Practical effect

A location shot for The Black Dahlia with a rainmaking rig, a sprinkler system used to create the appearance of rain—a common practical effect

A practical effect is a special effect in which a prop appears to work in a situation where it obviously could not in real life (such as a ringing telephone on stage). They do not use trick photography or post-production techniques. This type of effect is normally found in live theatre.

In film, practical effect denotes an effect produced on-set, without computer-generated imagery. Special effect is often synonymous with practical effect. In contrast, visual effects are created in post-production through photographic manipulation or computer generation.

Many of the staples of action movies are practical effects. Gunfire, bullet wounds, rain, wind, fire, and explosions can all be produced on a movie set by someone skilled in practical effects.

Christopher Nolan is a modern filmmaker noted for his preference of practical effects over computer-generated effects. Many of the effects used in his action films, including The Dark Knight and Inception, are practical.