film she'd only written three or four books, so nobody knew where it was really going except her. And it was important for her that I know something, but she only gave me a tiny piece of information which helped me think it was a more ambiguous route...

What I knew was he was a human being and not an automaton... I knew there was some sense of protection for Harry or I worked that out. It was enough to know, I didn't know he was a double agent."