Downey Jr. says the film has a new take on the beloved character.
"The core quality is he's really dedicated. He's also pretty eccentric," said Downey Jr. "He has his own sense of justice, or whatever. We played around with all of the stuff the way Conan Doyle described them. We always tried to have them at least half rooted in that sort of stuff."
"We certainly done what we set out to do, which was marry an idea of taking this to a new audience, using cinema as a way of embracing the drama and the action of Conan Doyle's Holmes, but also going back and rediscovering material that had so far been perhaps left unchartered," said Law.
Law says many people won't recognize this new version on Holmes' sidekick Watson. "Watson's always had this persona of being portly and slightly idiotic and bumbling," said Law. "When you go back to the books he's just come back from Afghanistan, he's a decorated soldier and a doctor who's used to having blood on his hands. He's very much front and center in all the investigations and we've, I think, successfully put that color into our film."
Along with the new personas, the film also goes for a few laughs.
"We just figured that there was a lot of things that I remember in reading the text that were naturally humorous and Guy's got a pretty wild sense of humor, so it kind of found its way into the script a little bit," said Downey Jr.
"Sherlock Holmes," rated PG-13, also stars Rachel McAdams. The movie will hit theaters on Wednesday, Dec. 23.