Adrian Brody gave up his apartment and car, and moved to Europe with just two bags to prepare for his role in The Pianist.
Jim Carrey mentally prepared to play Andy Kaufman so thoroughly that he continued Kaufman’s real life feud with Jerry Lawler and spat in his face.
Tippi Hedrin had live birds thrown at her by stagehands in preparation for the iconic attack scene in Alfred Hitchcock’s The Birds.
Clint Eastwood bought the rights for Unforgiven, and then waited 15 years before making the movie. He wanted to be old enough to convincingly play the lead role of William Munny.
Min-sik Choi burned himself with a hot wire to simulate the method with which his character counts the years in his prison cell in the film Oldboy.
While filming The Jacket Adrien Brody insisted on being locked inside a straight jacket and placed inside a morgue drawer in-between scenes.
Brad Pitt had his smile ruined to more convincingly play Tyler Durden in Fight Club. He had his two from teeth chipped, and then repaired after the movie finished filming.
James Franco accompanied a male prostitute while visiting johns to prepare for his role as a prostitute in the film Sonny.
Christian Bale lived on an apple a day to prepare for his “svelte” role in The Machinist and then put on 100 pounds of muscle to play Bruce Wayne in Batman Begins
Filming had to be stopped on Castaway so Tom Hanks could lose 50 pounds and grow his hair out to account for his time on the island.
Gary Oldman played so many American characters in a row that he had to see a speech therapist to regain his British accent.
To prepare for his role on Breaking Bad, Bryan Cranston actually learned how to make meth from the DEA.
Val Kilmer became so convincing in his role as Jim Morrison that the other members of the Doors could not tell who was singing in the film.
For his universally acclaimed performance as the Joker, Heath Ledger spent a month locked in a hotel room. He wanted to get in touch with how unpredictable a psychopath could be.
Denzel Washington arranged to be waterboarded to understand it better in the movie Safe House.
Chloë Sevigny performed oral sex on her co-star Vincent Gallo in the film Brown Bunny.
Daniel Day-Lewis caught pneumonia while preparing for The Age of Innocence. He walked around New York City for two months dressed in period specific clothing including a cane and a top hat.
Charlie Sheen took steroids so he could throw faster on camera in Major League.
Shia Labeouf decided that his sex scenes in Nymphomaniac needed to appear very real. So they were. He and co-star Stacy Martin had sex on camera. Shia’s then girlfriend left him soon after.
50-Cent lost 60 pounds to play a character suffering through chemo therapy in All Things Falls Apart.
Scott Glenn watched tapes recovered from actual crime scenes showing torture and murder to prepare for his role in Silence of the Lambs. He did not return for any of the sequels because he was still disturbed by what he had seen.
Robert De Niro did 12 hour shifts in a New York City cab for a month before he filmed Taxi Driver
Before filming for The Last of the Mohicans could start, Daniel Day-Lewis had to be located. He had disappeared for six months, later claiming that he had been living in the wilderness to prepare for his role.