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[[quoteright:350:[[Webcomic/ThePerryBibleFellowship http://static.tvtropes.org/pmwiki/pub/images/Freaking_Vortex_-_2_panel_6067.jpg]]]]

->''"One day, I found a big book buried deep in the ground. I opened it, but all of the pages were blank. Then, to my surprise, it started writing itself: 'One day, I found a big book buried deep in the ground...'"''
-->-- '''Music/{{Bjork}}''', ''Bachelorette''

To understand recursion, [[DepartmentOfRedundancyDepartment one must first understand recursion]].

[[TheMultiverse Multiple worlds that exist side-by-side]] are fairly common in fantasy and speculative fiction, but sometimes things get more complicated than one [[AllJustADream dream world]], AnotherDimension, a simple AlternateUniverse, or just one ShowWithinAShow.

If the characters discover more layers within or without (or the layers are implied within the story), then you have a Recursive Reality.

{{Recursion}} is a phenomenon in mathematics and computer science where an equation refers to itself, allowing a finite function to represent an infinite set of objects. In physical terms, it is similar in structure to Russian [[MatryoshkaObject Matryoshka dolls]], which are designed to nest one inside the other.

The basic types:

* The "Russian Doll World" - the worlds are physically inside one another. The most common way to travel between them is [[IncredibleShrinkingMan changing size]]. This dates back to the sci-fi pulps of the 1930s, even though the atomic model that likely inspired this trope (where electrons orbited the nucleus like planets around a sun) had [[ScienceMarchesOn been superseded]] as early as 1925.
* The NestedStory - One of the [[OlderThanPrint oldest examples]] is ''[[Literature/ArabianNights The Arabian Nights]]''. Scheherazade [[FramingDevice tells stories]] of people who tell stories about people who tell stories, and so on. This is basically a StoryWithinAStory or FramingDevice, taken UpToEleven. (Layers deep, that is.)
* The Recursive Simulacrum, or "Matrix Hypothesis" - Building a ship in a bottle, on a ship in a bottle, basically. Someone creates an artificial world, be it a computer simulation, [[{{Cyberspace}} virtual reality]], pocket universe or a miniature planet. Then someone in ''that'' world creates another simulacrum. Bonus points if an inhabitant of the last simulacrum builds another one, or the original creator's world turns out to be a model itself. GameWithinAGame is a subtrope.
* The DreamWithinADream - A character dreams of another world, is put into a LotusEaterMachine or starts hallucinating another life, and to emphasize the drama of the situation, the character's confusion and/or the depths of their madness, the character is pushed into a layer within or [[UpTheRealRabbitHole thinks they have escaped into the real world]], only to find [[SchrodingersButterfly they are simply in an outer layer of the dream.]]
* {{Transfictionality}} - Suppose RecursiveCanon (a copy of the work itself, or a related work by the same author) shows up within the work. Then it turns out to be ''real'', because the author of the StoryWithinAStory (who may or may not be [[LiteraryAgentHypothesis the author of the actual work]]) is, in fact, [[AGodAmI God]] of his own [[{{Mythopoeia}} sub-created universe]]. May result in FridgeHorror (or regular horror if it's addressed by the plot) if the in-story author has a CreatorBreakdown. See also RageAgainstTheAuthor.

For extra [[MindScrew headache-inducing]] potential, [[{{Mythopoeia}} a creator]] might mix and match:

* [[MutuallyFictional Stable Fictional Loop]] - Similar to a StableTimeLoop but with narration instead of time travel, this can take any of the above forms and turn it into a paradox, such as a pair of {{Alternate Universe}}s that reference each other through [[RecursiveCanon recursive fiction]], usually with paradoxical {{event flag}}s that prevent you from determining which version of the story is the "outer" story, or which is the "real" story. Compare TrappedInTVLand.
* Turtles All The Way Down - It's an infinite regress; [[{{Postmodernism}} there is no "reality"]] except in the mind of one character / {{God}} / the author. No matter how far [[UpTheRealRabbitHole up or down you go]], [[ClosedCircle you can't get out]]. Perhaps they AscendedToAHigherPlaneOfExistence or they're in a DyingDream. Perhaps [[ThroughTheEyesOfMadness they're simply insane]]. If lucky, it's a [[InteractiveFiction Multi User Shared Hallucination]], not a [[AndIMustScream Solipsistic Nightmare]]. (The name comes from a famous "argument" for the TurtleIsland cosmology as an explanation for [[GravityIsAHarshMistress gravity]].)
* Single reality - There is only ''one'' world, that is somehow enclosed inside itself. Possibly in several instances.

A similar phenomenon in art and graphic design is the [[DrosteImage Droste effect]], where a picture includes a smaller copy of itself, that copy has a smaller copy of itself, and so on.

Note that there has to be more than two layers shown or implied, or a path inward must paradoxically lead to the outer world (which is closer to an actual recursive equation.) Otherwise it likely falls under one of the simpler OtherworldTropes. Shrinking into a subatomic world, for instance, does not count as a Recursive Reality unless a character can shrink further and find an even smaller world within, or somehow end up back where they started.

RecursiveCanon is a specific subtrope where the work postulates its own existence ''in-story'', or a fictional version of the author also exists ''in-story'' (allowing the characters to [[WhoWritesThisCrap criticize it or the author]] or [[RetCanon change it]], of course.) Compare MutuallyFictional.

Not to be confused with LiteraryAgentHypothesis, where the work postulates its own existence ''in real life'', or the existence of a fictional author ''in real life'' (as "researched" by the real author, of course.) Compare DaydreamBeliever, {{Mythopoeia}}.

Compare with most OtherworldTropes, particularly ExpendableAlternateUniverse, where the importance of all these alternates is downplayed by the assertion of a "real world", MatrixHypothesis (also known as [[ShapedLikeItself Recursive Reality]]), and UpTheRealRabbitHole, where the "prime" level of existence is called into question. The latter is often paired with [[DepartmentOfRedundancyDepartment Recursive Reality]] for its [[MindScrew headache-inducing]] potential. See also DaydreamBeliever, WelcomeToTheRealWorld.

Also, try to keep in mind the MST3KMantra while reading any of the examples. Believe us, it's just not worth it to lose your sanity to these. Because a recursive reality is physically impossible and never will happen.

'''[[{{Spoiler}} Spoileriffic]] trope, as the layering is usually a [[TheReveal major]] [[MindScrew plot]] [[TwistEnding twist]].'''
----
!!Examples:

[[foldercontrol]]

[[folder:Anime and Manga]]
* One chapter in YakitateJapan has Azuma pulling out a copy of the tankobon the chapter is in to show that a RealityWarper [[ItMakesSenseInContext reaction to eating nori spread]] was strong enough to temporarily change the title of the manga on the cover (which it even does in real life.)
[[/folder]]

[[folder:Comic Books]]
* The ''Marvel Vs. DC'' crossover and the ComicBook/AmalgamUniverse that resulted was explained by setting Marvel and DC continuities (each with their own fiction, past, present and future, parallel dimensions and [[{{Elseworld}} alternate timelines]]) in discrete [[TheMultiverse multiverses]] created by entities called "The Brothers". Those guys live in the "Omniverse", which supposedly contains every real and fictional universe ever.
** The Brothers are often interpreted by fans as being forms of Marvel's "The One Above All" and DC's "The Presence", each of which is {{God}} in their respective universe.
* Hasse's ''He Who Shrank'' inspired a number of similar comic book stories: ''Lost In The Microcosm'' (originally printed in the EC series Weird Science #12, 1950), ''The World Beyond'' (Strange Tales #32, 1954) and ''I Shrunk Away to Nothing!'' (Journey Into Mystery #56, 1960), the latter two published by Atlas, the predecessor to MarvelComics.
* A short ''ComicBook/DarkwingDuck'' comic published in an issue of DisneyAdventures (titled "Cogito Ergo Something") has Launchpad holding up a dandelion and positing the existence of countless Recursive Realities to Darkwing. Sure enough, the perspective changes, and we see another world inside the dandelion seed where an alien Launchpad is presumably saying the same thing to an alien Darkwing about an alien flower. Then the perspective changes to inside the alien flower, and we see the "normal" world again ([[MindScrew inside the inside]]), where Darkwing promptly blows the whole idea off as nonsense and blows the dandelion seeds to the wind.
* [[MarvelComics Marvel's]] Microverse is actually a ''subversion'' of the RussianDollWorld - originally it was treated as one of many microscopic universes, but it was [[RetCon retconned]] to AnotherDimension accessed by shrinking so far that one [[AppliedPhlebotinum crosses the Pym Barrier]]. Also, once in the Microverse, characters cannot shrink any further.
** In one tale, the cosmic entity Kubik was educating the younger cosmic entity Kosmos on the structure of the universe by ''growing'' from the mortal level through the galactic, eventually becoming larger than the universe, than larger than the trans-cosmic realm where universes exist ... only to pop ''up'' to the level of quarks, and growing up past the atomic level back to the mortal realm. As Kubik said it; "The center of the universe is wherever you happen to be at the moment."
* Creator/GrantMorrison's ''ComicBook/TheFilth'' shows several microcosm-style environments (including a city contained by an enormous ship and a miniature world populated by "[[{{Nanomachines}} I-Life]]"). The Hand's base, The Crack, is implied to be [[spoiler:a microscopic base]] created to harvest the [[spoiler: ink leaking out of the pen Greg uses to write the note for his (probably failed) suicide.]] The Crack, in turn, is home to the Paperverse, the fictional reality that The Hand mines for exotic technology.
* WarrenEllis's ''{{Planetary}}'' sums it up best itself:
** "This is the shape of reality. A theoretical snowflake existing in 193,833 dimensional space. The snowflake rotates. Each element of the snowflake rotates. Each rotation describes an entirely new universe. The total number of rotations are equal to the number of atoms making up the Earth. Each rotation makes a new Earth. This is the multiverse."
** Said by someone who developed a quantum computer in ''1945'' which uses the shape of the multiverse to compute and create situations upon their Earth to solve problems. That's right: using the entire multiverse to effect changes upon one single world within it. So fractal it hurts.
* ''ComicBook/AllStarSuperman'' shows Superman, wondering how the world will function without him, creating a miniature Earth in a miniature universe. It grows relatively quickly, and the last panel of the issue shows someone drawing a comic-book character, declaring "This time, I'll change everything..." The character is {{Superman}} - it's our world, the man doing the drawing is Joe Shuster, and we have a loop.
* The ending to ''ComicBook/{{Irredeemable}}'' is basically this: [[spoiler: Plutonian having to absorb deadly radiation surrounding Earth or be killed with a weapon so powerful it can kill him completely. After he does so his body begins to be slowly ravaged. As chance to finally redeem Plutonian, Qubit uses inter-dimensional technology to send Plutonian's original essence before his FaceHeelTurn to a parallel universe where he can end up right. As a result Plutonian's essence inspires Joel Shuster and Jerry Siegel to create Superman which in turn gets Creator/MarkWaid into comics and eventually writing Irredeemable]].
%%* [[http://www.irancartoon.com/quino/water.gif This strip]] from cartoonist ''{{Quino}}''.
* {{Fables}} mentions this trope with a side-character. A queen is punished for her infidelity to her sorcerer-king husband by being transformed into a tortoise, cursed to wander with a fragile teacup balanced on her shell, with the teacup containing the archipelago on which she grew up. Later we see a short story where there is a tradition amongst the people of the archipelago to touch the "wall" surrounding their sea, and it turns out there is a debate in their community between people who hold different views on whether the tortoise exists or not, and whether there are TurtlesAllTheWayDown. As far as the reader can tell, both schools of thought are wrong, unless it subsequently turns out that the greater Fables multiverse is on a tortoise of its own.
** ''The Great Fables Crossover'' introduces the Fables (who have long theorised that the popularity of their stories amongst the mundane humans of Earth are tied to their own power, though this has never been conclusively proven, and nobody's sure whether they exist ''because'' of the Mundies' stories, or if the Mundies have stories about them because they already existed) to the Literals (who are the embodiments of literary devices, like the {{Anthropomorphic Personification}}s of Revision, Genres, the DeusExMachina, and their progenitor, the Pathetic Fallacy, AnthropomorphicPersonification of {{Anthropomorphic Personification}}s). The antagonist of this arc is Kevin Thorn, (son of the Pathetic Fallacy, father of Revise) who, as the personification of story-telling itself, has gotten thoroughly fed up with ''his'' characters all acting on their own and making a mess of his overall story, and has resolved to rewrite things so that the entire Fables multiverse (including their equivalent of the Mundy world) never existed in the first place, but fortunately his braindead twin Writer's Block keeps preventing him from actually making the multiverse-ending flourish of his pen. The screwing around with meta-concepts, breaking of the Fourth Wall (which the Literals are aware of but the Fables aren't) and general BizarroEpisode feeling of this arc causes Bigby and Snow to make the decision to treat it as an in-universe BigLippedAlligatorMoment, and try to get back to their already-complicated lives as quickly as possible.
[[/folder]]

[[folder:Film]]
* ''Film/{{Inception}}'' has dreams within dreams within dreams (and so on) with time slowing down ''exponentially'' with depth, allowing someone to spend ''decades'' inside dream worlds. Reached MemeticMutation where all Recursive Realities henceforth are named with the meme "_____ within a _____. _____ception"
* The MacGuffin that draws Edgar Bug to Earth in the first ''Film/MenInBlack'' film is [[spoiler:a miniature galaxy]]. The final scene reveals that [[spoiler:our galaxy is just like the MacGuffin, and lies several layers down within a galaxy-orb that a universe-sized alien on a floating sky island is playing marbles with.]] (According to the makers, the ending was not meant to be taken literal, as it was simply a gag put in to explain Frank's earlier statement.)
** ''MenInBlackII'' pulls a similar gag by showing a world inside a locker where K's watch is a symbol of worship, then at the end, K shows J that ''their'' world is also simply inside a larger locker (doesn't work quite as well as the first film, [[FridgeLogic the moment you think about it]]). An alternate ending has J going on vacation and ending up on ''the world inside the locker'', being the size of its inhabitants, which implies that either there is some sort of change in size when you go through the locker door, or that the lockers are more of a PortalNetwork.
* Todd Haynes' BobDylan biopic ''Film/ImNotThere'' uses a form of this to analyze Dylan's ever-changing personality by having him [[MindScrew played by five different actors]] ([[CateBlanchett and one actress]]), each of whom's story is depicted in a different genre and visual style. Creator/ChristianBale's Bob Dylan expy has his story done in documentary style, and his character was played by HeathLedger's Dylan in an in-universe BioPic. An image of a young Bale appears in a high school yearbook of the CateBlanchett Dylan, implying that her story is another movie-within-a-movie (or perhaps a drug-induced hallucination), supported by the fact that her segment is shot in the style of [[Creator/FedericoFellini Fellini's]] EightAndAHalf. Richard Gere, playing Billy the Kid, is antagonized by Pat Garrett, played by [[ActingForTwo the same actor]] who plays a reporter who harasses Blanchett, implying that the entire story take place within her mind. [[MindScrew And that's only four of them]]... Several of the stories seem to exist within the minds of one Dylan or parallel to the events of another.
* Creator/RainerWernerFassbinder adapted Daniel F. Galouye's 1964 novel ''Simulacron-3'' into the German movie ''WeltAmDraht'' (aka ''World On A Wire'') The protagonist maintains a computer simulation of a whole city. After strange events happening in the real world it is revealed that [[spoiler:the real world is also just a computer simulation constructed in a higher plane of existence]]. The movie was released in 1973, so is possibly the first film to adapt this trope. ''Simulacron-3'' was also adapted into the 1999 American film, ''Film/TheThirteenthFloor''.
* Creator/CharlieKaufman's directorial debut, ''Film/SynecdocheNewYork'', is about a playwright who, as part of his new play, creates a life-size model of New York in a warehouse filled with thousands of actors. This model contains a warehouse, which contains another life-size model of New York, which contains another warehouse...
* Kaufman's earlier screenplay, ''Film/{{Adaptation}}'', is the result of his struggle to write an adaptation of ''The Orchid Thief'', and is about the story of a screenwriter character named Charlie Kaufman, who struggles to write an adaptation of a novel titled ''The Orchid Thief''. The fictional Charlie gives up, too, and writes a screenplay titled ''Adaptation'', which is about, well, you can probably guess...
-->'''Charlie Kaufman''': (speaking into tape recorder) We open on Charlie Kaufman. Fat, old, bald, repulsive, sitting in a Hollywood restaurant, across from Valerie Thomas, a lovely, statuesque film executive. Kaufman, trying to get a writing assignment, wanting to impress her, sweats profusely. Fat, bald Kaufman paces furiously in his bedroom. He speaks into his hand held tape recorder, and he says: "Charlie Kaufman. Fat, bald, repulsive, old, sits at a Hollywood restaurant with Valerie Thomas..."
* In the movie Film/{{Spaceballs}}, the villains actually put in a video of their own movie, and go to the scene where they are watching it, seeing an infinite number of themselves watching themselves.
-->'''Dark Helmet''': What the hell am I looking at? When does this happen in the movie?
-->'''Colonel Sandurz''': Now! You're looking at now, sir! Everything that happens now is happening now.
-->'''Dark Helmet''': What happened to "then"?
-->'''Colonel Sandurz''': We passed it.
** And after another incomprehensible exchange...
-->'''Dark Helmet''': When will "then" be "now"?
-->'''Colonel Sandurz''': Soon!
* This is the central point of ''Film/{{eXistenZ}}'' - the protagonists are confused about how many levels of virtual reality [[DreamWithinADream Game Within A Game]] there are, and what they're supposed to do to win. [[spoiler: And in the end, they ''still'' aren't sure if they're still in the game or not.]]
* ''Film/TheFountain'' is a film about a man hunting for the FountainOfYouth WhoWantsToLiveForever. It features the same two characters in three time periods. [[TrailersAlwaysLie Given that, you assume]] they succeed, and [[FinaglesLaw Complications Ensue]] when the girl gets sick and threatens to die on him due to Phlebotinum Failure. [[MindScrew But no]]: the past timeframe is the plot of a book about Tom as a conquistador, told by the dying present day wife, and Tom's character [[AscendToAhigherPlaneOfExistence Ascends To A Higher Plane Of Existence]] in the future timeframe, where he bodily intervenes in the plot of the uncompleted book. Meanwhile, the present Tom ''does'' find the [[WorldTree Tree of Life]], [[spoiler:but it's too late to save his wife]], and the Tree in question is dying, so he plants another one [[spoiler: over her grave]] where she predicts it will resurrect her as a tree...at the end of the story, the conquistador succeeds in living forever when he stabs the bark of the tree and [[spoiler: [[LiteralGenie the immortal tree consumes him]]]]. He drops his ring, a [[ItWasAGift a gift from the Spanish Queen]], which the future Tom picks up. It turns out to be the wedding ring that the present Tom had lost.
* In the movie ''Film/LastActionHero'', in Jack Slater's universe there are movies where Sylvester Stallone takes up Arnold Schwarzeneggar's roles. This is a movie within a movie within a movie. WebVideo/TheNostalgiaCritic (a fictional character) reviews the whole thing, adding another layer.
* ''WesternAnimation/HortonHearsAWho'' is about an elephant who hears voices from a tiny town called Who-ville, built on a dust mite. In the animated version, there's a {{Stinger}} where the mayor of Who-ville hears voices coming from a Who-scaled dust mite...
* In ''Film/TheThirteenthFloor'', the scientists are creating a simulation they can download their brains into. But it works both ways, the simulations can upload into the real people [[spoiler: Eventually, one of the scientists realizes that their own world is a simulation and people have been downloading themselves into him and his friends. One of the people from the layer above starts to treat him like a person when they realize he's built a new layer of this reality and he gets to upload into the mind of someone in the layer above.]]
* In ''Film/Cube2Hypercube'', Kate at one point opens a door to escape someone who turned murderer, accessing the opposing door ''from the same room she is already in''. Even the madman is a bit baffled at this.
* Experimental Soviet documentary film ''Film/ManWithAMovieCamera'' is all about this. The titular man with the camera is shown over and over again, filming the movie. At one point the film stops and reveals still images, because the editor is taking a break. Another sequence shows the editor cutting the footage together, with the resulting footage then playing. At the end an audience assembles in a theater and watches ''Film/ManWithAMovieCamera''.
[[/folder]]

[[folder:Fine Art]]
* ''[[http://www.mcescher.com/gallery/recognition-success/print-gallery/ Print Gallery]]'' lithograph by Creator/MCEscher depicts a man in an art gallery looking at a picture of a harbour. As the eye follows the scene clockwise the harbour expands into a city, which expands into a detail of a building containing a gallery full of Escher's drawings, which turns out to be the gallery in which the man is standing. The center of the picture is a blurry white spot.
** There is a documentary and a website [[http://escherdroste.math.leidenuniv.nl/ "Escher and the Droste effect"]] about an attempt to figure out what would be in the white spot. The answer turned out to be the picture itself, shrunk and rotated. Of course that image would still have a white spot to be filled with another picture...
[[/folder]]

[[folder:Literature]]
* ''ThePhantomTollbooth'' has the location of the number Infinity.
-->''The Mathemagician stopped what he was doing and explained simply, "Why, in a box that's so small you can't see it--and that's kept in a drawer that's so small you can't see it, in a dresser that's so small you can't see it, in a house that's so small you can't see it, on a street that's so small you can't see it, in a city that's so small you can't see it, which is part of a country that's so small you can't see it, in a world that's so small you can't see it."''
-->''Then he sat down, fanned himself with a handkerchief, and continued. "Then, of course, we keep the whole thing in another box that's so small you can't see it--and, if you follow me, I'll show you where to find it."''
* OlderThanPrint: ''[[Literature/ArabianNights The Arabian Nights]]'' is the TropeMaker for the metafictional version -- For example, Scheherazade tells the story of ''The Fisherman and the Genie'', where the fisherman keeps the genie from killing him by telling it ''The Tale of the Vizier and the Sage Duban'', during which the evil vizier tells his king ''The Tale of the Husband and the Parrot''.
** Spoofed by Hungarian writer Frigyes Karinthy who takes it to ridiculous levels.
** The 19th century novel ''The Manuscript Found in Saragossa'' has a similar structure -- Alphonse van Worden meets, imagines, or reads about a number of colorful characters in intertwining stories, in the course of his journey to Madrid.
* One of the simpler examples, the Total Perspective Vortex that Zaphod confronts in DouglasAdams' ''[[Literature/TheHitchhikersGuideToTheGalaxy The Restaurant At The End Of The Universe]]'' is a [[spoiler:model within a pocket universe]] within "the real thing".
* Creator/BrianAldiss' ''Report on Probability A'' presents a circular sequence of worlds. Mrs Mary is being watched by her three servants, G, S and C, who are being watched by some aliens from a parallel universe, who are being watched by scientists observing a rift in reality on the top of a hill, who are being watched by... until we come to the observers in the "outermost" reality, who turn out to be the figures in a painting in the cafe that G, S and C frequent.
* In PiersAnthony's ''Literature/{{Xanth}}'' series, Princess Ida has a tiny moon the size of a baseball that orbits around her. The moon contains a whole world with its own Ida, and that Ida has a moon with a different world on it, but that moon also has an Ida, who has a moon and so on and so on and so on. ''Faun And Games'' was about exploring these moons, and the main character goes through at least six layers.
** Actually he only went down three layers, and learned of a fourth.
** In the following book, and in many others beyond, they learn of more and more moons in the line, though past Fractal (#16) the sequence gets murky. In a recent book, Air Apparent, it turns out there is in fact a finite number of moons, and it is possible to cycle through them all the way to Earth, and now it is possible to go back to Xanth in the same fashion.
* ''HouseOfLeaves'' is about Johnny Truant, who's editing Zampanó's manuscript about a documentary made by Will Navidson. Neither the documentary nor Will Navidson exist in Johnny's universe, and they [[MindScrew may or may not exist in Zampanó's universe]]. This is the most simplified description possible.
* Creator/PhilipKDick used this in several works:
** In ''Literature/{{Ubik}}'': TheStinger indicates that [[spoiler:Runciter is in a deep-freeze afterlife just like the main cast was, and there's another version of Joe Chip feeding things down to him just like he fed things down to the "dead" Joe Chip.]] And HereWeGoAgain...
** In ''Literature/TheThreeStigmataOfPalmerEldritch'', it's an article of faith among many Martian colonists that the drug Can-D does this, rather than merely causing shared hallucinations, as most non-users believe. Things get much more ambiguous when Eldritch brings an alien drug, Chew-Z, back from the Prox system.
* Toyed with in Diane Duane's ''TheBookOfNightWithMoon''. There's a Prime Reality, but it certainly isn't our Earth, and there's nothing better or worse about a given layer. Those layers closer to the prime reality have rippling effects on the surrounding realities, especially those further down the line, though. Taking a chunk of the biggest Russian doll is bad. Smudging the paint on the smallest might be universe-destroying for the bigger dolls.
* Creator/GregEgan's ''Literature/{{Diaspora}}'' is a Recursive Reality, beginning with the computer network the posthuman protagonists live in and ending in a more or less endless number of non-euclidean universes.
* In JasperFforde's ''Literature/ThursdayNext'' novels, all the worlds of literature exist in a parallel multiverse called the Bookworld. ''First Among Sequels'' features two fictional versions of Thursday herself. [[FridgeLogic If you think about it]] the books they come from must contain ''another version of the Bookworld itself''.
** At the end, Thursday observes the remaking of the first ''Thursday Next'' book. The "on-stage" part is cut-and-pasted from ''The Eyre Affair''.
** And, of course, the "Outworld" - the real world that Thursday comes from - is a fictional world written by JasperFforde. [[ThisIsReality She doesn't think so]], but occasionally something happens to make her wonder.
* In Jostein Gaarder's ''Sofie's World'', [[spoiler:Sofie and Alberto break out of their fictional world, written by Albert Knag, into the "real" world... Which is, of course, also fictional, since it was written by Jostein Gaarder. And]] who knows how many more layers there might be...?
* One of the oldest ScienceFiction examples is ''He Who Shrank'' by Henry Hasse, originally printed in 1936 in ''Magazine/AmazingStories''. The protagonist is injected with a serum that causes him to shrink smaller than an atom, where he discovers that every atom is a solar system, with a nucleus for a sun and electrons that orbit like planets. He shrinks through several universes until he [[EarthAllAlong lands on our world]], and tells his story to a writer who unsuccessfully tries to sell the story to a newspaper as nonfiction.
** Also [[ScienceMarchesOn Science Marched On]] ''eleven years'' before the story saw print - quantum mechanics began to supersede the Bohr-Sommerfeld orbital model as early as 1925, although the Bohr model is still taught today because 1. it accurately predicts the behavior of hydrogen atoms and 2. [[LiesToChildren ease of depiction]] (subsequent models are heavy on equations and don't actually ''look'' like anything.)
** One of the ''ChooseYourOwnAdventure'' books did that too, but with ''quarks'' as ''universes''.
* ''[[http://qntm.org/?responsibility I don't know, Timmy, being God is a big responsibility]]''.
* Creator/StephenKing's [[Literature/TheGunslinger first]] ''Franchise/TheDarkTower'' book implies that Roland's universe is a Recursive Reality, specifically an atom in a blade of grass in our own universe. Later books muddle this somewhat.
** In later books, you find out it also counts as {{Transfictionality}} and RecursiveCanon. So the universe is in a blade of grass in another universe, ''written by the author''.
** More specifically, the Dark Tower setting is more like a mobius strip of recursion, wherein our world simultaneously contains and is contained within Roland's universe, each being both lesser and greater than the other. The Dark Tower tends to be somewhat insanely metaphysical.
*** The atom-in-a-blade-of-grass thing was never established to be definitely true; more the the Man in Black was just asking Roland to ponder all the infinite possibilities of creation. The whole thing was just a diversion to fuck with Roland's head and get him good and confused while the Man in Black slipped away unnoticed.
*** But the Dark Tower canonically manifests in our world (or a similar parallel universe) as a single, perfect rose on an empty lot in Manhattan.
* ''Literature/TheCyberiad: Fables for a Cybernetic Age'' (1967) by Stanislaw Lem has a robotic prince trapped in recursive virtual dreams by his EvilChancellor. Once the prince realises what happened, he panics, and desperately tries to wake up "for real" -- and at one point ''he does'', but, thinking in his panic that he is still dreaming, ''keeps trying'', thus falling back into endless recursive dreams [[AFateWorseThanDeath forever]].
** This happens in a [[ShowWithinAShow story within a story within a story]].
** In one of the Lem's ''Literature/TheStarDiaries'' story, Ijon Tichy visits the scientist, professor Corcoran, who build numbers of electron brains. Those electron braines closed in the chests have '''consciousness''' and they are thinking that they are real people. Chests are wired to the device which sends electric signals to those brains senses imitating perception of real world. Those brains have no clue about their real situation. Except one, who is called by Corcoran 'his world lunatic'. Because of some world imperfections (such as Deja vu or theory of Seriality), this brain suspected that it is not real and everything is just illusion which is ''served'' to him by someone or something. At the end of conversation, professor Corcoran admits, that he is also suspecting that he is not real and surrounded by phantoms, products of false signals sended to his senses and that it is probable that even creator of this world is also a chest in someone laboratory, and so on and on...
* In Creator/CSLewis' ''TheChroniclesOfNarnia,'' all universes are connected to the Wood Between The Worlds, a forest dotted by pools. Each pool serves as a portal to a universe.
** And when Narnia is [[TheEndOfTheWorldAsWeKnowIt destroyed]], a whole copy of it is inside a barn - plus a copy of the 'real' world. And when the characters in Narnia go to the apple garden, there's another Narnia inside it, and everything gets more beautiful and ''real'' as they go inward.
* In the JohnCrowley novel ''Little, Big'', the world of the Fae is smaller than the human world and exists in cracks and crevices of the latter. By the time a slow-motion EndOfAnAge comes around, [[spoiler: the Fae have abandoned their world, apparently for another, smaller one, and the few humans aware of the Fae have taken their places in the Fae world.]] The further in you go, the bigger it gets.
* In the ''Science of Literature/{{Discworld}}'' novels, the wizards create a "model universe" they christen Roundworld. Roundworld is, of course, our world - which implies that eventually Roundworld will contain an author named Creator/TerryPratchett who will write stories about a Discworld in which wizards create a Roundworld, etc.
** At the end of the first ''Science of Discworld'', Hex actually states (er, writes) definitively that recursion has in fact occurred.
** Another Literature/{{Discworld}} example, this time from the main series. In ''Sourcery'', the main characters have to travel across the Circle Sea, and do so in the djinn's lamp being carried by one of the characters, which they still have in their hands ''inside the lamp''. This only works because one of them is carrying the lamp and is moving... because they are inside the lamp being carried. It stops working when the universe realises what's going on, so they are told not to think it through, leading to one of them doing exactly that...
* Not exactly "literature", but the Australian picture book ''Puzzle Worlds'' is based on this. A gaggle of hapless airline passengers find themselves in a world inside a well in a town on a flea on a zoo animal... and various nested worlds inside ''that''.
* In a story in ''Bigot Hall'' by Steve Aylett, the protagonist and his friend go out to a small island in the grounds of his home. The first thing they find is a tiny fence, when they tread on it, and then a model of the hall, including a little lake with another, even smaller model of the hall, which has a tiny lake with tiny model...and at this point they freak out, fearing that if look up they'll see giants above them. His father finds them later (hiding under a tarpaulin), and says he knew they were out out on the island when he saw that part of the fence had been flattened.
* ''Literature/{{Flatland}}'' contains Lineland inside it, which contains Pointland inside it. It is itself contained in Spaceland, which may be contained in a higher dimension. So, while there are only 2 recursions inward, there may be an infinite amount outward.
* There is a story called "Fessenden's Worlds" by Edmond Hamilton, where a scientist creates a miniature galaxy to experiment upon. After he's killed (along with the galaxy), a friend of his, who saw it all, keeps thinking "is there a Fessenden out there"?
* A Soviet story "Engineer Alexeev's Mistake" is about a scientist who created a tiny galaxy orbiting Earth. When some time later he decides to shut it down, it turns out that due to time passing differently there, the galaxy has already developed an advanced civilization (with a communistic government, naturally), and managed to retaliate by putting the scientist in stasis.
* A rather famous Russian poem from 1922 ''Atom'', later republished as ''The world of an electron'', by Valery Bryusov starts with "What if those electrons // are worlds with five continents, // arts, knowledge, wars, thrones // and memory of 40 centuries?" The idea seems to have been quite widespread back then.
* Creator/RogerZelazny's ''Literature/TheChroniclesOfAmber'' uses this, with Amber (and, it's implied, one ''location'' in that world) being the ultimate physical manifestation of an ordered reality. All other worlds are shadows of Amber, or shadows of shadows, or so on recursively... all the way down to pure [[OrderVersusChaos chaos]], near which the worlds are so volatile you can often just walk from one to the next. [[spoiler:Then it turns out Amber itself is a reflection of a still deeper world, containing the pattern Oberon created. Then Corwin creates ''another'' pattern, and, it's implied, another multiverse. Then it gets complicated.]]
* ''Literature/CloudAtlas'' is a series of nested stories, told in different stories, through different mediums (a log book, a screenplay, a spoken story, etc) which abruptly end part way through as the next story begins. Each of the main characters will at some point actually find the previous story, get to the point where it was cut off, and for one reason or another be unable to finish it either. Only the "center" story is unbroken, and as it finishes the others are picked up again and one by one finished.
* Creator/RoaldDahl uses this trope a few times, most notably in ''The Wonderful Story of Henry Sugar''.
* Lawrence Miles's ''Franchise/DoctorWhoExpandedUniverse'' novels contain frequent references to the "bottle universes". The intent appears to be that the Literature/DoctorWhoNewAdventures universe exists in a bottle in the Literature/EighthDoctorAdventures universe ... and vice versa. {{Mind Screw}}y enough on its own, other authors (who believed both book series were in continuity with each other) muddled things even further, eventually establishing it was a Klein bottle, and the universe was inside ''itself''.
* [[PostModernism Subverted in]] Creator/JorgeLuisBorges short story '' "Averroe's Search" '': In the last page, Borges realizes that he has broke the [[MutuallyFictional StableFictionalLoop]] and incurred in an [[OntologicalMystery Ontological Paradox]]
--> I felt, on the last page, that my narration was a symbol of the man I was as I wrote it and that, in order to compose that narration, I had to be that man and, in order to be that man, I had to compose that narration, and so on to infinity.
* In ''TheEnduringFlameTrilogy'', Tiercel proposes that the worlds are each nested inside the other like a puzzle box. When "lined up" properly, something can move from one world to the other.
* ''Literature/TheDresdenFiles'': At one point, Harry made a scale replica of Chicago, with a powerful spell on it. When he uses it, he "enters" the model, and is able to move around it. And through it, he can observe things happening in the real Chicago. One unnerving aspect of the spell is that if he looks up at the sky, he sees the interior of his own basement, and a giant size version of himself concentrating intently on the spell.
* The plot of the BerniceSummerfield novel ''Dead Romance'' uses this trope for some hardcore {{Mind Screw}}ery; the protagonist discovers that she is from a Universe-in-a-bottle created by the Time Lords, and the reason her (and by extension, ''our'') universe is so [[{{Muggles}} mundane]] is that the Time Lords didn't have enough material handy to recreate all the crazy aliens that humanity in the "proper" universe seems to run into every week. A visitor from the outside universe is astounded that the Pyramids were actually built by humans instead of AncientAstronauts, for example.
* A very wide variety of examples can be found in Douglas Hofstadter's book ''Gödel, Escher, Bach: an Eternal Golden Braid'', in which recursion and self-reference, particularly applied to mathematical proof about the nature of mathematical proof, are major themes.
* "Worlds Apart" by Richard Cowper. It begins with Universe A being a story in Universe B and vice versa. And that's just the begin of the {{MindScrew}}, when the universes begin to interact...
* In ''[[http://www.scribd.com/doc/87940745/Ivan-Kireyevsky-The-Opal The Opal]]'', a king receives a magical ring containing [[{{Astrologer}} his own star]]. It shows him a planet of incredible beauty, so he spends all the time there, with a beautiful girl, [[LotusEaterMachine to the exclusion of all else]]. Later, he exchanges the ring for a kiss from the girl, ''with her promising to use the ring in order to visit him in turn''. [[spoiler:By the end of the story, she is yet to follow up on the promise.]]
[[/folder]]

[[folder:Live Action TV]]
* The ''Series/StarTrekTheNextGeneration'' episode "Ship In A Bottle", where the Professor Moriarty created on the holodeck to outwit Data is discovered to be sentient and demands that the Enterprise crew work to transfer him into their world. Data later discovers that [[spoiler:Moriarty appears to exist outside the holodeck because he actually exits the holodeck on an Enterprise he created within the holodeck on the "real" Enterprise. They make Moriarty think he receives what he wants by transporting him to the simulated holodeck, which runs a simulation of the Enterprise's shuttle bay that makes it seem as if he and his companion are free to explore the universe.]] As if that wasn't headache inducing enough, Picard wonders aloud whether the "[[UpTheRealRabbitHole real world]]" could be yet another simulation, which prompts Barclay to test his hypothesis.
** His exact words are, [[LeaningOnTheFourthWall "All this might just be an elaborate simulation running inside a little device sitting on someone's table."]] After he leaves the room, Barclay nervously says, "Computer, end program." The episode ends there.
* In ''MorkAndMindy'', Mork once shrank down to microscopic size and ended up in an alternate world.
* The ''Series/DoctorWho'' serial "Castrovalva" features a variation on this, where the entire town (a town called Castrovalva) had been warped in on itself. One of the cliff-hangers had a hilarious line from the Fifth Doctor.
--> '''Doctor''': Recursive occlusion! Someone's manipulating Castrovalva! ''We're caught in a space-time trap!''
:: The deliberately over-the-top delivery of that line was lampshaded in the "Castrovalva" commentary where Davison described it as "end of episode acting".
** The entire premise of the ''Series/DoctorWho'' episode "Amy's Choice" is a choice between two possible realities in which they keep falling asleep and "dreaming" of the other world, in which they are entirely convinced they are in the "real world" again. [[spoiler: Turns out both scenarios are dreams, but there is a brief moment that could be an UpTheRealRabbitHole situation.]]
** Then there was [[http://www.youtube.com/watch?v=51JtuEa_OPc the time the TARDIS]] [[http://www.youtube.com/watch?v=RkmiefoRcfU ended up inside the TARDIS.]]
* In the ''Series/BuffyTheVampireSlayer'' episode "Normal Again" Buffy is poisoned by a demon that makes her hallucinate that she's in a mental institution, and has been [[CuckooNest hallucinating her life as a Slayer in Sunnydale]].
** That presumes that Buffy would have to be in every scene, but in "Normal Again" she not only goes unconscious in the first few minutes but the asylum continues to exist when she is not present. It could simply be that Buffy is the grand creator of the ''entire'' Whedonverse, which is not a stretch considering we only see one-hour glimpses into her life at any one time and there is magic in the Whedonverse than can create a lifetime of false memories. [[spoiler: Dawn is actually the product of such magic.]] Anyway, due to some intense backlash, WordOfGod is unlikely to be trustworthy at this point.
** OR maybe there are two realities - one where Buffy's crazy and the other where she's the slayer - that just crossed paths at that point in the timeline before splitting again.
* ''AmericasFunniestHomeVideos'' had a clip of their dog reacting to the show. Later, a different family sent in a clip of their dog reacting to that dog reacting to ''AFV''. Even later, the family that sent in the first clip sent in a clip of their dog reacting to the other dog reacting to itself reacting to ''AFV''.
* Despite multiple concrete examples of crossovers that put ''{{Victorious}}'', ''DrakeAndJosh'', ''Series/ICarly'' and ''{{Zoey101}}'' in the same NickVerse, Victorious as part of one episode refers to DrakeAndJosh as a TV show.
* Abed tries to do this via a film project in ''Series/{{Community}}''. It doesn't work.
-->'''Shirley:''' I'm reacting the way the world does to movies about making movies about making movies! I mean come on, Charlie Kaufman, some of us have work in the morning, damn!
** In "History 101", Abed has trouble facing the last year of classes, so he retreats to his HappyPlace, a stereotypical sitcom version of the show complete with LaughTrack. Then when things start changing there, he retreats to a ''second'' happy place, a cartoon called ''[[{{SpinoffBabies}} Greendale Babies]]''. So to recap, Abed has a happy place ''within'' his happy place.
* In ''Series/CosmosAPersonalVoyage'', Creator/CarlSagan speculates that our universe could be the equivalent of a subatomic particle inside a "superuniverse".
* ''Series/{{Bones}}'' is loosely based on a series of novels by Kathy Reichs. The titular Dr. Brennan is loosely based on a younger version of Reichs herself. Both versions are forensic anthropologists, like Reichs, but only the TV version is the successful writer of a series of novels featuring forensic anthropologist Kathy Reichs. Instead of her the novels being loosely adapted into a television series on FOX, there's eventually a movie in the works (with an even younger, sexier, more action-oriented plot). No word yet on whether Reichs' Brennans' Reichs will have written any books.
* In one episode of ''Series/MythQuest'', Alex gets into a myth by touching a reflection of himself in a mirror in the portal. When he touches the mirror to get back to his world, he actually gets back to a version of his world that isn't quite right. He has to touch the mirror again to get to the real version of his world.
[[/folder]]

[[folder:Music]]
* In TheBeatles song "Paperback Writer", the singer tells a publisher that he wants to write paperback books, and that he has just written a book about... a man who wants to write paperback books.
* The cover of the Music/PinkFloyd album ''Ummagumma'' is a photo in which a variation on the same photo is hanging on the wall, which itself contains a variation on the photo and so on in a modified DrosteEffect.
* The video of Music/{{Bjork}} song [[http://www.youtube.com/watch?v=XJnhaXwK86M Bachelorette]] is this in spades (especially so as it was made by Creator/MichelGondry). After finding a book in a forest, which begins authoring the protagonist's thoughts, Björk's character gets it published, gets a theatre adaptation, and then begins acting out the story. When the play hits the adaptation part, the show then becomes a play-within-a-play, and continues looping into itself. In the end, [[spoiler:everyone turns into plants for some reason, which ends up burying the book again.]]
* The video to [[Music/PeterGabriel Peter Gabriel's]] [[http://www.youtube.com/watch?v=Qt87bLX7m_o ''Steam'']] begins with the view of space and stars with Earth closing in and ends with zooming in on somebody's skin, brief glimpse of cellular structure, DNA, individual atoms and interatomic space [[RecursiveReality which becomes the interstellar space again]].
[[/folder]]

[[folder:Newspaper Comics]]
* In a reversal of the ''He Who Shrank'' scenario, [[CalvinAndHobbes Calvin]] once grew to the size of a galaxy and finds a door that leads back to his own room.
* A ''PearlsBeforeSwine'' comic strip featured Pig meeting [[CriticalResearchFailure Atlas who held the Earth on his shoulders]]. Pig then points to the part of the Earth where he is, and his giant hand comes down and pokes his eye.
* ComicStrip/{{Dilbert}} had to deal with a guy so cocky, he thought [[http://www.dilbert.com/2011-02-07/ he was the one holding up the infinite turtles]].
* In an early ''FoxTrot'' SundayStrip, the very strip's splash panel can be seen on a newspaper that Roger is reading.
[[/folder]]

[[folder:Pinball]]
* Creator/WilliamsElectronics' ''Pinball/TalesOfTheArabianNights'' requires the player to venture into seven of the Tales and retrieve a magic jewel from each one. One of these is "The Tale of Scheherazade", who is the narrator of the ''Arabian Nights''...
[[/folder]]

[[folder:Professional Wrestling]]
* Similar to the 'hall of mirrors' effect, anytime the camera faces the titantron, showing the camera feed, the image will appear to form a self-replicating hallway. It's more noticeable during long promo segments when the attention is diverted towards the stage area. This effect also pops up during video games.
[[/folder]]

[[folder:Tabletop Games]]
* The farming board game ''{{Agricola}}'' features several different "Room" tiles, in of which a game of Agricola is being played (a few posts down [[http://www.boardgamegeek.com/thread/352362/humor-on-the-agricola-card-artwork-includes-compar here]]).
* One of the Activity cards in the card game ''ChezGeek'' is a "Stupid Card Game", and the art for the card is a bunch of geeks playing a game of... ''Chez Geek''.
* One campaign for ''TheDarkEye'' featured a pocket dimension containing an archipelago on whose islands certain legends were true. One suggested subplot depended on one character dying there; their soul would be transported to, and be able to have encounters in, another dimension while the rest of the group was supposed to find a way to bring them back. (This is ''not'' the norm in this game system; mostly, dead means dead.) It was mentioned that if the soul was swallowed by a certain kind of monster, it would be thrown into a realm even further removed, from which they could not be brought back.
* The 1st Edition ''DungeonsAndDragons'' modules ''I6: Ravenloft'' and ''I10: The House on Gryphon Hill'', could be played either as stand-alone adventures, as an adventure and its sequal, or as interlocked adventures in which [=PCs=] who retired for the night in one module would wake up in the other, and vice versa. This last option could be played as a recurring ItWasAllJustADream, as a recur''sive'' DreamWithinADream, or as the result of genuine shifts between realities.
* Malfeas in ''TabletopGame/{{Exalted}}''. When the Exalted overthrew the Primordials, they needed some way to imprison titanic beings the size of mountains and planets somewhere far away from Creation. Their solution: turn them all inside-out; imprison Malfeas, the Demon City inside the body of Cecylene, the Endless Desert; then imprison all the other Primordials, ''including'' Cecylene, inside the body of Malfeas; finally, boot them out of Creation into a separate dimension. Even this was considered too insecure for one Primordial, who ended up imprisoned inside his own wings. Understandably, they're a bit miffed.
* One adventure for the appropriately-named ''OverTheEdge'' suggests that the gamemaster swipe a small item off the table that the players will miss but not worry too much about. The object then shows up in the game world and proves to not ''quite'' follow the laws of physics. This can potentially escalate to the player characters arguing with the players.
[[/folder]]

[[folder:Theatre]]
* The final scenes of the play ''Stones in His Pockets'' concern the main characters trying to get producers to look at a script they wrote, called "Stones in His Pockets."
* ''[[TitleOfShow [title of show]]]'' is a musical about two guys writing a musical about two guys writing a musical.
** "A, D, D, D, D, F-sharp, A... will be the first notes of our show..."
* The Romanian play ''Jonah'' is about a man trying to cut himself out of the stomach of a fish, only to find that said fish has been swallowed by another fish. In the end, he finally realises that the whole world is made of fishes, and he just wasted his entire life trying to escape, instead of living normally.
[[/folder]]

[[folder:TV Tropes Wiki]]
* At the amazingly fast rate we're adding tropes to this site (as well as [[JustForFun some other stuff]]), this site will [[BlatantLies soon contain all]] the tropes that could possibly exist (and those that can't either). But if we put all the tropes that (don't) exist together, we are, in fact, describing the universe (and, indeed, [[TheMultiverse all possible universes that can and cannot exist]]), so effectively, this site will contain all the universe within it, including this site! Which, in turn, will contain this site within it, and this site will also [[RunningJoke contain this site within it]], ad infinitum. How's that for a MindScrew?
** Of course in actual fact it's a bit more of a moebius strip than universe-contained-universe: You just get through the entire site and the last page link you back to the first. It only really counts if pages start referencing the different layers of meta-reality that would be in play, otherwise Occam's Razor suggests that since we can only see one universe, there is no logic in assuming there's a second one.
* Recursive Reality: click it and see what happens.
* If you click on {{Transfictionality}}, Recursive Simulacrum, MatrixHypothesis, RussianDollWorld, or TurtlesAllTheWayDown, (all of which are found on this page), they lead you back to this same page.
[[/folder]]

[[folder:Video Games]]
* During the board game battle between the two Bonapartes in ''VideoGame/{{Psychonauts}}'', you can shrink down and travel on an enlarged version of the board game. This allows you to look inside the windows of the prop houses on the board where, in one house, you can find the two Bonapartes playing the board game!
* In ''VideoGame/{{Fallout 3}}'', this is the basis of the Church of Atom, a cult that worships the "creative" power of nuclear bombs--they believe that every atom is an entire universe and the splitting of atoms equals the birth of whole new universes and, well, just don't let them near your nukes.
** Nobody ever explain fusion bombs to these people. It might spark a holy war.
* At various points throughout the ''Franchise/{{Pokemon}}'' games, the player will encounter {{NPC}}s who themselves are playing ''Pokémon''. Presumably, these games also contain [=NPCs=] playing ''Pokémon'', and so on.
* In the Sierra point-and-click game ''Torin's Passage'', the worlds are all physically nested within each other, and accessible through warp gates called Phenocrysts. The worlds all have their own atmosphere and sun except The Null Void, so it's not clear if the worlds exist within the same dimension.
* In ''VideoGame/KingdomOfLoathing'', part of a side-quest introduced as a cross-promotion for the MC Frontalot album ''Zero Day'' involves shrinking down and fighting scabies (skin mites) ''on your own leg.''
** The Crimbo 2010 event lets you work in an office that gradually increases your Boredom. Get it too high and you might face the Tome of Tropes, get it to 100% and your character starts playing the Best Game Ever.
* External Gazer, one of the "Snake Tales" included as a bonus in ''VideoGame/MetalGearSolid2: Substance'', revolves around the use of the virtual reality system that is the in-universe explanation of the "VR Missions". It turns out that not only does it work by [[spoiler:locating a parallel universe matching the training scenario and projecting the user's consciousness into the appropriate inhabitant of that universe]], it's also possible for the "simulations" to be nested. Plus, they're nested such that [[spoiler: the player must exit the nested simulation as though exiting that component of the game itself]]. It pretty much bends the fourth wall into the shape of a Klein bottle.
* In ''VideoGame/SimCity2000'', one of the articles in the in-game newspaper is about schoolchildren learning about city management by playing a Sim City-like game. One of the students interviewed for the article wonders if they're actually just characters in a game like the one they played...
* TheStinger of ''VideoGame/SuperMarioGalaxy2'' (which is shown after defeating [[BigBad Bowser]] in the final level for the second time), actually reveals that the game's events are all part of a storybook Rosalina was reading to the Lumas. While Mario and Yoshi are both flying through space rescuing Peach and the Power Stars from Bowser.
** And then Rosalina writes herself into her own story about the game where she gives Mario the final Power Star.
* In ''VideoGame/{{Minecraft}}'' there are people who have built working computers ''in the game itself''. It has been speculated how long it will take untill we're playing ''Minecraft in Minecraft''.
** [[http://www.youtube.com/watch?v=GwHBaSySHmo It begins]].
** The mod [=ComputerCraft=] includes a text-based version of ''Minecraft'' as part of the default operating system, entitled ''Adventure''. If you 'craft computer', the program crashes because you "tore a hole in the spacetime continuum". Meaning the program on the computer in the Minecraft world, not the program ''running Minecraft'' in the first place.
* In ''Assassin's Creed Revelations'', Desmond is in the Animus living Ezio's memories, who uses the [[PlotCoupon Masyaf Keys]] to live Altair's memories.
** And ''VideoGame/AssassinsCreedIV'' implies that [[spoiler:the reason Desmond himself is in third-person is because someone else is reliving his memories through the Animus]].
* Part of the plot of ''Imperishable Night'', the eighth game in the ''VideoGame/{{Touhou}}'' series. In order to avoid discovery emissaries from the Moon, lunarian refugee Eirin Yagokoro hides the Earth in a magic pot with a fake sky on the inside. She then hides the pot in her home of Eientei. Which is on Earth. Which is hidden in the magic pot.
* In ''[[VideoGame/ASuperMarioThing A Super Mario Bros X Thing: Prelude to the Stupid]]'', one level leads the player outside an apartment, inside of which [[LetsPlay/{{Raocow}} some guy]] is implied to be doing a LetsPlay. [[http://www.youtube.com/watch?v=MqRjOYNu-fw&t=5m35s The recursion comes from the fact that the game was created specifically for this guy to do a Let's Play of]].
** In ''Make A Good Level X''[[note]]A level designing contest hosted by the forum that did ASMBXT, with the same intention (having it being Let's Played by raocow), but which got so many entries that it actually got its own hub level[[/note]], the arcade in the HubLevel has two arcade machines which are being played by other characters. One of them is ''Make A Good Level X'', which is being played by LetsPlay/{{Raocow}}.[[note]]The other one was ''A Second Mario Bros X Thing'', which is being played by its own main character.[[/note]]
* In ''VideoGame/LuigisMansionDarkMoon'', there is one room in the second mansion (don't forget, this is a HauntedHouse) with a dollhouse with windows you can look through. If you do so, you see the very room that contains the dollhouse, with Luigi looking through the window. The one difference is, one of the boxes in the scene you see is shaking. When you stop looking in the dollhouse, ''that'' box in the actual room is the one you have to look in to find the ghost that is hiding.
* This is mentioned in one of the "news" feeds in ''VideoGame/CookieClicker'' when the player has advanced far enough.
--> ''"The universe pretty much loops on itself," suggests researcher; "it's cookies all the way down."''
[[/folder]]

[[folder:Web Comics]]
* ''Webcomic/CochleaAndEustachia'' has objects [[spoiler: (including one of the protagonists)]] containing entire living rooms complete with furniture and occupants.
* ''Webcomic/DarthsAndDroids'' has no film version of ''StarWars'' in its world, with the plots of the movies used for a TabletopGame instead. In that world, however, there is a webcomic about a world that has no ''Film/HarryPotter'' movies, with the plots of ''those'' used for a TabletopGame. The layering goes down and down and down, with another movie added every 50 strips.
** Getting very meta with [[http://www.darthsanddroids.net/heists/0050.html this installment]], based on ''{{Inception}}''.
* [[http://www.sjgames.com/pyramid/iwc/?strip=26 Pyramid-exclusive Irregular Webcomic #26]] features multiply-nested RolePlayingGames.
* In ''Webcomic/{{Homestuck}}'', the Battlefield, Skaia, is contained in the King's scepter. Said king is fighting on the Battlefield. And there are two kings.
** Every single universe is apparently a giant frog.
** [[spoiler: Snowman's heart contains the troll universe, she is currently inside the troll universe.]]
** [[spoiler: Not to mention that [[BigBulkyBomb The Tumor]] is a bomb using the death of two universes as a catalyst. The two universes are the Troll universe and the Human universe, both of which are contained within it.]]
* The page pic is from a ''Webcomic/ThePerryBibleFellowship'' strip in which an astronaut [[http://www.pbfcomics.com/94/ somehow lands on his own helmet]]; when he takes it off he can see a miniature figure of himself standing on it holding a miniature helmet with an even smaller figure of himself standing on it holding...and to make his day even worse, his bald spot is spreading.
* There's a one-off joke in ''Webcomic/ElGoonishShive'' where the AuthorAvatar is actually [[http://www.egscomics.com/?date=2003-04-17 a character in the comic strip created by Sarah]].
** Also there is [[http://www.egscomics.com/sketchbook/?date=2008-01-02 this]] sketchbook which features the three original main characters (plus the Goo) viewing the first strip.
* In ''Webcomic/KoanOfTheDay'', the tortoise [[http://www.koanoftheday.com/13/ finds himself in a recursive thought]].
* ''Webcomic/{{xkcd}}'' plays with this a few times; see, for example, [[http://xkcd.com/244/ recursive roleplaying]].
** No matter how into model trains you are, [[http://xkcd.com/878/ don't make a scale model of the area it's in]].
* ''Webcomic/{{Sinfest}}'' plays with it: [[http://www.sinfest.net/view.php?date=2012-06-25 a devil scientist field-testing an Illumanti drone discovers God's field-testing him.]]
* Let's see the ''{{Franchise/Buildingverse}}'' (so ''Webcomic/{{Roommates}}'', ''Webcomic/GirlsNextDoor'' and ''Webcomic/DownTheStreet'' and their [[RecursiveFanfiction assorted fanwork]]) is a {{Megacrossover}} MetaFic 'verse, where the (for them) real stories of the characters, are fictional (so all the responsible people exist. James already placed Creator/OrlandoBloom as his problem with Legolas), that is fictional in [[RealLife ours]], and the cast [[MediumAwareness knows]] [[NoFourthWall this]]. This isn't even accounting for all the {{Dream Within A|Dream}} {{Dream World}}s TheFairFolk can create from the inside, or the possibility for stories being MutuallyFictional, or the ability to travel to the worlds of other fiction (Jareth even managed to "fix" ''Film/{{Inception}}''[[note]]So according to this there is a missing scene, where he brings forth the canonical ending, because Saito messing with his love interest's dreams from Limbo annoyed him.[[/note]]). And don't let us get started on the implied possibility to read the comics [[RecursiveCanon in the comics]]. Is there a true reality? Does the chain of fictionality ever end? We don't know. [[BreakingTheFourthWall You reading this]] [[FridgeHorror could be fictional in some other world/story too]]. ... And this isn't a twist ending, this is one of the most basic facts about these comics. Also the authors read each other's work, and some even TVTropes. So questions, ideas, characters etc. flow kinda free between the worlds making up the 'verse. At the end it's either AllFictionIsRealSomewhere or an exceptionally pretty [[SchrodingersButterfly Butterfly]]! [[MindScrew Or both]].
* ''Webcomic/{{Drowtales}}'': One of Kiel'ndia Vel'Vloz'ress' [[{{Cloudcuckoolander}} many]] [[BreakingTheFourthWall quirks]] is her belief in the "infinity turtle".
-->'''Chirinide:''' If the netherworlds aren't populated by demons, then what is it to you!?
-->'''Kiel:''' Turtles.
-->'''Chirinide:''' TURTLES?!
-->'''Kiel:''' Yup, turtles all the way to infinity.
* In ''Webcomic/LarpTrek'', some of the characters in the RPG are future versions of people playing the game, in reference to characters crossing over between ''Series/StarTrekTheNextGeneration'' and ''Series/StarTrekDeepSpaceNine''.
[[/folder]]

[[folder: Web Original]]
* WebVideo/TheNostalgiaCritic once reviewed the movie ''Film/LastActionHero''. He is a fictional character who is watching a movie featuring a fictional character who watches a movie about a fictional character who has movies featuring fictional characters portrayed by Creator/ArnoldSchwarzenegger.
* The ending of ''Machinima/RedVsBlue: Revelation'' leaves room for the interpretation that the entirety of the ''Recollection'' trilogy is [[spoiler:a [[MatrixHypothesis digital world created by some version of Epsilon where he lives out the rest of his life in a memory (including the part where he created a digital world).]]]] [[WordOfGod Burnie Burns]] stated in an interview that the setting of ''Blood Gulch Chronicles'' was real, but deliberately left the rest open to [[WildMassGuessing debate]].
* From StuartAshen: [[http://www.youtube.com/watch?v=LM7_36SP1tA this wall in a pub]] (0:26 may startle you).
* [[http://www.newgrounds.com/portal/view/600022 Macrocosm]] is an animation about a scientist who creates an infinitely-recursive chain of identical realities, only to realize that he is part of the chain himself. [[spoiler: It doesn't end well.]]
* The Wiki/SCPFoundation has a page of ThisVeryWiki [[http://www.scp-wiki.net/scp-4445-j right here]].
[[/folder]]

[[folder:Western Animation]]
* ''WesternAnimation/JohnnyTest'' has an episode similar to "He Who Shrank" - Johnny shrinks to smaller than a quark, and it turns out that each quark is an entire universe.
* ''WesternAnimation/{{Futurama}}'': In "The Farnsworth Parabox" our heroes end up owning a box that contains the universe that contains them.
** In another episode, Amy plays a game of virtual virtual skeeball-- a simulation of a game of virtual skeeball.
** In yet another episode, Leela experiences the Dream Within A Dream type. She slowly realizes she's in a dream (or going insane) and keeps trying to escape only to end up in more bizarre situations. She meets Fry each time who tells her she needs to "wake up". Turns out [[spoiler: she was in a coma, and she was hearing the real Fry (at her bedside) pleading with her to "wake up".]]
* ''WesternAnimation/SouthPark'' uses the fourth type for one episode. In the end, it turns out that Stan has emotional problems, so he, Kyle, Cartman, and Kenny (who didn't technically die this time) go for ice cream. The end.
* The short film ''The Killing of an Egg'', by Paul Driessen. A man hears a voice coming from the soft-boiled egg he is cracking and maliciously crushes it. He then hears knocking outside his house, and finds that [[KarmicDeath he is now the one being crushed.]]
* A CouchGag on ''WesternAnimation/TheSimpsons'' begins with a reverse AstronomicZoom from the Simpsons' couch to outer space, revealing it to be an atom in one of Homer's hairs.
--> Homer: "...Wwwwoooow."
** WordOfDante says that it was a parody of the 1977 short film ''Powers of Ten'' (watch it [[http://www.youtube.com/watch?v=0fKBhvDjuy0 here]] if you like), and that Homer was thinking of it, it was not in an atom in Homer's hair, it was his thoughts.
* ''WesternAnimation/TeenTitans''
** One episode had the characters being imprisoned by Mumbo in his magic hat. Cyborg points out that Mumbo, appearing in the world inside the hat, is still wearing his hat. Which everyone is still inside. Including Mumbo. And his hat.
** One Creator/KidsWB ad for the show has Robin and Starfire sitting on the couch in front of the TV. Starfire asks Robin what he's watching; he says he's watching ''Teen Titans''. Zoom out to show a recursive image and Starfire asking Robin the same question. They do this enough times to put it ''barely'' short of an OverlyLongGag, then Starfire BreaksTheFourthWall, asking the audience what ''they're'' watching.
** In the episode "Nevermore", Cyborg and Beast Boy are sucked into Raven's magic mirror, which transports them into her mind. The weird part of this is, Raven herself is somehow able to go there. Meaning she's ''inside her own mind''. She doesn't explain how that's possible, and they don't even question it. (Likely because there's a much bigger problem - [[GodOfEvil Trigon]] - threatening them.)
*** An even weirder part of this was how Raven told them they'd be trapped there forever if she was beaten (the reason she pleaded with them to leave). Given that they're inside her mind, it isn't known exactly how it's possible that the place could even still exist if she were killed (assuming that's what she meant by "beaten").
* The ''WesternAnimation/AdventureTime'' episode "The Real You."
* The song "Yakko's Universe" from ''WesternAnimation/{{Animaniacs}}'' had the entire universe turn out to be inside Yakko Warner's snowglobe ''twice''.
* An episode of ''WesternAnimation/IAmWeasel'' revolves around Weasel, Baboon and Red Guy trying to find out where everybody in the world has gone to, leaving every public place empty. It turns out everybody is home, watching ''I Am Weasel''. And yes, it DID in fact include a shot of Weasel in front of a TV showing him in front of a TV showing him in front of a TV showing him... To be honest though, this wasn't [[WidgetSeries even one of the]] [[MindScrew weirdest episodes]].
* In one ''WesternAnimation/SpongeBobSquarePants'' episode, [=SpongeBob=] is made to go on forced vacation, so he consoles himself with the Official Krusty Krab Playset. Toy![=SpongeBob=] ends up accumulating too much vacation time as well, so ''he's'' forced to go on vacation, resulting in Toy![=SpongeBob=] playing with Toy!Toy![=SpongeBob=] and... yeah, the real [=SpongeBob=] decided to cut it off there.
** In episode "Truth or Square", [=SpongeBob=], Patrick, Squidward, and Mr. Krabs go to Krusty Krab Surveillance Room when trying to find a way out of the Krusty Krab duct system. One of the video feed they watch is showing they watching the video feed. Then it is revealed that [[BigLippedAlligatorMoment the surveillance room was recorded by two fish who appeared out of nowhere and run away when noticed]].
* An episode of ''WesternAnimation/{{Chowder}}'' opens with Chowder eating a gumball with muffled screaming being heard as he chews it. At the end of the episode, when Chowder has gummed everyone and everything on the planet together the planet gets eaten by another Chowder and similar screaming is heard.
[[/folder]]

[[folder:Real Life / Other]]
* Infinite [[http://www.youtube.com/watch?v=WAJE35wX1nQ Fractal Zooms]], such as [[http://www.youtube.com/watch?v=2tRdLD6vh3g Mandelbrot Sets]] "Bigger than the known universe!" Turn on the [[MushroomSamba Mood music]] when watching these... ''Schpongle'' perhaps.
* There are any number of magazine covers with a DrosteImage -- where somebody on the cover is holding a copy of the magazine with the cover that they're in, etc. [[http://www.radiotimes.com/content/features/galleries/christmas-covers/22/ Here's an example]].
** Hell, ''Games'' Magazine made a '''puzzle''' out of it.
** Numerous commercials have used a similar effect, where a photograph in one scene expands and animates, becoming the ad's next scene. Usually, this also has a photo or other image in it, which also expands and animates...
* [[http://en.wikipedia.org/wiki/Raelism Raëlians]] believe that our universe is a tiny particle within the body of a living creature in a much larger universe, and that all atoms in our universe also contain smaller universes similar to the one we live in.
* The TurtleIsland cosmology is the basis for the famous often-cited [[TheWarOnStraw "argument"]] / joke / thought experiment in cosmology and metaphysics known as [[http://en.wikipedia.org/wiki/Turtles_all_the_way_down "Turtles All The Way Down"]], see that other wiki for details:
-->'''Man #1:''' If Earth is the back of a giant turtle, then [[GravityIsAHarshMistress what's holding up]] the ''turtle?''
-->'''Man #2:''' Don't be a fool. It's TurtlesAllTheWayDown!
* Have two mirrors face each other and look at what you see in them.
** Or for a hi-tech version, hook up a video camera to a monitor and point the camera at the screen.
*** Who cares. [[http://www.youtube.com/watch?v=et_MmlTxMXA Go here.]] ''Right-click download'' and Save as '''''OR''''' you can go over here oh! Can we watch ourselves? Will it let us do that on here OH MY GOD
* The Universe has about the size and mass of a ''really big'' black hole (which need not be very dense). It is therefore conceivable that black holes contain universes. (The border of our Universe would therefore be its event horizon.)
** A related fact: Objects in space tend to gather into groups due to gravity, like planets around starts, whereas stars gather into clusters, clusters into galaxies, and galaxies into superclusters. Basically the only thing that isn't a group held together by gravity of its components is the universe itself. This also works in subatomic level. To what extent, we can only guess.
** Gravity does not apply on the quantum level, and the universe isn't much of a "thing" beyond a hole where everything else is.
*** Gravity '''does''' apply on a quantum level, but it doesn't apply significantly, and the other forces typically overwhelm any influence it has.
* Philosopher Nick Bostrom [[http://www.simulation-argument.com/simulation.html has proven]] that if there's ever going to be a recursive simulation of reality, then we're probably in it already.
** This is related to the notion of [[{{Transhuman}} Transhumanism]] and the "Omega Point" theory that technology and human awareness is accelerating exponentially toward an Omega Point where we will be aware of all things in existence. Somewhere a Statistician is Crying...
* There was this [[DistractedByTheShiny animated ad years ago for something or other...]] anyway, there's this piano melody. And we see the pianist. Pull out, he's in a bubble, pull out, gets eaten by a fish, which is in a little boy's bathtub, which is in a house, in an apartment block, in a city, on a magazine cover, being read by an Arab on a camel, which is actually on a stamp on an envelope, being delivered by... and on and on until it's all in a little girl's toy city and ''that damn piano melody stops.''
* The Internet, perhaps. If nothing else, it can, and possibly should, be seen as a world within a world.
** As seen by web archive sites, the Internet also contains (incomplete) copies of the Internet, making it partially recursive.
** These days, there are many, many social networking websites. To get into it, you typically have to sign up. Those who don't sign up don't see what's happening in those websites. It's thus an internet inside the internet ('sup dawg). This is a problem for search engines, who want as much information as possible from everywhere on the internet. Apparently, this "hidden web" phenomenon is disturbing enough for Website/{{Google}} that it's criticizing Website/{{Facebook}} for exactly that.
* [[{{Emulation}} Emulators and virtual machines]]. [=VirtualBox=], for instance, simulates one PC within another PC; it's great for playing with different mutually incompatible PC operating systems or for completely isolating applications in one "box" with another. In fact, it's possible to run [=PocketNES=] (a NintendoEntertainmentSystem emulator for GameBoyAdvance) inside [=VisualBoyAdvance=] (a GBA emulator for PC) inside [=VirtualBox=].
* In case you're worried about the universe exploding by paradox, here's another thing to worry about: does the set of all items that do not belong in a set include the set itself?
** It does in exactly half of all possible sets.
* in [[http://www.youtube.com/watch?v=TtHO4AtVSwc this]] video someone uses the embedded web browser in Second Life (textured to an in game laptop no less) to access a remote desktop viewer, which they use to.....log in to Second Life
** So would that be ''Third'' Life?
* [[http://www.tofslie.com/hey/wp-content/uploads/2008/07/recursive.jpg This photo]] is a partcularly clever example. Look ''closely''.
* Google recursion.
* There is a gif that shows a spacecraft speeding towards a Death Star-esque surface. But the surface is recursive, so it never actually gets there.
* [[https://www.youtube.com/watch?v=7QkLpOkVMi4 This video]] is what happens if someone tries to use screen-capturing software on itself.
[[/folder]]
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