7 Little Known Tics That Defined Jared Leto's Joker Performance

5. He Went Off Script

As well as committing to his method to a frightening degree and refusing to rehearse his scenes with the rest of the cast to capture some authentic reactions, Leto also injected some of his scenes with his own touches.

According to Common, who shared the strip club scene with him, they were encouraged to improv their interaction. And Leto himself has revealed that he was basically a law unto himself while shooting scenes - which definitely does seem to come across in the behind-the-scenes footage:

“The Joker just goes completely nuts. He doesn’t wait to ask permission if he can say or do something. That’s really exciting. It keeps everybody on edge, including myself. I never know what I’m going to do next, I’ll be honest. I made a promise to myself that I was going to be as brave as possible, not be afraid to fail and to take a lot of chances on this movie. And I tried to stick to that.”

Leto not knowing what to expect from his OWN performance adds a volatility to the performance that really comes across in his interactions with other characters. They positively bristle when he's around, particularly in one-on-one situations and it genuinely adds a sense of unease.