Literature / Ringworld

Louis Wu: It looks like a star with a ring around it. What is it?
Chiron: It is a star with a ring around it. A ring of solid matter. An artifact.

An epic science fiction series by Larry Niven set on the original Big Dumb Object.

Imagine a giant ring, a million miles wide, with a radius of one Earth orbit and a circumference of some 600 million miles, orbiting around a star. The Ring is far enough out that the heat is comfortable for humans to live on. It spins to mimic gravity, and has walls a thousand miles high to keep the air from spilling off its sides. Such a ring would have an inhabitable surface area equal to almost three million planets the size of the Earth.

It is big. It is huge. Much of the work dealing with the Ringworld is about the difficulties of such a large world. The issues include how it was made, who could have built it, the various societies developed on it over time, and the problem of running it.

The main series contains the following novels:

• Ringworld
• The Ringworld Engineers
• The Ringworld Throne
• Ringworld's Children

Companion novels include:

• Fleet of Worlds
• Juggler of Worlds
• Destroyer of Worlds
• Betrayer of Worlds

Ties into Niven's Known Space series.

It has been adapted into the following games: Ringworld RPG, Ringworld: Revenge of the Patriarch, and Return to Ringworld.

Unrelated to Discworld, though it was a major influence on Terry Pratchett's earlier book Strata.

A Live-Action Adaptation of the first novel is currently in pre-production at Prime Video.

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Tropes encountered:

• Above the Influence: Nessus uses the tasp on Halrloprillalar in order to enslave her to Louis Wu's will through over-stimulus of her pleasure center. Louis is disgusted by this and refuses to take advantage of it. Instead, he helps her break the addiction.
• Absurdly Sharp Blade:
  • The variable sword, a piece of monomolecular wire held taut by a stasis field.
  • The Shadow Square Wire. A heap of it looks like smoke from a distance. It will slice apart any matter that touches it: trying to pick it up will cut off your fingers, and one character even runs into a trap made from it and gets his head cut off (fortunately he has a spare).
• After the End: The Ring once had a widespread civilization^note which only covered about twelve degrees of the Ring, but given the size of the Ring itself it dwarfs civilizations that cover multiple star systems, but it fell — literally. Only a few remnants of the City Builders are left, now mostly reduced to living in isolated settlements within the crumbing ruins of their once-great cities, within a land mostly gone to wilderness and barbarism.
• Alcohol Is Gasoline: The Machine People distill a form of ethanol used both as fuel and as drink.
• Alien Sky: The Ringworld sky is dominated by the Ring, which appears like an immense arch over the heavens, and "night" is produced by the Shadow Squares that create very sharp, alternating bands of light and darkness without any twilight period — the day-night cycles alternates precisely between high noonday light and deep star-studded darkness.
• Aliens Never Invented the Wheel:
  • Natives sometimes find it tricky to draw the line between intelligent and non-intelligent hominids, as different species' earliest technological advancements don't always correspond. For example, some aquatic species use flaked stone tools but have never discovered fire.
  • The Pak never invented perfume. This has catastrophic consequences for their species, as being able to apply the odor of one's offspring to non-relatives might have averted millions of years of genocidal warfare among bloodlines.
• Ancient Conspiracy: It's revealed in the first novel that the Puppeteers secretly interfered in the Man-Kzin wars to try and breed docile Kzinti and also secretly lobbied for the Birthright Lottery to breed someone like Teela Brown. In the second novel, we also learn that the Puppeteers secretly engineered the Ringworld's superconductor plague so that they could investigate the Ringworld safely and so that they could arrive in the nick of time and save everything, making a lot of money and getting a lot of power in the process. Then politics happened between sowing the plague and fixing it, and the fixing never happened.
• Aroused by Their Voice When Luis Wu meets Nessus for the first time, he notes that the Puppeteer's voice sounds like a synthesis of every attractive woman he can think of, and is very frustrated that this comes from an alien without even a passing resemblance to a homind body.
  Had Louis visualized a woman to go with that voice, she would have been Cleopatra, Helen of Troy, Marilyn Monroe, and Lorelei Huntz rolled into one. "Tanj!" The curse seemed more than usually appropriate. There Ain't No Justice! That such a voice should belong to a two-headed alien of indeterminate sex!
• Artificial Gravity: The Ringworld generates this using the centrifugal effect.
• Artistic License – Geography: Louis Wu teleports from city to city on his 200th birthday, to stay ahead of midnight and stretch the day out... but the first printing of Ringworld has him accomplish that by travelling from west to east.
• Artistic License – Paleontology: The Paks were Homo habilis (or Australopithecus habilis depending on how the phylogenetics turn out) and stated to be the common ancestor of not only humanity and all the Ringworld hominids, but Earth's other great apes such as chimpanzees and gorilla. However, humanity's ancestors diverged from chimps' several million years and at least one genus before H. habilis.
• Attack Pattern Alpha: In The Ringworld Throne, Luis Wu teaches Chmee's son Acolyte the value of predetermined actions, and in training until performing said actions are second nature. He compares it to an astronaut being trained so that the first thing he does in an emergency situation is put on his pressure suit without actually having to think about doing it, and then asks if wtsai (the Kzinti knife-fighting martial art in which Acolyte has been trained) has a "a default maneuver; a move that is used when you are surprised or if you aren't really sure which move to use." Turns out there is one: the disembowel.
• Author Appeal: Rishathra, which is cross-species mating used for the purposes of diplomacy on the Ring. Niven reportedly wore a shirt to conventions that says "I have sex outside my species"^note He wrote that if wearing a badge with the same slogan, you really have to remember to take it off outside SF conventions, or people draw funny conclusions.
• Badass Boast: "It was I who, on a world which circles Beta Lyrae, kicked a kzin called Chuft-Captain in the belly with my hind hoof, breaking three struts of his endoskeletal structure." — Nessus, making a Continuity Nod to the Known Space short story "The Soft Weapon".
• Beautiful Tears: Teela is described as being "one of those rare, lucky women whom crying does not make ugly".
• Big Dumb Object: The Ringworld itself is an ancient and mysterious super tech that dwarfs anything else in the galaxy. Though its population numbers in the trillions, the empty areas are so large that it feels practically abandoned.
  • The feeling is entirely justified. The human characters are used to planets with population densities a thousand times that of the Ringworld, and even the Kzinti character is used to population densities of his own species ten to a hundred times greater, and has spent the last few years on Human-occupied worlds.
  • A comment repeated is that the Ringworld isn't so big as to be incomprehensible — it's just barely small enough that the mind can understand how mind-bogglingly big it actually is.
• Bittersweet Ending: In The Ringworld Engineers, the protagonist and his party kill 1.5 trillion people, a couple hundred times as much as the Earth's entire population, and they're marooned on an alien world far from home. On the other hand, they save 28.5 trillion people, several thousand times the Earth's present populations.
• Bizarre Sexual Dimorphism:
  • Kzinti females are non-sapient, although it's all but stated that this is due to deliberate genetic engineering by the Kzinti males so long ago that they themselves have forgotten about it. This is supported by the fact that the Kzinti females on the Map of Kzin, descendants of Kzinti abducted in prehistoric times, are fully sapient beings.
  • It's suggested in the first book that puppeteer females must mate with two males, one of each of the two "male types" the puppeteers have, in order to conceive. In the second, the Hindmost (who is mated to Nessus) explains Puppeteer reproduction in more detail. The "female" Puppeteer is actually a different species, which acts as a host for the embryo formed by the gametes placed into it by the Puppeteers, whose two "male types" are their actual "male" and "female" genders. The organs used to deposit gametes are described as being "most similar". They're explicitly compared is to ichneumonoid wasps. Louis then understands why Nessus didn't want to talk about it.
• Born Lucky: Teela Brown, to the extent of being an in-universe Black Hole Sue due to her luck twisting all events that she's in to make them ultimately about benefiting her. This is also deconstructed, since a lifetime of not experiencing any harm or difficulty worth the name has left her, in many ways, as a child in an adult's body.
  • It's brought up at one point she might not have been born all that lucky at all, she's just a statistical anomaly that just looked that way for the benefit of people who were — or who were just born way more lucky (that or their kids' would turn out to be really lucky that a lucky-enough person wound up going to the Ring when she did). (Trying to follow cause and effect in a universe with people whose mere existence is supposed to cause the entire universe to automatically conspire in their favor is a serious Mind Screw.)
  • Louis Wu discusses this at one stage, making the obvious suggestion that it may simply not have worked at all. Later on, it turns into Be Careful What You Wish For as Teela morphs into a Protector, at which point it becomes obvious that what actually constitutes "luck" is so subjective as to be meaningless.
  • There's a massive argument for Unluckily Lucky. After all, what Teela needs at any point might not necessarily be what she wants. It's unlikely to be what those around her want (or need), either. And then you've got her kids to think about. Or her lottery-cousins' kids. And all their kids. Protectors are all about the bloodline, after all. Even the supposedly "lucky" ones might have luckier relatives who might "need" them where they wind up being when it's lucky for the entire group down the line, regardless of what emotional wringers it puts the individual (and those around them) through. Because warped statistics mean somebody suitable enough is going to get tapped for it. Ouch?
• Brown Note: The descriptions of the vast dimensions of the Ringworld have given people nausea from misplaced vertigo (1000 mile high mountains no thank you).
• Captain Oblivious: Teela Brown. Due to her incredibly lucky nature, she's unaware of physical or emotional pain or negative consequences of her actions, to the point that she's described as having a gangling, awkward way of walking because she's never had to learn to avoid obstacles. After breaking up with him, Louis surmises that her luck eventually brought her to the Ringworld so she could be taught a number of life lessons regarding danger and that her actions have consequences for others, and among other things she'll probably be able to live forever so long as she takes up residence there..
• Centrifugal Gravity: The Ringworld is far too large for artificial gravity to be an efficient option for it. As such, it rotates around its star to use centrifugal force to keep everyone's feet on the ground.
• Chestburster: Louis suspects that puppeteers reproduce this way, although there is no definitive confirmation about whether he's right. (Fleet of Worlds only confirms that gestation is always fatal to the "mother"/host.)
• Combinatorial Explosion: The game has the character carrying around a spacesuit for most of the game. An area of poison gas blocks your progress until you figure out how to remove it. Putting on the airtight space suit is not an option. Its only use is as a diving suit near the end.
• Consummate Liar: Almost all of the information that Halrloprillalar provided in Ringworld turned out to be untrue thanks to retconning.
• Continuous Decompression: The Ringworld has a hole in it with air continuously leaking out into space. It creates a huge storm that looks like an eye from the side. However, given how incredibly huge the Ringworld is, it would take a long time for all air to leak out. According to Niven, the erosion caused by the resulting superstorms would end all life on the ring long before that, though.
• Converging-Stream Weapon: The upgraded Slaver Disintegrator. Normal Disintegrators produce a beam that suppresses the charge of the electron on solid material it hits, causing it to have a uniform positive charge and, due to the resulting unopposed repulsive forces between nuclei, violently tear itself apart into atomic dust. The upgraded version also fires a beam that suppresses the charge of the proton and lands a short distance away from the first. Besides more disintegration, this also creates a massive electromagnetic implosion between the two charged areas.
• Cool Ship: Anything that reaches the Ringworld from Known Space in a reasonable amount of time qualifies. Eventually the Ringworld itself qualifies as the largest starship ever.
• Cowardly Sidekick: Nessus, through and through. It's a known trait of his people, to the point that puppeteer society considers him insane for willing to risk his life to starship travel. Other known space stories emphasize that puppeteer society is right: space traveling puppeteers are mentally ill, and they will often have comorbid disorders.
• Dangerous Phlebotinum Interaction: Known Space has the life-extension drug boosterspice. The inhabitants of the Ringworld have their own life-extension drug, but you can't take both: boosterspice is poisonous to someone who's used the Ringworld drug.
• Dead Guy on Display: In The Ringworld Throne, it's mentioned that the body of one Harvey Mossbauer is kept on display in the House of Patriarch's Pride, the royal museum of the Kzinti. In response to having his family killed and eaten during one of the Man-Kzin wars, Mossbauer had landed on the Kzinti homeworld, fought his way into the harem of the Patriarch, and detonated a bomb there. After killing him, the Kzinti stuffed him and put him on display as an "honored foe".
• Decade Dissonance: This justified by the sheer size of the Ring. There simply hasn't been enough time since the collapse of the last advanced Ringworld society for technology (like gunpowder) to spread very far, which means that the Ringworld's cultures are a patchwork of tribal societies, small agricultural states, emergent industrial cultures, and fragmentary remnants of the City Builders' ancient empire.
• Do You Want to Copulate?: Rishathra (sex between different species of intelligent hominids) routinely occurs to seal the deal on trade or peace agreements, or just to get one's rocks off without having to worry about pregnancy.
• Dropped a Bridge on Him: Halrloprillalar dies between the first and second books, due to the interaction of incompatible drugs.
• Electric Instant Gratification: The tasp, which stimulates the pleasure center of the brain from a distance, and the droud, a surgically implanted device used by current addicts to generate the same effect by means of a wire slotted directly into the brain.
• Emotion Bomb: Vampires produce a pheromone that can override any non-sex-related thoughts in the victim while the vampire feeds.
• Exotic Equipment: The Ringworld is home to thousands of Pak-descended hominid species, nearly all of which are sexually compatible (albeit not fertile) except when their overall body sizes are too extreme and/or one of the prospective partners has to mate underwater. A very early part of negotiations with a new species is finding out if this is possible ("How long can you hold your breath?")... some can't for physical reasons, and at least one species is physically compatible but can't for psychological reasons. Exotic equipment does oblige Chmeee, a non-hominid alien who claims to have "no external genitalia", to sit out the cross-species games; at one point, he exposes himself to a native to show why he can't participate.
• Explosive Breeder: City Builders are extremely fertile, such that every act of mating within their species automatically results in offspring. Females also go into heat periodically, making abstinence all but impossible for them. Their main way of avoiding overpopulation is to mate with other sorts of hominid, with whom they're not mutually fertile.
• Exposed Extraterrestrials: Unlike humans or the Ringworld's other species, the Grass Giants have no cultural sense of body shame and wear no clothing or adornments.
• Faceless Eye: Eye storms, caused when a meteor puncture in the Ring bed drops air pressure sharply; Coriolis effects shape the surrounding cyclone into a miles-high lidded eye shape. The first time the protagonists see one, Speaker to Animals has a minor crisis episode due to his odd religious upbringing.
• Famous, Famous, Fictional:
  • Louis' opinion of Nessus' voice — "Had Louis visualized a woman to go with that voice, she would have been Cleopatra, Helen of Troy, Marilyn Monroe and Lorelei Huntz rolled into one."
  • He does it again in Ringworld's Children, describing the state of the Fringe War — "It'll be like the Wars of the Roses, or The Vietnam War, or Avenge Mecca: it could last forever. Nobody knows how to turn off a war."
• Faster-Than-Light Travel: The characters make use of two different FTL drives to reach and return from the Ringworld. A one-off prototype that makes the trip in days and the standard commercially available slower speed that takes over a year to get there from Known Space.
• Fell Asleep Driving: In the first book, while the group is hover-cycling over a plain larger than the Earth, Teela Brown gets a bad case of "highway hypnosis" and crashes. Due to her ridiculous quasi-psionic luck she's fine, but the others nearly get killed trying to rescue her.
• First Injury Reaction: In the first book, Teela has never experienced serious injury or pain thanks to her inborn natural luck. When their spaceship crashes, she blithely attempts to climb out of the burning hot crater without protection, and is shocked when it burns her feet.
• Flat World: The landscape of the Ringworld is a very long, very thin flat world, as it only has one side and has edges walled off with hundred-thousand-mile high walls. Its diameter is so great that any local deviation from a flat plane is negligible. It also has no true horizon — distant objects just get more vague and indistinct until the far side of the ring starts curving back up into the sky.
• Floating Continent: Ranging in size from buildings to cities, these were very common on the Ringworld before the Fall of the Cities. It's mentioned most advanced species could build these just as easily as the City Builders could, but choose not to for a number of reasons (the humans and Puppeteers find them too unsafe, and the Kzinti dislike heights).
• Food Pills: The hoverbikes provided to the protagonists, when loaded up with raw organic matter, provide bars of delicious nutrients that are tailored to the tastes of various species using them.
• Foreign Queasine: The City Builders are disgusted by Louis Wu's love of cheese, and Halrloprillalar also detests coffee.
• Formerly Sapient Species: When the Pak protectors built the Ringworld, they introduced no animal life to it beyond their own kind, some food animals and microfauna. As such, when the Pak empire collapsed and the Pak breeders (Homo habilis) were left on their own, the breeders radiated to fill the various empty niches in the massive world they found themselves in. Many of their descendants redeveloped sapience, but others — such as the predatory vampires — remain little more than cunning animals.
• Free-Love Future: In a sense. Inter-species sex, called rishathra, is the standard way to seal deals between parties of different species.
• Fully Absorbed Finale: Louis' storyline in Ringworld's Children is concluded in Fate of Worlds, the fifth and final installment of the Fleet of Worlds series co-written with Edward M. Lerner.
• Gambit Pileup: The third and fourth books become this when dozens of protectors start plotting against each other.
• God Guise: The strategy that the characters call the "God Gambit", where they pretend to be gods among Ringworld natives.
  • In the first book, the group use their advanced technology to make the primitive inhabitants think that they're deities. Unfortunately, it backfires because Louis can't keep a straight face.
  • Played straight with considerably more success in the Ringworld Engineers''. This time, they keep the "god" off camera — Chmeee, the ferocious carnivorous eight-foot-tall Kzin, presents himself as the god's servant, reacting with obvious awe and fear to The Voice from their transport ship. It almost falls through when the leader of the giants claims that Rishathra is a requirement for any agreement (even an agreement with a god). Since Chmeee is a pseudo-feline alien with no external genitalia, he can't have sex with a hominid. So Louis comes up with an alternative. He "creates" a mute human servant for himself, calling him Wu (of course, it's just Louis himself staying mute so as to not give away his voice), who ends up having Rishathra with one of the leader's wives to seal the deal.
• Handy Mouth: In the series, the Puppeteers use their two mouths as hands. The mouths are perfectly suited for this, even possessing little fingerlike projections.
• His Name Really Is "Barkeep": Speaker-to-Animals is known by his profession (as are all Kzinti) until he has earned the right to choose his own name. While it isn't specifically stated, Acolyte appears to have the same issue.
• Hot Librarian: Harkabeeparolyn worked as a librarian in her floating city and is attractive for a City Builder, if you're into rishathra.
• I Cannot Self-Terminate: In The Ringworld Engineers, Teela Brown has become a Protector whose descendant-protecting instincts are paradoxically making her try to stop the main characters from saving the Ringworld. She is, however, just rational enough to provoke the main characters into killing her so that they can get on with the job. It helps slightly that Louis is literally the only creature on Ringworld who is technically the same species as she is, so her protective instincts are slightly stronger towards him then they are towards the Homo but not sapiens Ringworld natives. She doesn't feel any instinctive compunctions to keep the alien Chmeee alive, though. Luckily, he's a half-ton of obligate carnivore from a Proud Warrior Race, and can look after himself. She still half-kills him while desperately trying not to fight as effectively as she can, though.
• Interspecies Romance: "Rishathra" is sex between different species used for diplomatic purposes or when meeting new tribes. It's also apparently a form of birth control for those species that get pregnant every time they mate amongst their own, as most species aren't interfertile.
• Kill Sat: The Ring is defended by a magnetically controlled x-ray laser made by the forced-fluorescing of sunspots. The beam of this weapon is the width of Earth's moon.
• Laser Cutter: Louis uses a flashlight laser in a similar matter to a bladed weapon, albeit one that has a very long reach and cuts deeper when slashing more slowly, a sort of realistic version of a laser sword.
• Locking MacGyver in the Store Cupboard: In Ringworld's Children, Tunesmith (a super-intelligent Night Person protector) is smart enough to lock Luis Wu out of the stepping disk system in order to keep Luis from escaping, but somehow didn't think it important to lock Luis out of the autokitchen menu. So naturally Luis orders sushi from the autokitchen, a meal that is dispensed alongside a pair of hardwood chopsticks... which Luis uses to hack his way into the stepping disk system and escape.
• Longevity Treatment: Boosterspice is a synthetic drug to extend the user's lifespan by several times. Louis is a man of two hundred years, but is as hale as a man a tenth of that. There is an equivalent to boosterspice available on the the Ringworld, each does increasing the user's lifespan by fifty years.
• Losing Your Head: In the first book, Nessus loses a head to the shadow square wite. Luckily for him, his species has two heads, and neither of them is where Puppeteers keep their brain. It's at most an inconvenience until he can get a new head attached.
• Loss of Identity: Nessus gains leverage over Chmeee by dosing him with (hitherto unknown) Kzinti boosterspice. Because he is now younger and scar-free, he would lose his rather comfortable identity in Kzinti society unless he is provided with evidence to support his story. Chmeee also considers his scars to be part of his personal identity as a warrior, and the loss of them to be almost like losing his memories of the fights where he got them.
• Lost Technology:
  • The inhabitants of the Ringworld have lost the technology to build, repair, or understand it (mostly; the Protector builders left a couple of caches behind, and ensured that anyone who finds them will be smart enough to figure out how to use them).
  • The City Builders were a below the tech level required to construct the place (or understand it, demonstrated by the fact that they dismantled the stabilization system), which collapsed when the Puppeteers destroyed their superconductors, but which left bits and pieces of equipment based on different technology lying around, some of which still work. Modern Ring societies are for the most simple nomadic or agricultural affairs living in the shadow of their predecessors' bygone technological empire, which they view as a time of gods.
• Love Is in the Air: Vampires have super-pheromones that induce a very distracting mating frenzy in their victims. "Essence of Vamp" is a popular perfume among City Builders.
• Metal-Poor Planet: As an artificial world, there are no mineral ores on the Ringworld: if you dig into a mountain, you'll hit the scrith underlying the sculpted landscape after a few hundred meters. As a result, if civilization on the ring collapses it will remain stuck at the stone age. Consequently, Larry Niven is constantly talking about all the ways that the Ringworld is reacquiring knowledge. The ghouls have an extensive communication network and advanced knowledge, City Builders have huge libraries, returning ships have brought back advanced knowledge, and Protectors with their genius intellects are constantly turning up all over the Ring. Add to that a large number of Known Space ships marooned all over the Ringworld with vast information storage libraries and you're looking at a dawning technological renaissance.
• Mile-Long Ship: The Kzinti of the Map of Kzin live in a united society ruled from the Behemoth, a 1.6-kilometer-long seagoing vessel driven by hydrogen power.
• Neglectful Precursors: The Pak built the Ringworld and seeded it with Pak breeders, Homo habilis. It's a pity the Pak are so bad at building societies.
• Nobody Ever Complained Before: Sex is often used as an interspecies social/political lubricant — since the species all evolved from a common ancestor, so they all have the same basic sex organs, but they've diverged enough that they can't get each other pregnant. When Louis Wu turns down offers, he is usually greeted with confusion or amusement.
• No Sidepaths, No Exploration, No Freedom: In Ringworld and Ringworld II: Revenge of the Patriach, you never really get to explore the Ringworld. Your ship essentially takes you directly to the location of your next mission or subquest, so you mostly end up exploring a series of primitive villages and caves.
• Not Drawn to Scale: Many of the artists in various countries who paint cover art for the Ringworld novels have a hard time grasping the proportions of it. One of the few exceptions is Rick Sternbach's cover, pictured above. A to-scale drawing of the Ringworld isn't very dramatic. As Niven himself put it in The Ringworld Engineers: "Picture fifty feet of baby-blue Christmas ribbon one inch wide. String it in a circle, on edge on the floor, and put a candle in the middle. Now expand the scale: The Ringworld was a ribbon of unreasonably strong material, a million miles wide and six hundred million miles long, strung in a circle ninety-five million miles in radius with a sun at the center."
• Odd Organ Up Top: Zigzagged by Pierson's Puppeteers, which have their brains in their thoracic cavities. Their two heads, resembling hands with Extra Digits, play no role in thinking, instead being used mainly for seeing, eating and manipulating objects.
• Off to See the Wizard: After finishing the first book, Larry Niven realized that its plot and characters mirrored those of The Wonderful Wizard of Oz. (Louis Wu is Dorothy, Nessus is the Cowardly Lion, Speaker-To-Animals is the Scarecrow, Teela Brown is the Tin Man, and Halrloprillalar is the Wizard.)
• Oh, My Gods!: Louis Wu swears by "Cthulhu and Allah!"
• Older Than They Look: Louis Wu, Chmeee, and pretty much anyone else who has taken boosterspice or used Carlos Wu's nanotech autodoc.
• Once Done, Never Forgotten: Because Red Herders are culturally monogamous, much of the conflict in the "Fearless Vampire Slayers" storyline in The Ringworld Throne comes from Tegger and Warvia fearing that they'd get a reputation for promiscuity after all the rishathra they had while under the influence of vampire scent.
• Orgasmatron: A device called a "tasp" can remotely stimulate the pleasure centers of a being's brain. It is very addictive and use of it on someone without their consent is highly illegal. While it does not explicitly cause orgasm, Nessus (a manipulative alien) uses it to make Prill (a humanoid whose help the protagonists need) addicted to sex with Louis Wu. It is also compared to sex when the narrative muses that "all women have a tasp" that they use to manipulate men to do their bidding.
• Orphaned Etymology In The Ringworld Throne, a native of the Ring refers to how the irritable chieftain of the Grass Giants might "go off like a volcano" if he finds out about something, which is puzzling because Ringworld has no volcanic activity.
• Our Better Is Different: The Puppeteers value survival to the point of cowardice, so their leaders are "those who lead from behind" and the highest ranking one is called "the Hindmost". This has a hidden subtlety. As herd animals, the Puppeteers don't charge enemies the way territorial hominids do; they run away. So the hindmost member of a puppeteer herd is actually the rear guard, the most exposed and combative of the bunch. It's unclear if the title of Hindmost is actually meant to be read this way, or is a Cultural Translation into human terms.
• Our Ghouls Are Creepier: They are a carrion-eating species of Ringworld hominid who are the Ring's garbage collectors, long-range communicators, information brokers and undertakers. Yes, they eat the dead. The other races usually don't object — that's their job — but when they do this has always resulted in aggressive negotiations by the ghouls, followed by extermination by the ghouls if said race doesn't get the point. No one knows how advanced the ghouls are and no one wants to find out.
• Our Giants Are Bigger: The Grass Giants are a very large, herbivorous race of Ringworld hominids evolved to fill the ecological role large grazers normally hold. Although large, they're large in a humanoid scale — typically they're around two to three meters tall, with larger males reaching the full three, and can engage in rishathra (sex with other hominids outside their species) without much trouble.
• Our Vampires Are Different: They are non-sapient, at least until transformation into a Protector. They also attract their prey with pheromones and are technically a number of different hominid species that evolved convergently into the same niche.
• Overly Long Name: City Builders, and races influenced by their culture like the Machine People, have names five to six syllables long.
• Percussive Maintenance: Teela Brown activates her sky-cycle's emergency booster at a key moment by fainting and smashing her face on the control panel, thus saving her life. The emergency booster required several controls to be hit in a specific order, at least one of which was recessed and thus much harder to hit accidentally. The other characters take this as proof that she was literally Born Lucky.
• Perpetual Storm: Permanet hurricane-like "eye storms" form in places where asteroids have punctured the Ringworld and the air is draining out.
• Pheromones: "Vampires" secrete pheromones which are "close enough" to affect all other Pak-descendants (it's implied there are some hallucinogenic properties as well). The pheromone-fueled orgy that follows serves as a distraction to allow the vampires to feed.
• Plague of Good Fortune: Teela been selectively bred for luck. Unfortunately, she hasn't been bred to bring luck to those around her. Her expedition crashes and is nearly stranded because she, in particular, would be happier living there; that the others would all greatly like to go home isn't a factor in this equation. The other characters spend the sequels carefully staying thousands of miles away from her.
• Planetary Relocation: The Puppeteer Fleet of Worlds is a Klemperer rosette of five planets set to orbit in a pentagonal pattern around a common point by the Puppeteers.
• Prequel: The novels in the Fleet of Worlds series, co-written with Edward M. Lerner, are marketed on their front covers as prequels to Ringworld.
• Proud Warrior Race Guy: Like all Kzinti, Speaker-to-Animals (later Chmeee) and his son, Acolyte devote their lives to honorable combat.
• Put on a Bus: In Ringworld's Children, the Hindmost only briefly mentions that Harkabeeparolyn and Kawaresksenjajok were returned to their hometown floating city, and they otherwise don't appear in the book at all. Surprisingly, Niven gets Harkabeeparolyn's name wrong and calls her Fortaralisplyar, who was a different male character from the same floating city in The Ringworld Engineers. This seems to indicate that Niven doesn't hold Engineers in very high regard.
• Razor Floss: Several materials are invisibly thin filaments that can cut through almost anything, such as shadow square wire, Sinclair molecular chain and variable swords.
• Really 700 Years Old:
  • Louis Wu is almost two hundred and fifty years old by the end of the series but looks around twenty. It's implied Hindmost is (like most Puppeteers) several centuries older. And of course, protectors can live for thousands of years.
  • The last novel has a character who's the last surviving true Pak protector on the Ringworld. She's several million years old.
• Retcon: A bunch.
  • At the time Niven wrote Ringworld, he hadn't decided to Canon Weld his stories of the Belters and near-future space exploration, including Protector, into the same universe with the far-future stories of Beowulf Shaeffer and Louis Wu. This is why Nessus says "there is evidence enough that your species evolved on Earth," even though later novels show he would have known who the Pak were. It wasn't until after Niven established the future history of Known Space that he realized Pak protectors were the most likely builders of the Ringworld. In some author's notes he's said that he deliberately let Louis come to the wrong conclusion to simplify the first book.
  • Louis doesn't seem to know that the galactic core explosion was discovered by Beowulf Shaeffer. Later stories revealed that Shaeffer was his adopted father, and so must carefully note that Shaeffer kept his adventurous life a secret. Which is quite odd, as Teela reads about Beowulf's trip to the galactic core in Louis's library in his mansion. Apparently, Louis never bothered to check into the publicly available materials on his fathers. It's usually at this point that the Larry Niven discussion group starts mumbling about one or more lost generations between Beowulf and Louis. Yes, there are holes and no, you shouldn't hold your breath waiting for it to be patched up.
  • The inspiration for many of the sequels was to provide explanations for some of the technical problems invoked that other people found with the original design.
  • The native bird-hunters encountered in the first book didn't understand what sickness is, apparently under Niven's assumption that the Ringworld's builders wouldn't have brought diseases into their artificial habitat. By the third novel, someone must've pointed out to him that new diseases would evolve from benign soil bacteria that would've been necessary for its ecosystem; the existence of plagues on the Ringworld is acknowledged when one of the Night People describes how they'd directed the necessary cremation of victims.
• Ring World Planet: The trope maker for the "circular slice of a Dyson shell" variant. The Ring was created, conceptually, as a way to get the benefits of a shell-type Dyson sphere while scaling down the physical impossibility of the thing. It's made of Unobtainium called scrith, since no real material is strong enough to hold together under the immense centrifugal forces of its rotation, and is so massive that its geographical features include 1:1-scale maps of several planets (including Earth). These maps are significantly less than 1% of the ring's surface area. Day and night are created by massive solar panels in spinning in orbit between the sun and the ringworld. Bussard ramjets on the rim of the ringworld keep it centered, since by itself it would eventually fall into its sun. The whole thing is reasonably Ragnarok Proof, which is good, as it's also quite Ragnarok-prone: once high-technology civilization there collapses, the absence of available metals means that it can never arise again without outside interference.
• Rubber-Forehead Aliens: With the exception of the garden maps and food animals, any being with two arms and two legs is some sort of strange hominid species. Justified, since they all evolved from the same common ancestor as human beings from Earth.
• Schizo Tech: Ringworld, constructed as a kind of giant garden for children, is very low in metal elements. Technology hits a limit as there are no useful minerals available to be mined. There are just enough of the Pak's materials around for some civilizations to arise from time to time.
• School of Seduction: Halrloprillalar Hotrufan was a highly trained ship's prostitute/diplomat aboard a relativistic City Builder ship. Thanks to longevity treatments, she has also had thousands of years of sexual experience to sharpen her skills. A few touches are enough to get any human (or homind, as the case may be) male full of lust. Her position was important on a ship of mostly males on long sublight voyages (especially since there are no sexual taboos among City Builders).
• Shown Their Work: Niven is famous for working out the problems in his ideas. The problems and questions asked in the first novel lead to a sequel which had still more problems leading to more sequels...
• Spoiler Opening: Donato Giancola's cover painting for The Ringworld Engineers depicts a Protector, which spoils a major plot point of the book.
• Starfish Aliens: Nessus is a Pierson's Puppeteer, a creature with three legs, two heads, and its brain in the middle of its body. Nessus is noted to have his heads look at one another, his equivalent of a laugh. The Ring also has some transplanted Jinxian Bandersnatchi, sentient slugs the size of a freight train.
• Star Scraper: The party pays a brief visit to the homeworld of the alien Puppeteers. It is mentioned that "on Earth few buildings were more than a mile high, here none were shorter."
• Subspace Ansible: Faster-than-light communications technology does exist but it can't be used in a gravity well, so communicating across the Ringworld involves a lightspeed delay given it's just over sixteen light-minutes in diameter.
• Suspiciously Specific Denial: In the first book, Nessus takes pains to explain that his ship carries no weapons whatsoever, only tools. He then takes equal pains to explain the safety precautions that must be taken when using each of the tools, which could be incredibly lethal if used improperly. This prompts Luis to nickname the ship the "Lying Bastard".
• Tagalong Kid: In Engineers, Kawaresksenjajok is a City Builder child who accidentally stumbles into Hot Needle of Inquiry simply because the Hindmost forget to turn a stepping disc off after Louis used it.
• Time Abyss: In Ringworld's Children, the Protector Proserpina is around a million years old.
• Tools of Sapience One of the countless hominids is a borderline-sapient species which, while unable to use fire in its aquatic habitat, does use flaked stone tools.
• Tragic Monster: Teela, after becoming a protector in The Ringworld Engineers and deliberately forcing Louis to kill her.
• Transplanted Aliens: The Pak constructed replicas of other inhabited planets in Known Space and populated them with species from those planets, including the last Martians, Jinxian Bandersnatchi, and pre-genetic engineering Kzin whose females are still sapient.
• Transplanted Humans: Pak protectors are a form of Homo habilis who built the Ringworld as a safe place for their breeders to survive the core explosion. They did not place any animal, not even an insect, which would harm a humanoid. That left many ecological niches empty, and after three million years the humanoids have evolved to fill the roles. It's later revealed that other sapient alien species were later transplanted onto the Ring, including the Martians (extinct on their homeworld as of Protector) and primitive Kzin whose females are still sapient.
• Turtle Island: In the second book, it's mentioned that alien creatures large enough to have extensive vegetation growing on their backs live in the Great Oval Ocean.
• Unobtainium:
  • The centrifugal force of the Ring is so great, any physically possible material would be torn apart under the stress. Niven posits scrith, a metal with tensile strength on the order of the force that holds atomic nuclei together.
  • The novel also has a room temperature superconductor that also superconducts heat, both of which become important plot points.
  • The General Products Hull is transparent to visible light and only visible light, and absolutely impervious to any kind of harm except outright disintegration by antimatter.
• Utility Weapon: The starship which the Puppeteers outfit for the mission has nothing that could be called a weapon per se... but is so chock-full of tools that can be fiddled with to make them into weapons, like flashlights than can act as deadly lasers with enough focusing, that Louis Wu christens it 'Lying Bastard' in recognition of its deceptive design.
• The Vamp: Halrloprillalar, a highly trained ship's whore.
• Wacky Wayside Tribe: A number of Ringworlder communities encountered by the characters, like the Hairy Ones and the Grass Giants, serve to add flavor to the setting but don't have much bearing on the plot.
• Weak, but Skilled: This is generally Louis' shtick throughout the series until he eats Tree of Life. (Even then, he was still weaker than the other protectors he was fighting against because of his improperly healed broken leg.)
• Weather-Control Machine: The explorers create a living weather control machine by provoking some laser-firing plants to direct their beams at a shallow sea. This causes a huge cloud of steam to rise and sets off a localized rainstorm that continues indefinitely.
• Winds of Destiny, Change!: The Puppeteers have been breeding humankind for pure dumb luck. When Nessus attempts to recruit one of the more lucky members of the species in order to improve the odds of their mission, all of the candidates just happen to be on vacation or are having communication glitches, or are simply impossible to locate. Only one of these people is found and, unfortunately, her luck is more centered around her living a full life rather than being centered around her remaining comfortable and content, ultimately leading to the events of the book.
• Working for a Body Upgrade: In the second book, the Hindmost recruits Chmeee (formerly Speaker-to-Animals) for the second expedition by offering him the technology to perform Longevity Treatments on kzinti. The twist is, the Hindmost demonstrated the treatment on Chmeee, who now no longer looks like himself and must have the technology in order to prove his identity to the kzinti government and keep his property and name.
• The World Is Just Awesome: In Engineers, Luis Wu and Chmee land on the Ringworld's wall. The sight of the Ringworld stretching below him, displaying a land area orders of magnitude greater than the surface of the Earth, momentarily takes Wu's breath away.
• Zeerust: The Ringworld Engineers (1979) has computers that use magnetic tapes. Built by a race that make floating cities, interstellar ramscoops, longevity drugs, etc. Later novels in the series retcon the technology, stating that the longevity drug was almost certainly the result of a Protector needing money for a project, and implying that a lot of the other technology might have been passed along by Protectors for similar reasons.
• Zero-G Spot: Louis Wu and Teela normally sleep and have sex in weightless sleeping pods, except when using positions and techniques that require gravity.

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