I have noticed that many films seem to depend on voice-overs, especially films adapted from novels, I worry about overusing voice over in my own script writing because it seems like a kind of compensation when one can’t write the action of a scene, or translate a character’s thoughts into a compelling visual. What guidelines would you suggest for writing voice-overs?
Voice-overs have a bad reputation for exactly the reasons you cite. Often, one senses that that writer didn’t do a good job finding visuals and dialogue to tell the story, and thus fell back on the voice-over as a crutch. And it’s an especially pervasive problem with movies based on books, because the voice-over is often the easiest way to translate prose to the screen.
My advice – nothing revolutionary – is to do everything you can to plan out your story without using any voice-over at all. That means creating scenes that give the important information while moving the story forward, and using images and moments in place of explanation.
But there are some instances where a voice-over is appropriate. BIG FISH, which I adapted from a novel by Daniel Wallace, uses voice-over extensively, because the movie is about unraveling the elaborate stories that a man tells. Since storytelling is at the center of the movie, it makes sense that characters will be narrating these tales, both on-camera and off.
What’s important is that voice-over should never replace actual scenes, nor should it be redundant to what we do see. If a character opens a box and finds a gun inside, the voice-over shouldn’t say, "When I opened the box, I found a gun inside." That voice-over adds nothing, except an explanation for the blind. But if the voice-over had said, "My uncle had many ways of keeping us in check," then you would have changed the dynamic of the scene in an interesting way.
Another important factor is which character is doing the voice-over. Whoever you pick will automatically get elevated to Most Important Character status unless you deliberately state otherwise (such as THE PRINCESS BRIDE, which is narrated by a character outside of the world). Just make sure that whoever gets voice-over power is worth the investment.
Finally, a pet peeve. In my opinion, movies should either use voice-over throughout or not at all. If a movie starts with a voice-over, then never uses it again, I get frustrated waiting for it to come back. Similarly, a voice-over that just kicks in at the end is bewildering, because it seems to break the rules of the movie I just watched.