I've always heard, "Never use voice over in a script." At SXSW the panel moderator asked Sam Esmail when he chose to use VO in Mr Robot. “Right away,” Esmail said. “Do I talk to myself? That’s between me and my imaginary friend, but because Elliot didn’t talk to people, we had to use that screenwriting tool. Lots of people tell screenwriters not to use voiceover. Don’t listen to that. Many great films have VO.” Are there other "Never do that" rules that you break? Why do you do it? When is it OK to break the rules?