Acting isn't always a pretence. Some performers don't just show up on set and spout their lines. Some movie stars utilise The Method; a technique where they "become" the character they are portraying. Even if the camera isn't rolling, they won't drop the character's accent or mannerisms. They may not even respond to their real name. They can be so connected to their work, it's hard to draw the line between the actor and the character.
The reason why some performers practice this technique this is simple: authenticity. If you're playing an alcoholic, it would look more real if you got drunk, right?
There is some logic to this. Many Method actors have won all sorts of accolades for their devotion to their work. Performers like Daniel Day-Lewis have earned a name for themselves by utilising this famous acting tool.
But that doesn't mean you can't go too far. Some actors have gotten so invested in their scenes, they have injured themselves, attacked others, and derailed entire productions. You have to admire these actors for taking their craft so seriously - but that isn't always a good thing.
12. Daniel Day-Lewis - There Will Be Blood
There is no actor more famous (or infamous) for using The Method than Daniel Day-Lewis. The British actor spent time in jail for In the Name of the Father, didn't bathe for The Crucible, and boxed professional fighters for The Boxer. And for his Academy Award-winning performance as the oil merchant, Daniel Plainview, in There Will Be Blood, he spent nearly the entire production in character.
Although the reports that his intensity encouraged an actor to quit the production are unfounded, there is no question DDL went too far. Paul Dano, who played Eli, confessed he genuinely thought he might die while filming because he could never predict what his co-star was going to do. In certain scenes, the three-time Oscar winner would smack Dano unscripted or earlier than he was meant to so his reaction would be more authentic.
While filming the climax, Dano admitted he was "scared for my life" while Day-Lewis hurled real bowling balls and pins at him full-force. Dano is a talented performer but little acting was required for this scene. All the terror on his face during the final moment was 100% genuine.