nondiegetic

Nondiegetic, also spelled non-diegetic, is a term used in film theory to describe elements that exist outside the world of the film’s narrative and are not perceived by the characters within the story. These elements are produced for the audience’s benefit, shaping mood, meaning, and interpretation without becoming part of the characters’ experiential reality.

Common examples include the musical score that accompanies scenes, which characters may not hear as music within the story world; off-screen narration that provides commentary or insight from an external voice; and on-screen text or credits that convey information beyond what characters would know. By contrast, diegetic elements originate in the film's world and can be perceived by the characters, such as dialogue, sound effects, or music that a character can hear.

Borderline cases occur when a sound or image can function both diegetically and nondiegetically depending on context; for example, a radio within a scene may be heard by characters (diegetic) but, when used as an audience cue, can also serve nondiegetic purposes. Filmmakers deliberately deploy nondiegetic elements to guide audience response, create irony, foreshadow events, or underscore themes.

Understanding nondiegetic sound and imagery helps differentiate how viewers are guided differently from the characters’ experience and how film form contributes to meaning. See also diegetic sound, sound design, film score, voiceover, and diegesis.