In fiction, continuity is consistency of the characteristics of persons, objects, places and events seen by the reader or viewer. The term is taken from the mathematical sense of something being smooth and without break. In some forms of media, such as comic books, continuity has also come to mean a set of contiguous events, sometimes said to be "set in the same universe".
Continuity is particularly a concern in the production of film and television due to the difficulty of rectifying an error in continuity after shooting has completed, although it also applies to other art forms, including novels, comics and animation, though usually on a much broader scale. Most productions have a script supervisor (formerly "script girl") on hand whose job is solely to pay attention to and attempt to maintain continuity across the chaotic and typically non-linear production shoot. This takes the form of a large amount of paperwork, photographs, and attention to and memory of large quantities of detail. It usually regards factors both within the scene and often even technical details including meticulous records of camera positioning and equipment settings. All of this is done so that ideally all related shots can match, despite perhaps parts being shot thousands of miles and several months apart. It is a less conspicuous job, though, because if done perfectly, no one will ever notice.
Many continuity errors are subtle, such as changes in the level of drink in a character's glass or the length of a cigarette, others can be more noticeable, such as changes in the clothing of a character. Such errors in continuity break the illusion of watching actual events. Care towards continuity must be taken because films are rarely filmed in the order they are presented in: that is, a crew may film a scene from the end of a movie first, followed by one from the middle, and so on. The shooting schedule is often dictated by location permit issues. A character may return to Times Square in New York City several times throughout a movie, but as it is extraordinarily expensive to close off Times Square, those scenes will likely be filmed all at once in order to reduce permit costs. Weather, the ambience of natural light, cast and crew availability, or any number of other circumstances can also influence a shooting schedule. There are two main types of continuity errors.
Visual errors are instant discontinuities. These errors only occur in visual media such as film and television. Items of clothing change colors, shadows get longer or shorter, items within a scene change place or disappear.
One example of a visual error occurs in the 1998 film Waking Ned Devine , when two of the films characters, Jackie and Michael, are walking through a storm towards Ned's house. The umbrella they are under is black during their conversation on the walk towards the house (filmed from slightly above and to the front); yet after cutting to a lower shot from behind Jackie approaching the house, Michael walks onscreen from the right holding an umbrella that is not black but beige, with a brown band at the rim.
Plot errors can occur in any media from film and television, to novels and radio dramas. They reflect a failure in the consistency of the created fictional world. For example, a character might state he was an only child, yet later mention having a sister. For dramatic purposes, sometimes a character on a show may have a friend who appears solely to illustrate a controversial issue to the audience. This plot device occurs often in what critics and television viewers alike have termed as very special episodes.
Continuity can become very complicated in fictional worlds that are vastly different from our reality, such as those found in science fiction or fantasy. Many universes, such as those in Star Wars or Star Trek, may be so well-known and detailed that it is difficult to create new stories that fit in the established timeline. Discrepancies in past continuity are sometimes made deliberately; this is known as retconning.
Frequently, film shoots will have one person dedicated exclusively to minding continuity. This continuity person will take detailed notes of timelines, placement of objects within scenes, wardrobes, and biographical references. The use of a Polaroid camera was standard but has since been replaced by the advent of digital cameras.
When continuity mistakes have already been made often explanations are proposed to smooth over discrepancies. In the original Star Wars, Han Solo, when boasting to Obi-Wan Kenobi about his ship the Millennium Falcon, claimed that he "made the Kessel run in less than twelve parsecs." A parsec is a measurement of distance, not speed. Later, in the Han Solo Trilogy written by A.C. Crispin , it was explained that the Kessel Run was a path through a black hole cluster, and the object was to skim as close as possible to the black holes, thereby reducing the distance travelled.
Other times the error is resolved by denying the existence of one of the offending tales. Deciding which stories officially make up a universe results in a canon. Discarding all existing continuity and starting from scratch is known as rebooting. A less extreme literary technique that erases one episode is called the reset button. Often when a fan does not agree with one of the events in a story (such as the death of a favorite character), he or she decides to simply ignore that the effect ever happened. This is known as Krypto-revisionism.