Though many filmmakers consider it sloppy story construction, the Voice Over has been a standard in screenwriting since the early days of sound filmmaking. Voice Over is an easy way for one of the characters, or a distant narrator, to explain the thoughts and motivations of different people and help explain things that happen.
This can work as long as the Voice Over has a unique character and is not used to fill the gaps where the screenwriter could not figure out how to illustrate subtleties to the audience. Just as with different types of vocal description in the screenplay, there is a specific formatting that is unique to Voice Over.
Proper Voice Over Use
The first thing that you must make sure of when writing Voice Over in your screenplay is that you are not using the Voice Over for actual spoken dialogue. Many people think that someone talking off screen when it is still audible is a Voice Over, but it is not.
Occasionally, people use Voice Over formatting for phone dialogue that can be heard when the person is not on screen, and this is alright as long as it is clear that it is over the phone.
When you have a Voice Over situation you are simply going to separate this dialogue section from the rest and indicate that it is Voice Over. You do this just by adding a VO to the dialogue piece so that the reader understands this immediately. Example:
He still didn’t know that he was being watched from behind the car.
This piece of dialogue just needs to be separated from any back and forth or spoken word dialogue that is happening so people do not get confused. This should not be hard when the Voice Over is accompanying montages, second unit, or non-voice scenes, but when the internal monologue of a speaking character comes into play you may have a tough time.
Make sure you put at least one to two lines in between the Voice Over and any screen direction or dialogue that is spoken out loud. If the character is in the middle of the scene and goes from Voice Over to speaking out loud, you need to indicate this clearly. The key point in all screenwriting is that you just need to be clear to the reader what you are communicating, so once you write in your Voice Over scenes make sure another person reads it and can indicate exactly what is Voice Over and what is not.