The Hitchhiker's Guide to the Galaxy is a science fiction comedy series created by Douglas Adams. It debuted as a radio comedy broadcast on BBC Radio 4 in 1978. Since then it has been adapted to other formats, slowly becoming an international multi-media phenomenon over a span of several years. Adaptations have included stage shows, a series of five books first published between 1979 and 1992 (the first of which was titled The Hitchhiker's Guide to the Galaxy), a 1981 TV series, a 1984 computer game, and three series of three-part comic book adaptations of the first three novels published by DC Comics between 1993 and 1996. There were also two series of towels, produced by Beer-Davies, that are considered by some fans to be an "official version" of The Hitchhiker's Guide to the Galaxy, as they include text from the first novel. A Hollywood-funded film version, produced and filmed in the UK, was released in April 2005, and adaptations of the last three books to radio were broadcast from 2004 to 2005. Many of these adaptations, including the novels, the TV series, the computer game, and the earliest drafts of the Hollywood film's screenplay, were all done by Adams himself, and some of the stage shows debuted new material written by Adams.
The title The Hitchhiker's Guide to the Galaxy is often abbreviated as "HHGTTG", (as used on fan websites) or "H2G2" (first used by Neil Gaiman as a chapter title in Don't Panic and later by the online guide run by the BBC). The series is also often referred to as "The Hitchhiker's Guide", "Hitchhiker's", or simply "." This title can refer to any of the various incarnations of the story of which the books are the most widely distributed, having been translated into more than 30 languages by 2005. The title can also refer to the fictional guidebook The Hitchhiker's Guide to the Galaxy, an eccentric electronic encyclopedia that features in the series.
Although the various versions follow the same basic plot, they are in many places mutually contradictory, as Adams rewrote the story substantially for each new adaptation. In all versions, the series follows the adventures of Arthur Dent, a hapless Englishman who, with his friend Ford Prefect, an alien from a small planet somewhere in the vicinity of Betelgeuse and researcher for the eponymous guidebook, escapes the demolition of Earth by a bureaucratic alien race called the Vogons. Zaphod Beeblebrox, Ford's semi-cousin and part-time Galactic President, unknowingly saves the pair from certain death. He brings them aboard his stolen spaceship, the Heart of Gold, whose crew rounds out the main cast of characters: Marvin, the Paranoid Android, a depressed robot, and Trillian, formerly known as Tricia McMillan, a woman Arthur once met at a party who he soon realises is the only other survivor of Earth's destruction. After this, the characters embark on a quest to find the legendary planet of Magrathea and the Question to the Ultimate Answer.