A serial film, film serial, movie serial, or chapter play, is a motion picture form popular during the first half of the 20th century, consisting of a series of short subjects exhibited in consecutive order at one theater, generally advancing weekly, until the series is completed. Usually, each serial involves a single set of characters, protagonistic and antagonistic, involved in a single story, which has been edited into chapters after the fashion of serial fiction and the episodes cannot be shown out of order or as a single or a random collection of short subjects.

A cliffhanger or cliffhanger ending is a plot device in fiction which features a main character in a precarious or difficult dilemma or confronted with a shocking revelation at the end of an episode or a film of serialized fiction. A cliffhanger is hoped to incentivize the audience to return to see how the characters resolve the dilemma.