Film extra

A background actor or extra is a performer in a film, television show, stage, musical, opera or ballet production, who appears in a nonspeaking or nonsinging (silent) capacity, usually in the background (for example, in an audience or busy street scene). War films and epic films often employ background actors in large numbers: some films have featured hundreds or even thousands of paid background actors as cast members (hence the term "cast of thousands"). Likewise, grand opera can involve many background actors appearing in spectacular productions.

On a film or TV set, background actors are usually referred to as "background talent", "background performers", "background artists", "background cast members" or simply "background", while the term "extra" is rarely used. In a stage production, background actors are commonly referred to as "supernumeraries". In opera and ballet, they are called either "extras" or "supers".

Casting criteria for background actors depend on the production. It has been said that background cast members often require little or no acting experience. This is not entirely true, as any type of unrealistic portrayal must include some form of imagination and acting. Punctuality, reliability and the ability to take direction also figure prominently for these cast members. Background actors are often selected on short notice, after all other preparations for the shoot have been finalized.

Several casting agencies specialize only in background work, whilst in the UK the directory Contacts published annually by Spotlight list all accredited agencies and productions. Some agencies charge a registration fee, and some (mostly commercial background casting) will take between 10% and 15% commission from any booked worked. Artists may be required to provide a basic one-page A4 sized CV/resume, that states basic personal details and dimensions, any significant skills (e.g. stage combat), and includes two 8x10 inch photographs on the rear: one head shot; one full body shot.

When hiring background actors, casting directors generally seek those with a specific "look", such as "high school students" or "affluent senior citizens", consistent with the context of the film. Casting directors may also look for background actors with a special skill for the scene, such as rollerblading, or dancing. A background actor is often expected to bring his or her own wardrobe to the set, although there are also "fittings" for a specific scene or period. A casting director may favor the one who already has the required costume or prop, such as a police uniform, or a musical instrument. On other occasions, where a costume has already been prepared (for example, to fit another actor who is now unavailable), a background actor may be selected as a "costume double" simply because they are the right size to fit it. On smaller productions or student films, background actors may be hired en masse with little formality.

...
Wikipedia