In episodic television, a bottle episode is produced cheaply and restricted in scope to use as few non-regular cast members, effects, and sets as possible. Bottle episodes are usually shot on sets built for other episodes, frequently the main interior sets for a series, and consist largely of dialogue and scenes for which no special preparations are needed. They are commonly used when one script has fallen through and another has to be written at short notice, or because of budgetary constraints. Bottle episodes have also been used for dramatic effect, with the limited setting and cast allowing for a slower pace and deeper exploration of character traits and motives.