* ''Marathon'' has several levels named after quotes from ''WesternAnimation/BeavisAndButthead'', such as the first level with lava being called "FIRE! FIRE! FIRE! FIRE! FIRE!," or the level with the first hidden flamethrower called "Smells like Napalm, tastes like Chicken!" "The Hard Stuff Rules..." seems to be another Beavis and Butthead reference, and "Couch Fishing" is another.
* ''Marathon'' level names are loaded with shout-outs... and bad Pfhor puns. Sometimes both at once. A complete discussion of level names can be found [[http://marathon.bungie.org/story/whatsinaname.html here]], but here are the main ones:
** "[[Music/TheKLF Never Burn Money]]" (probably a reference to "The K Foundation Burn a Million Quid")
** "[[Film/ApocalypseNow Smells Like Napalm]], Tastes Like Chicken"
** "[[Film/ForYourEyesOnly Pfhor Your Eyes Only]]"
** "MarsNeedsWomen"
** "[[Literature/WheresWally Waldo World Arena]]"
** "[[Franchise/StarWars You Don't Need to See My ID]]"
** "[[Film/BillAndTedsExcellentAdventure Waterloo Waterpark]]"
** "[[{{Theatre/Hamlet}} The Slings and Arrows of Outrageous Fortune]]"
** "Film/WhatAboutBob"
** "[[Literature/AliceInWonderland Curiouser and Curiouser]]"
** "If I Had a Rocket Launcher, I'd Make Somebody Pay" (Bruce Cockburn, ''[[ProtestSong If I Had a Rocket Launcher]]'')
** "[[Film/MillersCrossing Sorry Don't Make It So]]"
** "[[Music/TheB52s My Own Private Thermopylae]]" (while "My Own Private Idaho" was also the name of a [[Film/MyOwnPrivateIdaho film]], Matt Soell confirms that Jason Kirkpatrick probably named it after the B-52s song)
** "[[Film/MillersCrossing Where the Twist Flops]]"
** "Feel the Noise" (a reference to a song by Slade, CoveredUp by Music/QuietRiot)
** "[[Literature/{{Foundation}} All Roads Lead to Sol...]]"
** "[[Film/MadMaxBeyondThunderdome Thunderdome]]"
** "[[Film/TheEmpireStrikesBack No Disintegrations]]"
** "[[Film/PulpFiction OK, Honeybunny]]"
** "[[Film/ReturnOfTheJedi Lack of Vision]]"
** "[[Film/ArmyOfDarkness OK, Who Wants Some?]]"
** "[[{{Theatre/Hamlet}} Poor Yorick]]"
** "[[Literature/DoAndroidsDreamOfElectricSheep Electric Sheep One]]"
** "[[Franchise/StarTrek Where Some Rarely Go]]"
** "[[Film/BladeRunner Electric Sheep Two]]"
** "[[Film/ApocalypseNow Naw Man He's Close]]"
** "[[Literature/TheHobbit Foe Hammer]]"
** "[[Literature/TheRimeOfTheAncientMariner One thousand thousand slimy things]]"
** "[[Film/IndianaJonesAndTheLastCrusade A Converted Church in Venice, Italy]]"
** "[[Franchise/CthulhuMythos Strange Aeons]]"
** "[[Film/MadMaxBeyondThunderdome Beyond Thunderdome]]"
** "House of Pain" might seem like a reference to the group Music/HouseOfPain, or to Van Halen's song of the same title from their album ''1984'', or to the film "Film/IslandOfLostSouls" (itself inspired by Creator/HGWells' ''Literature/TheIslandOfDoctorMoreau'') instead, or to Music/OingoBoingo's "No Spill Blood", which is directly inspired by the film. However, it is none of these; [[http://marathon.bungie.org/story/levelcredits.html#10 according to its creator, Tuncer Deniz]], it is actually a take-off on Music/ThePolice's song "King of Pain", which was also used verbatim as the title for another level:
*** "[[Music/ThePolice King of Pain]]"
** "[[Music/TheFugees 'Fugee Camp]]"
* In "Rise Robot Rise", Tycho says, "Don't sweat the details, little monkey. Leave the strategizing to those of us with planet-sized brains", a clear reference to ''Literature/TheHitchhikersGuideToTheGalaxy'', in which Marvin complained, "Here I am, brain the size of a planet, and they ask me to take you to the bridge. Call that job satisfaction? 'Cos I don't".
* The "I am a hero" terminal is generally regarded to be a ShoutOut to Creator/MichaelMoorcock's Eternal Champion.
* ''Tempus Irae'' level shout-outs include (most of these explicitly confirmed by their creators):
** "Ain't My Bitch" - named after a song from Music/{{Metallica}}'s ''Load''
** "Gates of Delirium" - named after a song from Music/{{Yes}}' ''Relayer''
** "Downward Spiral" - named after Music/NineInchNails' ''Music/TheDownwardSpiral''
** "Brain Damage" - named after the song from Music/PinkFloyd's ''Music/TheDarkSideOfTheMoon''
** "The Revealing Science of God" - named after a song from Music/{{Yes}}' ''Tales from Topographic Oceans''
** "Never Satisfied" - named after a Music/JudasPriest song
*** "What's in a Name?" - a number of sources; originally a ShoutOutToShakespeare (it's in ''Theater/RomeoAndJuliet''); it's also the name of a game show (which the level creator claimed as the source of the puzzle name) and a section on the Marathon's Story page.
** "You Gotta Sin to Get Saved" - album by singer-songwriter Maria [=McKee=]
** "KMG-365" - a reference to the TV show ''Emergency Squad 51''
** "Mt. Vesuvius 2 - Electric Boogaloo" - play on ''Film/Breakin2ElectricBoogaloo'' (and of course a case of OddlyNamedSequel2ElectricBoogaloo)
** "For Your Eyes Only" - named after the Franchise/JamesBond [[Film/ForYourEyesOnly film]]
** The sequel ''Tempus Irae II: The Lost Levels'' itself is a reference to ''VideoGame/SuperMarioBrosTheLostLevels'', one of the most infamous cases of NoExportForYou, MissionPackSequel, and SequelDifficultySpike - fitting in the latter two cases as it includes the same textures and is quite a bit harder than the original ''Tempus Irae'', though not to the point of PlatformHell as the ''Mario'' game was (except maybe on the highest difficulties).[[note]]The ''Mario'' game was originally released in Japan as ''Super Mario Bros. 2'', but not released in other territories until much later. ''Every'' re-release until 2007 (when the original was ''finally'' released outside Japan on the Wii's Virtual Console) had its difficulty nerfed in some way. The game known as ''VideoGame/SuperMarioBros2'' literally everywhere else is a completely different game, originally released in Japan as ''Yume Kōjō: Doki Doki Panic'' (Japanese script: 夢工場 ドキドキパニック, figuratively meaning ''Dream Factory: Heart-Pounding Panic''; ''doki doki'' is a Japanese onomatopoeia for a heartbeat); it was released with a few gameplay changes as a DolledUpInstallment of the Mario series everywhere else, and became so popular in this form that it was ultimately re-released as ''Super Mario USA'' in Japan.[[/note]]
** "Prison Sex" - named after a Tool song
** "This Is the First Day" - named after the first line of Music/NineInchNails' "Wish"
** "Big Man with a Gun" - another Music/NineInchNails song, from the aforementioned ''Music/TheDownwardSpiral''
** "I Do Not Want This" - yet another Music/NineInchNails song, also from ''Music/TheDownwardSpiral''
** "It Was a Dark and Stormy Night" - named after one of the most infamous and frequently parodied opening lines in literary history, appearing in Edward Bulwer-Lytton's novel ''Paul Clifford'', and later in ''Literature/AWrinkleInTime'' and countless ''ComicStrip/{{Peanuts}}'' strips.
** "Epicus Doomicus Metallicus" - named after what's probably Music/{{Candlemass}}' most famous and influential album