The Joker is one of those characters actors would give anything to portray. It seems thought, it was a massive undertaking for every actor who portrayed him in the past. Everyone wanted to meet the high expectations that came with playing this character.
YouTube Channel ScreenRant produced a video about the preparation those actors took to play The Joker.
In 1989, in Tim Burton’s Batman, Jack Nicholson became The Joker. The role was made for him and suited his acting style well. Nicholson didn’t have to do any special preparation. Michael Keaton once said, when he and Nicholson sat in their costumes and waited to go on set,, “We just gotta let the wardrobe do the acting, kid.”
Later when Heath Ledger was announced to play The Joker, people where really critical of him and didn’t expect him to do a good job. He spent a lot of time preparing, for example he locked himself in a hotel room for a month and wrote a journal as The Joker, to better understand the supervillian’s mindset.
A month after the first trailer dropped, he died of an overdose. Despite this tragedy, and the controversy around it, those who worked on set of The Dark Knight said Ledger had a great time playing the character and that The Joker was just a role.
When Jared Leto played the part, he never broke character on set, and sent his fellow actors disgusting gifts as The Joker. He became the character in real life and on the screen. Unfortunately, the character went in a weird direction in the movie which people didn’t really like.
What you recognize first when you see Joaquin Phoenix’s Joker is that he has lost a lot of weight for it, around 52 pounds (25 kilos). It was the director’s decision to have a skinny Joker, Phoenix wanted him to be fat. He also read books about political assassination and watched videos of people suffering from pathological laughter.
If you want to see more on how actors prepared for The Joker give the video a watch.