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. 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.

Ties into Niven's Known Space series.

Unrelated to Discworld.

Tropes encountered:

 * Absurdly Sharp Blade: The variable sword, a piece of monomolecular wire held taut by a stasis field.
 * Also 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
 * After the End: The Ring once had a widespread civilization, but it fell-- literally.
 * "Widespread" compared to Terran standards. It never actually covered more than about a twelve degree arc of the Ring.
 * Ancient Conspiracy: It's revealed in the first novel that the Puppeteers secretly and also secretly . In the second novel, we also learn that the Puppeteers secretly.
 * Artificial Gravity: The Ringworld generates this using centrifugal force.
 * Author Appeal: Rishathra. Not that we're judging or anything -- all we're saying some of the books in the series have quite a lot of it. Niven reportedly wearing a shirt to conventions that says "I have sex outside my species" doesn't help. Of course, his in-story reasoning makes sense, and he restricts it to sentient hominid species...
 * Vampires aren't  sentient, but the point is taken.
 * 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".
 * 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.
 * Bizarre Alien Biology: One of the main themes of the book.
 * Bizarre Sexual Dimorphism: Kzinti females are non-sentient. Also, it's suggested at one point that puppeteer females must mate with two males in order to concieve.
 * In the second book, 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. The organs used to deposit gametes are described as being "most similar". Louis then understands why Nessus didn't want to talk about it: "This is ugly."
 * Born Lucky: Teela Brown (to the extent of being a canon Black Hole Sue), later deconstructed to hell and back.
 * On the other hand, she might not have been born lucky after all, and just looked that way for the benefit of people who were.
 * 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.
 * Consummate Liar: Almost all of the information that Halrloprillalar provided in Ringworld turned out to be untrue thanks to retconning.
 * Converging Stream Weapon: The upgraded Slaver Disintegrator.
 * Cool Ship: Anything that reaches the Ringworld from Known Space in a reasonable amount of time qualifies. Eventually the Ringworld it self 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.
 * Nessus isn't just considered insane. He is. He is bipolar, swinging back and forth between "normal" puppeteer cowardice, and periods of berserker-like bravery.
 * His insanity is infact bred for in his species. The Hindmost isn't actually in the safest position of the tribe, but the one in the best position to strike enemies following them. Puppeteers can kick a heart out the back of the ribcage with little physical effort, assuming their mental effort is able.
 * Cry Cute: "[Teela] was one of those rare, lucky women whom crying does not make ugly."
 * Dropped A Bridge On Her: Halrloprillalar.
 * 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.
 * 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."
 * Faster-Than-Light Travel: Though the Ringworld is so distant it still takes years to get there from Known Space.
 * Floating Continent: from buildings to cities.
 * Foreign Queasine: The City Builders are disgusted by Louis Wu's love of cheese.
 * Free-Love Future
 * Gambit Pileup: The third and fourth books become this when dozens of protectors start plotting against each other.
 * Gargle Blaster: The Machine People ethanol is both fuel and drink.
 * God Guise: The strategy that the characters call the "God Gambit", where they pretend to be gods among Ringworld natives.
 * Hot Librarian/White-Haired Pretty Girl: Harkabeeparolyn, if you're into rishathra.
 * 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.
 * Inferred Holocaust: The climax of Ringworld features kind of a doozy. They leave the Ring by  Apparently the author noticed this "small" problem (or a fan pointed it out) between the first book and the second, where our hero goes What The Hell, Me.
 * Although the way they get the end of the wire they have is by retrieving it from the death-trap it was used to set up. The locals used it to string up the shadow square wire at neck-height, behind the protagonists.
 * 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...
 * Luke, I Am Your Father:
 * 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.
 * Off to See the Wizard: After finishing the first book, Larry Niven realized that its plot and characters mirrored those of The 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.)
 * Older Than They Look: Louis Wu, Chmeee, and pretty much anyone else who has taken boosterspice
 * 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 Puppeteer 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 Vampires Are Different: They are non-sentient, for starters.
 * Or at least they are
 * Overly Long Name: City Builders, and races influenced by their culture like the Machine People, have names five to six syllables long.
 * 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: The Kzinti.
 * Proud Warrior Race Guy: Speaker-to-Animals (Later Chmeee)
 * 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. In a surprising case of They Just Didn't Care, 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.
 * Razor Floss: Shadow square wire; Sinclair molecule chain.
 * Really Seven Hundred 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: At the time Niven wrote Ringworld, he hadn't decided to integrate 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.
 * 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. Aparently, Louis never bothered to check into the publicly available materials on his fathers.
 * The fact that most Ringworlders pronounce Louis' name as "Luweewu" in The Ringworld Engineers implies that Louis uses the French pronunciation of his name. Ringworld's Children says he pronounces it "Loo-is."
 * The inspiration for many of the sequels was to provide explanations for some of the technical problems that other people found with the original design. (See Shown Their Work, below.)
 * Ringworld Planet: The original.
 * 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 Homind 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.
 * Sci-Fi Writers Have No Sense of Scale: Averted. Seriously averted. The scale of things is mentioned lots of times, usually in a "Holy crap, I can't believe how large this thing is" situation.
 * Not Drawn to Scale: However, 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.
 * Justified, in that 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."
 * 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: The current edition of The Ringworld Engineers has a cover painting by Donato Giancola depicting 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.
 * 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.
 * Tagalong Kid: Kawaresksenjajok.
 * Tragic Monster:
 * 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.
 * 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 room temperature superconductors, and superconductors of heat, both of which become an important plot points.
 * The General Products Hull is another example of Unobtainium. It's transparent to visible light and only visible light, and absolutely impervious to any kind of harm except outright disintegration by antimatter.
 * 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.
 * Weak but Skilled: This is generally Louis' shtick through out the series.
 * You Fail Geography Forever: 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.
 * 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.
 * You Fail Geography Forever: 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.
 * 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.