There is a scene in the movie where DiCaprio slams his hand down very, very hard on a table, causing him to cut his hand on broken glass. This was not actually supposed to happen, but since he stayed in character, the directors and editors of the film left it in because it added substance to the scene.
Actors have a tough job, even though most may not think so. These actors sure take their job seriously with an absolute commitment to their craft. So, go ahead and see the actors who didn’t break character even after being injured during filming.