Voice-over

Voice-over is spoken narration heard over the picture rather than from someone visibly speaking on screen, used to supply a perspective the image cannot.

The working rule is short: voice-over must counterpoint the image and add depth or conflict to it. Voice-over that describes what the audience is already watching is bad voice-over, and the fix is to cut it rather than rewrite it — the picture was doing the job.

Counterpoint is what earns the device. A narrator whose account contradicts what we see, or reframes it, or knows how it ends, gives the scene a second layer the camera cannot supply. That is why the narrator with a personality of their own tends to work and the neutral explainer does not; the same thing that makes an unreliable narrator interesting in prose is what makes voice-over interesting on screen.

Against that, the reader's default assumption is worth knowing. Unless voice-over is organically part of the story's presentation — Fight Club being the usual example — it reads to script readers as a lazy device, most often as exposition being poured over footage that should have carried it.

The honest test is to delete every line of it and read the sequence again. Whatever the scene still needs is the voice-over worth keeping.