Filler

In television, filler refers to episodes in a continuity-based series that are not required to understand the basic story arcs. Fans often believe that filler episodes have been made to pad out a weak story, especially if they are perceived to be of poor quality. However, filler episodes are sometimes used to give background to characters and events, or to give writers a chance to show off creativity and deviate from the standard mood of the series. The most common type of filler episode is a 'character episode' which focuses on the backstory or motivations of a single character. Such episodes are useful in series which have large ensemble casts who cannot always be featured simultaneously.

Filler is tolerated to a certain degree by fans. Common complaints about filler episodes may include contradictions to the main storyline, OOC situations, and events or characters which should have a larger impact of a storyline but which are never brought up again. Filler is more apparent in series which producers are required to have a specific number of episodes per season.

Sometimes, filler material can be unexpectedly popular and even overshadow the main material. A major example was the creation of the characters Bob and Doug McKenzie of Second City TV fame. The characters were created to fulfill and ridicule CBC's request for 2 minutes of identifiably Canadian content on the show. However, the characters became the most popular on the show and the signature characters of it.