From The TV IV
A spinoff is a program that uses characters or explicitly borrows the premise from a previous show, in order to capture the existing audience. Spinoffs take several different forms:
- One or more popular secondary characters will be written off of their show in order to be given a lead role in a new show (i.e. Joane Cunningham and Charles "Chachi" Arcola from Happy Days to Joanie Loves Chachi, or Angel from Buffy the Vampire Slayer to Angel).
- A popular show reaches its conclusion, and one or more characters move on to be featured in a new show (such as Frasier Crane from Cheers to Frasier, or Joey Tribbiani from Friends to Joey).
- A popular show's premise is essentially duplicated, usually with new characters in a new locale, this is sometimes referred to as franchising (CSI to CSI: New York, Law & Order to Law & Order: Special Victims Unit, or any of the Star Trek series).
- An episode of a popular show will introduce a completely new set of characters in a new situation to gage audience interest in a possible new show. If interest is high enough the new show can be greenlit this is called a backdoor pilot.
- See the list of spinoff series.