[[quoteright:350:https://static.tvtropes.org/pmwiki/pub/images/81zqcl8ir_l.jpg]]
[[caption-width-right:350:''An Experiment on a Parallel Universe with the Windbags.'']]
->''"With magic you can turn a frog into a prince. With science you can turn a frog into a PHD and still have the frog you started with."''

''The Science of Discworld'', by Creator/TerryPratchett, mathematician Ian Stewart, and biologist Jack Cohen, is one half Literature/{{Discworld}} novel, in which the wizards accidentally create a universe without magic and are fascinated by the way it develops its own rules in the absence of NarrativeCausality, and one half popular science text, as Stewart and Cohen explain how the Roundworld Project (i.e., our universe) actually works.

It was followed by three sequels:

* In ''The Science of Discworld II: The Globe'', the wizards must stop TheFairFolk preying on the superstitious folk of Elizabethan Roundworld, while Stewart and Cohen talk about the nature of storytelling and belief.
* In ''The Science of Discworld III: Darwin's Watch'', the wizards must stop the God of Evolution from seriously confusing UsefulNotes/CharlesDarwin, while Stewart and Cohen discuss his theory in more detail than they had to spare in the first book.
* In ''The Science of Discworld IV: Judgement Day'', a sect of Omnian extremists start claiming Roundworld is evidence they were right all along about the shape of the world, and [[InsaneTrollLogic therefore]] it belongs to them, while a sceptical Roundworld librarian ends up on the Disc. Stewart and Cohen discuss the nature and practice of science, itself.

----
!!''The Science of Discworld'' series contains examples of:

* AgonyOfTheFeet: Trying to prevent the murder of Darwin, Rincewind winds up getting a cannonball dropped on his foot.
* AlternateHistory: Several in the later books, all of them ending with [[spoiler: humanity failing to invent the SpaceElevator before it's Giant Snowball Time]].
* AmbiguouslyRelated: In the second and third books, the men who (badly) fill the historical roles of, respectively, Creator/WilliamShakespeare and UsefulNotes/CharlesDarwin (until the wizards fix things) are named Arthur J. Nightingale[[labelnote:*]] who still exists in the final timeline, but as an illiterate ploughman[[/labelnote]] and ''Preserved'' J. Nightingale[[labelnote:*]] short for Preserved-By-God; he was the sole survivor of a shipwreck as an infant and his adoptive parents were extremely religious[[/labelnote]]. It's not outright stated that they are members of the same Nightingale family (keep in mind that they would have lived about 300 years apart), but given the similar roles they play in the story, the implication is there.
* AnswersToTheNameOfGod: The Dean, after creating the universe as we know it, responds to Ridicully's declaration of "Ye gods" with "yo?"
* ArcWords: Each book has several core concepts that keep being re-stated in different contexts. The first book has LiesToChildren and the "SpaceElevator", which is a metaphor for doing something in such a way that it makes subsequent efforts easier, like building a space elevator so that you don't have to keep expending massive fuel payloads to launch things into space, or how DNA allows lifeforms to make copies of themselves by cheaply copying their existing genetic information. The second book uses the "make-a-human-being kit" for the set of cultural traits and social norms that a tribe uses to control the development of its offspring, and keeps asserting that humans are not in the genus of ''homo'' but are instead ''pan narrans'', the "storytelling chimp".
* AsYouKnow: Zigzagged in the fiction portions, in which Ponder uses this phrase out of politeness when he suspects Ridcully ''doesn't'' know something about physics; this gives him the chance to contrast Discworld physics (which the ''readers'' don't necessarily know) with Roundworld rules (which readers ''might'' know, but Ridcully doesn't).
* AuthorityInNameOnly: Rincewind's promotion to Professor of Cruel and Unusual Geography is very much an excuse so the other wizards can dump him into Roundworld. The end of the book states that he's not allowed to teach or even get paid, but he can show up at meals, provided he eats very quietly.
* BeethovenWasAnAlienSpy: Creator/WilliamShakespeare and [[UsefulNotes/CharlesDarwin Darwin]], amongst others, are greatly influenced by the wizards.
* BewareTheNiceOnes: At one point in Book 2, all the wizards get duplicated due to time travel. Fixing this requires merging them, essentially killing at least one of the duplicates. Initially it seems like everyone is okay with this, only at the last second for them to turn on one another and try to punch themselves out (except the Rincewinds). The normally non-active Ponder is included in this.
* BiggerIsBetter: The Lecturer in Recent Runes' attitude to creating life that will withstand Roundworld's regular cataclysms - it's a limpet with a base a mile across, that ''eats whales''.
* BlobMonster: In the first book, Rincewind gets covered in morphless predatory life forms.
* BrickJoke: In Book 3, Ponder, when the topic of evolution rears its head, lives in dread of Ridicully trying to ask about the eye. Eventually, Ridicully does mention the eye, and Ponder yelps in alarm. Fortunately, he's not asking about it. He figures eyes are easy. Now, the ''wasp'', on the other hand.
* CallBack:
** During ''Literature/ReaperMan'', a footnote on the High Energy Building noted that one day the older wizards were going to be very nervous when they learned just what it was the students were wanting to build on the squash court. Sure enough, the story begins with the students having finally built a Thing on the squash court, and the older wizards ''are'' nervous.
** Remember Death's speech in ''Literature/{{Hogfather}}'' about how humans need fantasy to be humans? That idea plays a large part in the second book.
** The wizard's scheme in book 2, inspired by Granny Weatherwax, is based on what she threatened the Elf Queen with back in ''Lords and Ladies''.
** Rincewind is still obsessed with potatoes and still tends to associate them with sex. When the Elf Queen tries to seduce him, he asks her if she can give him potatoes.
-->'''Elf Queen:''' Do you not think I could give you something better than a potato?
-->'''Rincewind:''' [[ComicallyMissingThePoint Are we talking about sour cream topping with chives?]]
** In Book 4, Ridcully pulls the exact same gag on Vetinari that Ponder Stibbons did to him in the very first volume, having the Patrician ceremonially "activate" UU's latest MagiTek device despite the fact that they'd already turned it on earlier to make sure it would actually work.
* CapitalLettersAreMagic: Early in Book 3, there's a bit on Very Big Things, an important part of any university faculty (if only because they keep students out of mischief).
* ChekhovsSkill: The Luggage's ability to travel between worlds in pursuit of its master debuted in ''Literature/TheColourOfMagic'' and was expanded upon in ''Literature/{{Eric}}''. This ability is finally put to practical use in book II.
* ColonyDrop: Happens repeatedly in the first book, once ([[ButtMonkey of course!]]) right on top of Rincewind.
* ContinuityNod:
** The first book once again brings up the wizard fondness for SchmuckBait, this time via the metaphor of guillotines. Put a sign up near one saying not to put your head in one, and wizards would never need to buy a hat again.
** One of first non-fiction chapters paraphrases Death's speech to Susan from the end of ''Hogfather'', noting you could grind the universe down to its component parts, and still not find a single atom of Science.
** In order to demonstrate how un-magical Roundworld is, Ridicully bellows out eight repeatedly, and nothing happens. Doesn't stop the wizards cowering in fear.
* TheConstant: In the timelines in which Darwin fails to produce ''The Origin of Species'', Richard Dawkins eventually does, suggesting that he is an evolutionary biologist in every possible timeline.
* CowTools: It is mentioned that every University has a Very Big Thing, whose primary purpose is to be bigger and more impressive than the Very Big Thing owned by the school's rival University. UU's VBT is apparently a distinct item from Hex and the Roundworld, and only gets brought up in a budget meeting where the senior wizards are discussing if they need to make it even bigger to outdo Brazeneck University's.
* CreatingLifeIsUnforeseen: The wizards had just been throwing planets together. Actually creating life hadn't been their intention. Likewise, the Dean hadn't meant to create a universe. In that instance, Hex speculates that he'd just given the nothingness a little nudge it was looking for to really exist.
* CreativeSterility: What mankind is like without the elves interfering. No drive, no ambition, no imagination. No ''humanity''.
* DeadGuyOnDisplay: Rincewind is alarmed to see that Elizabeathan London has heads on spikes.
* DesperateObjectCatch: Rincewind drops the glass globe containing Roundworld when the Bursar pops up suddenly, then just barely catches it with a DivingSave. Something similar happens in the fourth book when Marjorie chases a zealot who has stolen Roundworld and, when he is cornered, he throws it at her.
* DestinationDefenestration: Some Omnians are thrown out the window in the fourth one.
* DifferentWorldDifferentMovies: When they write that intelligence appears to be useful enough that it would probably still have arisen is some form if we hadn't appeared (the fiction parts show a number of civilisations getting a foothold on Roundworld in much earlier epochs, only to be wiped out by cataclysmic disasters) they speculate that if sentient crabs had evolved on the Earth in humans' place, three of them might be writing ''The Science of Dishworld'', about a bowl-shaped world that's carried on the backs of gigantic marine invertebrates.
** In-universe, the third book is about the wizards' attempts to ensure that Charles Darwin writes ''On The Origin Of Species'', not ''Theology Of Species''.
* {{Dissimile}}: While discussing a blob-like prehistoric life form, one of the wizards uses the phrase "dead man's shoes", then reflects that the blobs don't have feet, aren't smart enough to invent shoes, and don't have anything to make shoes out of.
* EarlyBirdCameo: Roundworld itself, as Rincewind and Twoflower briefly travel there in ''Literature/TheColourOfMagic''. The Librarian briefly encounters Darwin in the first book.
* ExactWords:
** What are the chances of Ponder's thaum-splitting magical reactor "just blowin' up and destroyin' the entire university?" None at all. If it goes up, it won't just blow up the university - it'll destroy the entire city, or even the Discworld.
** In vol 2, Ridicully asks Hex to take the wizards to someone considered a genius among genius. Hex takes them to Isaac Newton's basement, but since it's Newton during his later years, the wizards only find his alchemy notes, and decide then and there he's a nutcase not worth bothering with.
** Also in book 2, Hex tells Rincewind and Ponder that it can get the wizards out of Roundworld. Rincewind thinks carefully about this, and asks if it means ''alive''. Hex pauses before saying yes, so Rincewind makes sure to ask alive and ''intact''. When it is determined that they might be a little damaged, the two wizards go for another way to get them.
** When discussing the works of Arthur J. Nightingale, who writes not-quite-there versions of Shakespeare's plays, Hex says he is considered the best artist of the time. But objectively speaking, he's utter crap.
* {{Expy}}: Ratonasticthenes for Eratosthenes, and Antigonus for Archimedes.
* TheFairFolk: In volume 2.
* FamousFamousFictional: The beginning of the first book has a series of epigraphs, including Arthur C. Clarke, Mark Twain, and finally... Ponder Stibbons.
* TheFinalTemptation: In vol 2, the Fairy Queen tries to tempt Rincewind into giving up on helping mankind. Her efforts fail because, as established back in ''Interesting Times'', Rincewind's sole desire is potatoes (he be perfectly happy with a bag of crisps, even). The Fairy Queen is utterly baffled by this.
* {{Foil}}: Rincewind and Ponder are foils to each other in the scenes they share together. Both are rational men, but in different ways. Ponder is a realist who relies on facts, but also very optimistic about the cause of science and progress, while Rincewind is more intuitive and cynical, being a lot more experienced about how efforts at progress usually turn out.
* FootnoteFever: Aside from the usual ones, early on in one of the non-fiction segments of the second book, it's stated that, in essence, the non-fiction parts of the book are extended versions of footnotes.
* {{Foreshadowing}}: In the first book, several pre-human intelligent civilizations arise on Roundworld, only to be wiped out by asteroids or other disasters. After the demise of the dinosaurs, one of the wizards comments that a ''really'' intelligent civilization would get off the planet as soon as possible. [[spoiler:In the end, human civilization escapes disaster by doing just that.]]
* ForWantOfANail:
** The numerous events that prevent Shakespeare or Darwin from producing their works in alternate Roundworld timelines.
** Hex also mentions how, in 1734, a German shoemaker named Joshua Goddelson left his house by the back door, setting in motion a chain of events that (somehow) leads to commercial fusion power in 2017.[[labelnote:*]] Since that year has now passed and commercial fusion power is still not viable, we must sadly conclude that we are living in the timeline where he left by the front.[[/labelnote]]
** In the universe where Arthur J. Nightingale wrote ''Macbeth'', it's A: A comedy, and B: ''Much'' shorter, since Macbeth decides not to listen to the witches at all.
* TheFundamentalist: The Omnian fundamentalists in the fourth book are so close-minded that they remain convinced only they know the True Word of Om [[spoiler: even when the god in question manifests specifically to tell them to stop being idiots]].
* GainaxEnding: The first book ends with a giant, unliving turtle being spontaneously constructed in Roundworld space. "Recursion Is Occurring."
* GiverOfLameNames: The elves are pretty impressed by Shakespeare's writing (though they're not sure about the "girdle around the earth in three minutes" thing), but one of them - an impossibly old one who's seen and done a lot - thinks maybe after hearing the name "Peaseblossom" that humans maybe aren't worth bothering with.[[labelnote:*]] Though, funnily enough, ''Literature/TheShepherdsCrown'' would reveal that the elves do, in fact, have a Lord Peaseblossom among their number -- and a Lord Mustardseed too, for that matter. Chalk that one up to alternate pasts.[[/labelnote]]
* GivingUpOnLogic: At first, the Wizards try to build a world using Discworld-logic, but after numerous failures, eventually Ponder Stibbons has a moment of BreakTheScientist and determines that the only way to get anything done is to understand what rules Roundworld runs on.
* GoneHorriblyRight: The Thaum Reactor was built for the purpose of creating more heat for the University in winter (The Senior Faculty were lukewarm on the subject of knowledge, but boiling hot when it came to frosty windows). The reactor ends up working too well- just before Hex channels the excessive magic into the Roundworld Project, the college becomes so hot that Ridcully dreams he's lost in a broiling desert, only to find reality no different in temperature.
* GotVolunteered: How Rincewind becomes Egregious Professor of Cruel and Unusual Geography in the first place; he's dragged in front of the assembled senior wizards and told he can't refuse the job, nor can he resign. Happens again at the end of the first book. He's told that while, yes, going into the High Energy Magic building, which is filled with ludicrous and potentially deadly amounts of energy, is dangerous, it's not as dangerous as not going might be, hint hint.
* HowDidYouKnowIDidnt: Happens when the Dean sticks his hand into the nascent Roundworld project:
-->"That was a really very foolish thing you just did," said Ridcully. "How did you know that it wasn't dangerous?"
-->"I didn't," said the Dean cheerfully. "It feels... cool. And rather chilly. Prickly, in a funny sort of way."
* HumansAreTheRealMonsters: On being defeated at the end of Book 3, the Auditors warn Charles Darwin and the Wizards that all they have done is created a timeline in which humanity will spread war and destruction across the entire galaxy. Darwin is a little disconcerted by this, but Ridcully's reaction, rather predictably, is essentially to shrug his shoulders and say "so what?"
* IRejectYourReality: [[TheFundamentalist Reverend Stackpole]] in ''IV'', who remains firmly wedded to the Omnian church's ancient (and [[Literature/SmallGods long-since abandoned]]) doctrine that [[DoesThisRemindYouOfAnything the Disc is a sphere despite overwhelming evidence to the contrary]]. Even when his god appears in person and ''straight-up tells him to his face that he's wrong'', Stackpole simply refuses to acknowledge this, insisting that his "concept of the true being of Om" has more validity than the real thing.
* IncrediblyLameFun: Rincewind's first appearance in book 2 has him sorting rocks (which the previous incumbent of the position of Professor of Cruel and Unusual Geography had left unsorted). Since it's utterly dull, Rincewind's having a whale of a time.
* InDefenceOfStoryTelling: The whole of book 2. Humans need stories to be ''human''.
* INeedToGoIronMyDog: When Ridicully tries discussing the evolution of the wasp, Ponder declares he can hear the lunch bell going off, and he'd better go check it right now.
* InSpiteOfANail: Apparently, if Darwin had become a believer in what we'd now call "intelligent design", UsefulNotes/RichardDawkins would have been the author of ''The Origin Of Species'', sadly too late to make a difference. So Dawkins would be a Darwinist even if Darwin wasn't.
* InterruptedSuicide: Rincewind repeatedly puts a fish back into the water, not realizing it's adapting to life on land rather than trying to kill itself.
* InsultToRocks: In book III, Ridicully notes that Ponder's explanations are so easy first that even ''wizards'' can understand them, and later, professors.
* ItWillNeverCatchOn: The wizards do this a lot, first claiming that planets are no place for life, that the sea is only place for a intelligent creature, that the primates will never amount to anything, and so on.
** Also, that the "terribly dull lizards" would never catch anyone's interest, such that any accounts of Roundworld prehistory will most likely skip over their era.
* JerkassHasAPoint:
** In the one of the science chapters in the first book, the narration notes that Rincewind's speech on how meaningless it is to build a life on Roundworld is with its tendency to destroy any civilization with giant snowballs and other disasters, while we might find it harsh, makes sense. Rincewind has seen the Roundworld on a far grander scale than any native has, so while we might enjoy living on it ''at the moment'', the same could be said about the dinosaurs. Just ask them; ''You can't, can you. That's the point.''
** Late in the first book, as the wizards ruminate on Roundworld's history, Rincewind makes a cutting remark. Ridicully curtly informs him "that remark was incredibly cynical and accurate".
* LiesToChildren: The TropeNamer. In the fiction sections, Ponder describes his thaumic reactor to the other faculty using Lies-To-Wizards, and Hex's reports mainly consist of Lies-To-People.
* LiteraryWorkOfMagic:
** ''II: The Globe'': The wizards of Unseen University visit the "Roundworld" to fight off the elves as they disrupt ''Theatre/AMidsummerNightsDream''.
** ''SOD III: Darwin's Watch'': The wizards try to make sure that UsefulNotes/CharlesDarwin completes ''The Origin of Species''
* LogicBomb: Ridicully manages to inflict one of these on a mass of Auditors at the end of Book III.
* MageInManhattan: The Series! from the creation of Earth all the way to the modern day.
* MagicVersusScience: The Roundworld Project's original intention was to create a place where magic could not exist, which was thought to be impossible.
* {{Magitek}}: Hex of course, and the Thaumic Engine is the magical equivalent of a nuclear reactor (going back to Pratchett's roots, as he made many similar comparisons in ''Literature/TheColourOfMagic'').
* MondegreenGag: Discussed in one of the science sections in the second book, when they bring up how our brains fill in the blanks in our sensory data by putting what we have seen and heard in a context.
-->This is why we can get the words of songs completely wrong and not realise it. The ''Guardian'' newspaper ran an amusing section on this habit, with examples such as "kit-kat angel" for "kick-ass angel" -- bit of a generation gap there, which underlines how our perceptions are biased by our expectations. Ian recalls an Annie Lennox song that really went "a garden overgrown with trees", but always sounded like "I'm getting overgrown with fleas".[[note]]Amusingly enough, ''he's still wrong''. The actual lyric is "I'm thrown and overblown with bliss".[[/note]]
* TheMonolith: Parodied with the Dean's chalkboard-assisted lesson to the apes.
* MythologyGag: Among the quotations at the beginning of the third book is Preserved J. Nightingale's version of Paley's "watch" quote, supposedly [[DifferentWorldDifferentMovies from a text]] called ''[[Literature/WitchesAbroad Watches Abroad]]''.
* NakedPeopleAreFunny: Rincewind initially tries to dress down for a visit to Georgian London, believing nakedness is the universal dress code. Ridicully won't have any of it.
* NeverLearnedToRead: Elves don't read. Elves get other people to read ''for them''.
* NiceJobBreakingItHero: The wizards foil the elves from enslaving mankind, but this means humans without any real ''human''-ness.
* NiceJobFixingItVillain: The Wizards nearly foil their plan in "The Globe" by teaching Shakespeare "The Hedgehog Song". But the Queen of Elves, under the assumption that the Wizards are ''trying'' to stop Shakespeare from writing ''Theatre/AMidsummerNightsDream'', using her powers to strip the song from William's mind.
* NoMoreForMe: When Rincewind trudges up out of the primordial ocean onto the primordial beach, the narration notes that many religions have been inspired by the [[SexySurfacingShot image of a person emerging from the sea]], but this particular vision would be unlikely to inspire anything except a desire to avoid strong drink in future.
** An emaciated ragged man with a straggly-ill-kept beard and a haunted expression staggering out of the sea fixated on completing a mission. [[Series/MontyPythonsFlyingCircus It]]'s possibly a ShoutOut? Or a {{Homage}}?
* NoNameGiven: Reaches its climax here, with the wizards even naming elements things like "Runium" and "Wranglium" after their titles rather than their actual (unknown) names.
* NoodleImplements: While preparing for Shakespeare to write ''Theatre/AMidsummerNightsDream'', the Wizards run into various problems that Ridcully solves via a set of noodle implements. Most of the time the reader can easily figure out what he is going to do with them (The sole exception being related to a folk remedy that is explained in one of the science chapters).
* NotQuiteTheRightThing: Nightingale's plays are sort of like Shakespeare's, but for a variety of reasons just not as good.
* NoTrueScotsman: Used by the non-fiction section in book 2, describing the scientist the wizards meet. The non-fiction section says he isn't a real scientist, on the basis of falling into despair after proving his precursor wrong - a ''true'' scientist would kill for a chance to prove something wrong.
* NuSpeling: The glimpse of humanity's future at the end of the first book includes such spellings as "alaam" for "alarm", "maetnans" for "maintenance", and "emerjansi" for "emergency".
* OneIPreparedEarlier: In the first book, Ponder explains his planet-making methods using Roundworld rules, before presenting another planet he made earlier. This one turns out to be Earth.
* PaperThinDisguise: The Librarian is able to disguise himself as a Spaniard via a large dress. Since the wizards are in Elizabethan London, it's enough. In Victorian London, Ridicully figures with the right hat and jacket he'd be able to become Prime Minister.
* ParodicTableOfTheElements: It's the standard table, except with extra space for narrativium and octium.
* PlanetOfSteves: The "edge people" created by the wizards interfering are all called Ugg. Or at least, this is the closest they can be bothered to get to naming themselves.
* ReadingTheStageDirectionsOutLoud: In ''Darwin's Watch'', Hex makes several dramatic announcements to the wizards, and says the words "pause for dramatic effect" before saying the last word. Ponder eventually tells him that he doesn't need to do that.
* RefugeInAudacity: In order to save Darwin, Rincewind has to be seen. In doing so, he dresses up in the most ridiculously over-the-top fashion, reasoning that Darwin won't tell anyone what he's seen, and that no-one will believe him if he does. Since history has never recorded of Darwin being saved by a wizzard dressed as a clown, it seems to work.
* {{Retcon}}: The first book uses 'splitting the thaum' as a magical equivalent of 'splitting the atom'. In previous books, thaums were just an arbitrary measurement of magic (and with the competing Prime system) rather than the smallest possible unit of magic. (This definition of the thaum first appeared in ''Literature/LordsAndLadies'', but buried in a footnote to an essay on the nature of magic. This is the first time it's actually been explored. Thaums also continue to be used as a measurement when one is needed. It's not even clear if it's the same thaum; it would be very UU to use the same word for two distinct concepts and just trust that everyone will know which one you mean.)
** This sub-series seems to suggest that not just the Discworld itself but the entire universe in which it resides runs on magical principles rather than the laws of physics, with stars described as tiny points of light and so on, whereas earlier books implied that normal stars and planets also existed alongside Great A'Tuin and a few other oddities like planets made from the corpses of giant dragons, with things like the TheoryOfNarrativeCausality and (barely) FunctionalMagic only existing inside the Disc's self-contained BackgroundMagicField.
*** Which seemingly gets retconned again in Book IV, which mentions they have indeed observed normal planets and stars passing by the Discworld. Blame quantum.
* {{Retgone}}: What would've happened if the experiment had gone wrong. It wouldn't have just blown up the Discworld, it would've destroyed reality entirely so that it never happened. Since Ponder was alive to turn the thing on, he reasoned it probably just happened to some other unfortunate sods in another timeline.
* RuleOfCool: The first book originally skipped over the thunder lizards when showing the development of life on Earth. A later edition went back and added a chapter because... well, ''dinosaurs''.
* RunningGag: In the second and third volumes, the Wizards find history has been meddled with and someone surnamed Nightingale has been inserted into a place someone else (William Shakespeare and Charles Darwin, respectively) should have been in.
* ScienceMarchesOn: Chapter 10 of Book Four illustrates the nature of science by devoting some space to the theories the first book favoured about the formation of the moon and the origins of life, and explaining why they're probably wrong after all. [[invoked]]
* SeriesContinuityError: Book 2's brief appearance of Granny Weatherwax portrays her as innumerate, when prior appearances have had it that Granny is a ''demon'' with numbers. It's literacy she's got no truck with.
* SeriousBusiness: On the Disc, the origins of the warning label "may contain nuts" came about because the Patrician takes food hygiene warning very seriously, and asked the wizards to help determine whether or not packing would contain nuts. He wasn't entirely satisfied with their answer that they couldn't conclusively prove that it did or did not.
* ShamuFu: In one timeline, Shakespeare is killed with a pike during a riot shortly after staging his first play. That is to say he was beaten to death by a fishmonger using his own wares, not impaled with a long medieval spear.
* ShoutOut:
** One of the rules Ponder deduces for how things work on Roundworld is "[[Literature/TheSecondComing Things fall apart, but centres hold]]."
** The enchanted VR suit Rincewind uses to explore prehistoric Earth, described as a bulky thing that looks like it was made out of some kind of bones, is not at all dissimilar to the "Space Jockey"'s pilot suit from ''Film/{{Alien}}''. Funnily enough, the book was written over a decade before ''Film/{{Prometheus}}'', which reveals those creatures also visited early Earth and influenced its development.
** The Dean's proposed mile-high limpet, as the only life form on Earth to get anything like immortality, is identical to Leviathan - the oldest living creature on Earth in the ''Literature/{{Illuminatus}}'' trilogy, with a point-for-point correspondence in the description.
** Rincewind's discussion about all the things you can make from [[TrademarkFavoriteFood potatoes]] with the Elf Queen in book 2 apes Bubba's similar discourse on shrimp with Film/ForrestGump.
** In book 3, the Dean re-enacts that scene from ''Film/DirtyHarry''. The Auditor he's against is smugly sure he's got no chocolate left... then Dean fills it full of nougat (and admits, actually, he ''wasn't'' sure he had any left).
** The narration in chapter 2 of book 4 mentions the unlikelihood of someone [[VideoGame/CommanderKeen building a spaceship out of old bean tins]].
* SistineSteal: The first book includes a scene where the Librarian (a wizard transformed into an orangutan) is magically searching for information about evolution and accidentally ends up in UsefulNotes/CharlesDarwin's study while he's in the middle of writing ''On the Origin of Species''. The resulting scene is not illustrated, but one can imagine what it would look like if it were.
-->"What manner of shade are you...?"\\
A hand reached out, tremulously. Feeling that something was expected of him, the Librarian reached out as well, and the tips of the fingers touched.
* SitcomArchnemesis: The Unseen University and those ''bastards'' at Braseneck University. One of the advantages of having a Very Big Thing is that it's better than Braseneck's.
* SkewedPriorities: Ridicully tells the Dean to stop playing on the squash court not because doing so (wizard squash being decidedly different from Roundworld squash, due to magic) is endangering everyone's life, but just because he feels wizards running around getting sweaty is unhygenic.
* SmarterThanYouLook: Ridicully's intelligence rears its head in book 1, when he notes, after Ponder supposedly turns the machine on, that he never would've done so in front of the wizards unless he was sure it actually ''worked''. In fact, the machine had been turned on earlier, at breakfast.
* SophisticatedAsHell: The chapter in the first book explaining the premise of the non-fiction segments explains that it could have been like ''The Physics of X-Files'', trying to explain the logic of the setting, but that this would've been "dumb".
* SpaceElevator: One appears in Book One. In the later books, the wizards' goal is the continued existence of a timeline that contains it.
* SpottingTheThread: In Book 3, Hex starts noticing the sheer amount of events going on that prevent Darwin from writing ''Origin of the Species'', and comes to the conclusion someone is doing so deliberately.
* SteppingOutForAQuickCupOfCoffee: When the wizards are wondering how to arrange things so that Roundworld's history gets back on track, Ponder suggests using L-Space to get books from alternate futures. The Librarian is enraged, as this would violate library rules, but Ridcully steps in to point out that ''not'' doing so would result in all the libraries on Roundworld being destroyed. The Librarian suddenly develops an impulse to go and find the books in question, leave them in a pile and go out of the room for a while, happening to cough loudly just before he returns, and nobody is to do anything naughty like reading the books while he's gone, okay?
* ThisIsReality: The Fairy Queen's gloat to the Wizard in book 2, basically. On Roundworld, [[DarkHorseSibling a king's third son]] is just [[SubvertedTrope a lazy prince]], and an old woman isn't a witch, just an inexpensive means of keeping the fire going a little longer. It's ''their'' world, not the Wizards'.
* TimeAbyss: The elves and their Queen invade Roundworld in the time of early hominids, and are still hanging around in Elizabethan times. And one of the regular elves is mentioned as having outlived ''several'' Queens and preyed upon many previous worlds' inhabitants, which suggests it's witnessed multiple sentient species' complete evolutionary history.
* TimeyWimeyBall: It's revealed in the fourth book that because Roundworld and Discworld are connected by L-Space, they've influenced each others' mythologies, meaning that when the wizards created Roundworld, they inadvertently altered their own history to create the Omnian doctrine of a spherical world.
* TryToFitThatOnABusinessCard: By the beginning of book 2, Rincewind has accumulated seven different titles (on the provision that he in no way act like this grants him any authority within the university whatsoever). By the beginning of book 3, this has grown to nineteen.
* VillainDecay: As of ''Darwin's Watch'', the [[CelestialBureaucracy Auditors]]' WeaksauceWeakness to chocolate has apparently worsened, to the extent that it now kills them even when they're not in human form. This is {{handwave}}d by Ponder stating that spending time in the material world causes them to develop crude physical senses, but that doesn't make much sense considering that prior to ''Literature/ThiefOfTime'' they didn't even know what chocolate ''was''. If the universe is so full of deadly threats to them[[labelnote:*]] it doesn't have to be chocolate specifically -- just anything that causes a strong enough physical sensation to overwhelm them[[/labelnote]], you'd expect them to have identified them all over the millennia and learned to avoid them.
* WelcomeToTheRealWorld
* WhatDidIDoLastNight: The wizards experience this in ''The Science of Discworld II'' after they spend the night drinking with Creator/WilliamShakespeare. Rincewind is the only one who can remember ''everything'' they did, and wishes he hadn't.
* TheWorldIsAlwaysDoomed: In the first book, the wizards become discouraged when Roundworld is repeatedly (As in, every several million years or so), hit by a large comet or asteroid.
* WretchedHive: Rincewind's opinion of 16th century London - like Ankh-Morpork, but ''worse''.
* YearInsideHourOutside: Early in the Project, millions of years pass in Roundworld for every Discworld day. Later, Hex takes control of time's passage within the artificial universe, and can subvert, avert, invert or play this trope straight at will.
* ZanyScheme: The wizards' interventions. Particularly the NoodleImplements-heavy one in volume 2, where they invoke various folk remedies to ensure William Shakespeare is born a boy.
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