A fake Shemp is a type of body double who appears in a film to replace another actor or person, usually when the original actor has died or is otherwise unable or unwilling to reprise their role. Their appearance is disguised using methods such as heavy make-up (or a computer-generated equivalent), filming from the back, dubbing in audio and splicing in past footage from the original actor's previous work, using a sound-alike voice actor, or using partial shots of the actor.
Coined by film director Sam Raimi, the term is named after Shemp Howard of The Three Stooges, whose sudden death in 1955 necessitated the use of these techniques to finish the films to which he was already committed. Although using fake Shemps was somewhat common throughout the 20th century, Screen Actors Guild contracts ban reproducing an actor's likeness unless the original actor gave permission to do so, largely because of a lawsuit filed by Crispin Glover—following his replacement by Jeffrey Weissman in Back to the Future Part II—that determined that the method violates the original actor's personality rights. The method continues to be used in cases, such as Shemp's, where the original actor is deceased and permission from the deceased actor's estate is granted.