Plot dump or exposition is a term used by the movie and television industries to describe a plot device by which critical elements of the plot, often involving the back-story, are not depicted directly but are instead elaborated in dialogue by one of the characters or by a narrator.

The term is usually invoked in a derisive sense. Although plot dump at the beginning of a movie is often tolerated as necessity for setting the premise of the plot, for example in such widely-acclaimed movies as Casablanca and Star Wars, plot dump expressed by characters in dialog during the course of the movie is often taken to be indicative of an inferior narrative. Examples of the latter sense often take the form of one character explaining elaborate details regarding another character that would seem exaggerated and out-of-place in real-life conversation. Villains are frequently given to making speeches about their sinister plans to helpless heroes, often prefacing their exposition with the comment that it can't hurt to divulge the plan, since the hero will be dead soon anyway.

A stereotypical and exaggerated example of inferior plot dump would be:

Joe: Who's at the door?

Mary: Oh, it's my uncle, who was released from prison yesterday after serving ten years for stealing the family jewels from this very house, although the jewels themselves have never been found and rumored to be buried in a secret chamber guarded by the ghost of my late grandmother!

Plot dump tends to be more tolerated on television than in the movies because the narrative of television episodes is shorter. Plot dumps are especially common in sit-coms in the introduction of non-recurring characters which drive the comedic plot of a particular episode.

In television sketch comedy, which itself borrows heavily from the tradition of Vaudeville comedy, plot dump in the most exaggerated sense is often used explicitly for outrageous comedic effect. In this case, plot dump is not seen as a weakness but as a standard and necessary aspect of the genre which is expected by audiences.

The Austin Powers film series has a character named Basil Exposition whose job was to repeatedly plot dump as a parody of the process in ordinary movies.