The stars and supporting actors are rarely the only performers in a film. Most films also use extras, who perform small non-speaking roles, often as part of a crowd. Many films also require stunt performers to execute potentially dangerous physical actions, such as catching fire. Some performers work as doubles, imitating an actor who is unavailable, and are often filmed in long shot or from a rear view. Stunt doubles can be used to create the illusion that an actor is performing his or her own stunts. Body doubles are used when an actor does not possess the required physical attributes or when a star refuses to appear naked. Other performers are not seen physically but are featured on the soundtrack. They include voice-over artists, who are used for spoken narration, and voice actors, who create the character voices in cartoons. Sometimes the voice of a live actor is replaced, a practice especially common when singing is required. The Hollywood star Rita Hayworth (1918–1987) had her "singing voice" recorded by other artists, including Nan Wynn (1915–1971), Martha Mears (1908–1986), Anita Ellis (b. 1920), and Jo Ann Greer (d. 2001).
Stand-ins do not appear in the final film, but have a very important function. During the preparation of a shot, when lighting is set up and camera movements are rehearsed, they replace the actors in order to allow the actors time for other preparations, such as makeup.