History Radio / TheHitchhikersGuideToTheGalaxy

It started with only two seasons in 1978-1980. It was later mixed-and-matched into the first two novels. It was later revived in 2003 and spawned three more seasons based on the last three books by Creator/DouglasAdams.

** [[IdiosyncraticEpisodeNaming Idiosyncratic Season Naming]]: Primary Phase, Secondary Phase and Tertiary Phase, while idiosyncratic, make sense as a sequence.
*** Quandary Phase and Quintessential Phase, however, do not complete the pattern formed by the first three. The names were chosen because they are "less daunting, more memorable and are a bit easier to spell" than the correct Quaternary and Quinary.

* [[spoiler:EverybodyLives: All the core cast manages to survive at the very end of the series, including Trillian and her alternate self (who merge into a single being), Marvin (who was still under warranty when he expired), and Fenchurch (who had been waiting at Milliway's since she seemingly ceased to exist). And the Vogons fail to eradicate every Earth.]]

* MessageInABottle: Arthur and Ford are stranded on prehistoric Earth, and attempt to attract the attention of a passing spaceship by waving a towel at it. A volcano then erupts, covering the towel with lava. When the Earth is blown up six million years later, the now-fossilized towel gets launched into space and found by Zaphod Beeblebrox in the spaceship Heart Of Gold, who travels back in time and rescues them. (Things like this tend to happen whenever you use the Heart Of Gold's "Infinite Improbability" drive.)

** A cloning machine accident results in a large number of clones of a young woman named Lintilla. The company's clean-up plan involves an equally large number of attractive male clones and a set of "Agreements to Cease to Be" disguised as marriage certificates.

* Zaphod, played by Mark Wing-Davey, was written as such [[{{Typecasting}} specifically because he was played by Mark Wing-Davey.]]
* Also Mark Smith, who just happens to play Hig Hurtenflirst!

* LargeHam: Zaphod, played by Mark Wing-Davey, was written as such [[{{Typecasting}} specifically because he was played by Mark Wing-Davey.]]

* InUniverseNickname: Marvin is first dubbed "The Paranoid Android" in Fit the Fifth, where he's parking cars at Milliways.

* FaceDeathWithDignity: As Zaphod, Trillian and Marvin are being eaten by the ravenous Bug Blatter Beast Of Traal:
-->'''Trillian:''' Aaarrgghh, it's got us! If I ever survive this, I'll get a job as Moby Dick's dentist!\\
'''Zaphod:''' Can it Trillian, I'm trying to die with dignity.\\
'''Marvin:''' I'm just trying to die.

* AndroidsArePeopleToo: Marvin the Paranoid Android was a prototype for robots fitted with Genuine People Personalities. He's never forgiven the Marketing Division of the Sirius Cybernetics Corporation (who defines a robot as "Your plastic pal who's fun to be with) for it.

* TakeThat: Shooty and Bang Bang, the two trigger-happy but sensitive cops who go after our heroes on Magrathea, are a cruel parody of series/StarskyAndHutch.

* TrickedIntoSigning:
** The Frogstar Prisoner Relations Officer pretends he wants Zaphod's autograph to trick Zaphod into signing a release form agreeing to be shoved into the Total Perspective Vortex.
** A cloning machine accident results in a large number of clones of a young woman named Lintilla. The company's clean-up plan involves an equally large number of attractive male clones and a set of "Agreements to Cease to Be" disguised as marriage certificates.

* {{Retcon}}: The entire Secondary Phase is AllJustADream Zaphod had, to cover for the Tertiary Phase opening with Ford and Arthur still being stranded on prehistoric Earth. [[spoiler: Subverted when Zaphod reveals it ''did'' all happen. Inside Zarniwoop's office. [[MindScrew Meaning the time in the Secondary Phase spent in Zarniwoop's office was inside Zarniwoop's office.]]

* CastingGag: Geoffrey Perkins, Douglas Adams's boss at the BBC, plays Arthur Dent's boss at the BBC.

* RemakeCameo: Inverted--cast members of [[Series/TheHitchhikersGuideToTheGalaxy the remake]] play roles in the continuation of the original series:
** The Quintessential Phase series had Sandra Dickinson, Trillian in [[Series/TheHitchhikersGuideToTheGalaxy the TV version]], voice Tricia [=McMillan=] (Trillian's alternate universe counterpart).
** David Dixon, the TV Ford Prefect, also had a cameo in the second episode of the Quandary Phase, getting pissed off at Arthur for trying to donate to save the dolphins when he should know they've all vanished. (This case is lampshaded, as Arthur--still played by Simon Jones, who acted alongside Dixon in the TV series--asks if they've met before.)
** Chris Langham, Arthur Dent from the 1979 Institute of Contemporary Arts stage production of ''Hitchhiker's'', pops up as Prak in the finale of the Tertiary Phase.
** StephenFry, the [[Film/TheHitchhikersGuideToTheGalaxy film's]] Guide, as Murray Bost Henson.

* ActingForTwo: Bill Wallis plays both Prosser (the man in charge of demolishing Arthur's house) and Jeltz (the alien in charge of demolishing Arthur's planet).

* MovingBuildings: The [=h2g2=] building in which Zaphod and Marvin have taken refuge - this is bodily uplifted by the dread Frogstar Fighters and transported through space to the world of the Infinite Perspective Vortex. En route, Zaphod is exposed to the terror of the Alien Disco.
** And also, the scene where Arthur and Ford are first exposed to the Infinite Improbability Drive. They briefly visit the holiday resort of Southend-on-Sea, Essex. Where the sea remains steady as a rock but all the buildings on the seafront roll up and down, like waves.

* ChekovsGun: Arthur mentions in Fit The Fifth he has a travel Scrabble game on him. [[spoiler: He and Ford use this to find out the question hidden in his brain waves in the next fit.]]