Your Mind Makes It Real

"Neo: I thought it wasn't real. Morpheus: Your mind makes it real. Neo: If you're killed in the Matrix, you die here? Morpheus: The body cannot live without the mind."

- The Matrix

You'd think that it being All Just a Dream would let you do lots of cool and risky things, since it's not real anyway, and you therefore can't get hurt.

Not so.

There's an old wives' tale which claims that if you die in a dream, you die for real. It's not exactly clear how anyone could have determined this, since the only witness would be unable to confirm it. Yet it persists, and a lot of people believe it.

So, if you're in a dream, hallucination, or VR simulation, death can be plenty lethal. By extension, if you're a hacker in a high-tech futuristic world where Cyberspace is a realistic simulation, intrusion countermeasures can kill you dead. To be fair, certain depictions of Cyberspace require users to electronically link their brains to the network, which would provide a relatively obvious threat to incautious intruders. However, even hackers who operate in worlds without such dangers may be vulnerable to seizure-inducing graphics.

Let us be very clear: there is no obvious or immediately compelling reason that dying in a dream or hallucination would actually kill you, unless you are really gullible and you live in a world where the placebo effect is much more powerful than it is in real life. Obviously, magic spells can do as they like, but the only reason that you would be actually harmed by dying in a VR simulation would be if the VR simulator was intentionally and specifically designed to murder the operator. This makes sense if it's part of a Death Trap (insofar as a death trap ever makes sense), but usually this is some commercial, publicly available system, often meant for playing games.

Often Cyberspace ICE (intruder countermeasure electronics) is said to work by channeling lethal voltages into the brain of the invading hacker, but any techhead with an ounce of sense would put at least a fuse or circuit breaker, not to mention a voltage regulator, on any line connected directly to his brain. Authors who put a little more thought into the matter who don't come up with some variant of the motif of harmful sensation imply some kind of malicious out-of-band signal which triggers a nasty (usually fatal) seizure in its victims or blows up their computer. Presumably most users do not know about such things, given their willingness to use an interface that could turn them into a vegetable or corpse at a moment's notice.

As an extension, perhaps to justify this trope, such systems often propose that the user's mind actually is inside the machine, having been literally downloaded out of his physical brain. Thus, destroying the machine would leave the user with a blank brain—but destroying the physical body might leave the mind intact to have a go at possessing someone else.

An increasingly common justification of this trope is Synchronization; directly wiring your brain to the machine gives you Technopathic Power At a Price of a potentially fried brain. Most Cyberpunk games—such as Shadowrun—use this justification, and lampshade it with safer but far-less effective interfaces which people with wires in their heads can destroy with ease.

This tends to apply to video game levels that are All Just a Dream or a virtual reality simulation as a function of gameplay: If your character dies, it's still a Game Over.

When you are Talking in Your Dreams with someone else and they go to kill you—this may come into play. This may also come into play if, in a dream, a character dies, and that character dies in real life, however, this would be an overlap with Clap Your Hands If You Believe and I'm Not Afraid of You. The Master of Illusion might use this principle to make their illusions harm victims, like making Cold Flames actually burn.

Frequently pops up in a Holodeck Malfunction. See also Self-Inflicted Hell. When your mind actually changes the physical world, it's Clap Your Hands If You Believe. If a computer generated or magical illusion changes the physical world, it's Hard Light. When you're trapped in a virtual world, and have to win or die, its Win to Exit. Compare Puff of Logic, Magic Feather.

Anime and Manga

 * The final battle in Tengen Toppa Gurren Lagann takes place in something called Super Spiral Space, the space outside the galaxies, where "recognition is given real form". In other words, whatever they imagine exists, exists. Ergo: Your mind makes it real.
 * The series BALDR Force .exe is based around this concept.
 * Played with in Suzumiya Haruhi, as part of the whole thing:
 * Averted and then played straight in Ghost in the Shell. There is no cyberspace, and one can consequently not die in it. However, since brains are computerized, minds can be deleted, partly or in whole. As a countermeasure, brains can be disconnected, and firewalls and counter-viruses ("Attack Barriers") are used and released to prevent deletion. However, deep synchronization with the brain of a dying person runs the risk of dying with it.
 * Anime subversion: In Scrapped Princess, the titular character enters a VR program to save her brother from being brainwashed, only to be promptly impaled by him when he fails to recognize her. There is a moment of shock, and then she slaps him in the face and continues to shout at him with his sword still stuck through her.
 * This is probably how the Tsukuyomi power of the Mangekyo Sharingan is supposed to work in Naruto. Itachi Uchiha uses it to overwhelm the victim's mind.
 * Taken to a much greater degree with which is a genjutsu you cast on yourself instead of your opponents which is so strong that it makes things real to everyone. It may be more of an inversion though, as it's more often used for the sake of "your minds makes anything which you didn't want to happen to yourself fake".
 * GetBackers is fond of this trope, and used it in the IL and Divine Design arcs.
 * In the .hack series, characters hit by the Data Drain attack within The World are usually sent into a coma in the real world, and are temporarily knocked unconscious at the very least.
 * Some characters eventually realize that somehow their minds are taken inside the game world, experiencing it with their character's own senses instead of being at home with a headset and game pad. Naturally, they become deeply concerned about what's going on with their physical bodies, and what happens if their characters are "killed" in this state.
 * There's a bit of question in regards to whether the player stuck in the game and the coma victim are related in that manner. Word of God has dropped that the original coma victims were placed in a coma due to noise affecting their mental state, placing their reliance of the physical body explainable only under the conceit that Everything Is Online. In the latter anime and game series, ROOTS and G.U., the danger is a.
 * Digimon Adventure: Towards the end of the second Story Arc, Local Boy Genius Izzy figures out the Digital World is a world made out of the data of the world's network infrastructure and hence all the human protagonists are more than likely made of data in that world. Although he tells everyone to be careful in spite of this new development it doesn't sink in with Tai, the goggle boy leader of the group, and he starts acting like a jackass under the flawed logic that he'll somehow survive regardless of what happens. It takes Izzy telling him that he would more than likely die in both worlds if he messed up to put a stop to his nonsense. Unfortunately, this happens just after a member of the team is kidnapped and they're about to cross an electrified gate to go after her. He loses his bravado right there and the kidnapper gets away more or less scott-free, leading to a short term Heroic BSOD for Tai.
 * Digimon Tamers: Henry and Takato manages to cross a massive expanse of water without drowning by convincing themselves that they would only drown if they thought they would.
 * Digimon Frontier: Played with when Sixth Ranger Kouichi's consciousness was pulled into the Digital World by the would-be Big Bad Cherubimon. Because of this, he's technically not there, he only believes he's there. It begins to dawn on him that this might be the case when survives several curb stomp battles virtually unscathed while his friends get more and more roughed up. Although at the end, this turns out to be an even more convoluted usage when all of the hinting about the aforementioned results in Kouichi realizing that
 * Subverted somewhat in Hunter X Hunter's Greed Island arc, in that the game's titular island IS in fact a real island that the players are teleported to when they start playing the "game", rather than a virtual world.
 * Justified in JoJo's Bizarre Adventure, where this is the power of the Stand Death 13: it pulls its victims into a dream of an amusement park and then kills them while they're trying to figure it out.
 * In a later example in the same series, the trope is used to make people believe . Yeah, didn't make all that much sense in context either.
 * Half of the Story Arcs in Yu-Gi-Oh!! are about soul-sucking Virtual Reality games. The other half are about soul-sucking millennium items.
 * Attempts of the writers to give a scientific explanation for this (Noah's brains were kept alive in a feeding, protective sphere, and directly connected to the VR world he existed in) were mercilessly shot down by the same writers when Noah happily walked off in Mokuba's body, without ever considering taking his brains with him.
 * One of the many plot points in Chaos;Head is based completely around this trope.
 * Happens in Mahou Sensei Negima!, during Negi's test to learn Black Magic. He has to fight a phantasmic version of Evangeline formed from his memories inside his head; meanwhile Chisame has to take care of him, as wounds start appearing on his body as a result of the test, and a lot of Blood From the Mouth.
 * Inverted in Higurashi no Naku Koro ni. Most of the delusions appear to be very real, even tricking the watchers/readers/players, when they aren't.
 * Justified in Yu Yu Hakusho. During the Chapter Black arc, the team comes against a young boy named Amanuma who has the ability to create a psychic "Territory" where any video game he wants becomes real, and the heroes have to play in it to survive. In his territory, everyone (Including himself) are forced to rigidly follow the rules of the game, so much so that they are forced to have Seven "players" to even enter the room. (As the game has seven playable characters) Kurama deduces that the rules are so rigidly followed, that your fate in this territory will mirror the fate of the character you represent, however this particular game supplies the player with a "Continue?" screen just before depicting the player's death, meaning as long as they continue playing, they will never die. However, he realizes Amanuma must also follow his own rules, and if they beat him and go on, then the scene where the "Goblin Master" is depicted as Dying will actually happen to the boy, forcing the group to chose whether or not to kill this one boy to save the world.
 * In Fushigi Yuugi, Tomo of the Seiryuu Seishi is the second-strongest of the group because his illusions are so convincing and complete, they can cause physical damage, even to people who are already aware that his illusions are just that.
 * Paprika has a moments where the dreams and real life can't be told apart because of this trope... Both for the characters and the viewers.
 * In Read or Die, it's commented that a major reason people don't all have superpowers is because they don't believe that it's possible to have them, and thus subconsciously reject them.
 * Averted in the sixth Detective Conan film: in the virtual reality pods everyone is set to die if they all lose, but it's separated from what they feel because of it. Even the ones who "die" in the game are clear shown to not be in any pain from the injuries which caused them to lose.
 * Hagall from Ah! My Goddess has the power to project an illusion into her opponent's mind which becomes real to them.
 * Zakuro from {Saiyuki} has the power to hypnotize people by looking into his eyes and doing just this.

Comic Books

 * Subversion: In the Doc Samson miniseries, Tina Punnett is trapped in a VR game that's been modified to cause psychosomatic damage to the player. To get out, she runs herself through with a sword, causing lots of pain but also causing the game to end.
 * An interesting variation occurs in the Sleepwalker comics from the early 1990s. When Sleepwalker, Mr. Fantastic, or the villainous Thought Police are in Rick Sheridan's mind, they can be attacked by anything Rick can imagine, in a case of making things real with his mind.
 * Uncanny X-Men #133: Cyclops and Mastermind have a sword fight on an "Astral Plane", concluding with Mastermind stabbing Cyclops through the heart. In the real world Cyclops' body slumps over and Nightcrawler loudly announces "Cyclops is Dead!" He got better by the next issue.
 * The Marvel Universe has two cases of mutants who take advantage of this:
 * Danielle Moonstar, Mirage, has the ability to create illusions based on one's fears. When her powers were temporarily boosted she could make the illusions physical, with the images being more powerful if they scared the person more.
 * Trauma was a mutant introduced during Avengers: Initiative who could become one's greatest fear. It's presumed that Trauma only gains power if his opponent fears what he's turned into, since he's been capable of turning into Thor, Hulk, Juggernaut, and several other people/creatures whose power levels are insane. However in a battle against the Hulk during the World War Hulk arc, it was discovered that if his opponents can control themselves during the fight and rein in their fears, he loses power.
 * In Scare Tactics, the "town" of Beaumont brought the band's worst nightmares and could have killed them, even though the dreams vanished when Arnie realized they weren't real.
 * In one Astro City story, the Golden Age villain Professor Borzoi uses a Belief Ray to make a giant gorilla attack the crowd at a movie theater. A side effect of the ray
 * In Hellblazer, Constantine remarks that "magic is only as real as you think it is."
 * The plague that killed the Green Martians operated this way. Hronmeer's Curse was spread psychically and preyed on the Martians' fears of fire, making them spontaneously combust.
 * One issue of Generation X had the old wives' tale quoted at the start before the team had a slasher movie marathon. The rest of the issue consists of Jubilee in a semi-lucid dream trying to wake up before combinations of movie killers and villains she'd faced in her adventures (ex. Sabretooth with Freddy Krueger's outfit) killed her.
 * In Star Wars Legacy,
 * Marvel Star Wars has a Mystical Plague called the Crimson Forever. A pair of very alien life forms communicate their displeasure over being separated by psychically broadcasting a signal that makes people fall into comas that progressively get deeper, to the point of clinical death. The bodies of victims fight back as if infected with a physical disease, and the shock of it usually makes people die. The only survivor was Luke Skywalker, who was able to make himself stop fighting and woke up when the aliens were reunited.

Film -- Live-Action

 * In Brainstorm, a character dies while hooked up to a tape that records thoughts and experiences. Someone else "watches" it, and has the exact same heart attack, dying in the process because they didn't disable the pain generators.
 * The tape also records brainwaves and some physical indicators. So playing that tape unmodified gave the watcher the same heart arrhythmia.
 * David Cronenberg's The Brood starts off with a doctor whose therapy involves making mentally ill patients make their illness a physical one, which he would then cure, hey presto reverse placebo! The titular brood is the result of a woman who had motherhood or something as part of her many issues...
 * Likewise, the Videodrome signal can induce the brain to make physical changes in the body.
 * Dreamscape, which includes a guy entering the president's dream in order to kill him.
 * Subverted (somewhat) in Inception, where dying in a dream is the easiest way to wake up.
 * Furthermore, while the human brain does not make dream death a reality in Inception, it does make pain real. Getting shot in the leg in a dream sends the same signal to the brain that getting shot in the leg in real life does, i.e. extreme pain.
 * The Matrix is the Trope Namers. Judging from Morpheus's words, (which incidentally make up the trope name and quote,) this is presumably hand waved by the fact that the Matrix simulation overwrites reality for your brain, hence your brain shuts off because it's being force-fed the sensation of death. Whether or not it was purposely designed to do so is never stated, though either way, the Machines sure wouldn't want to change it.
 * However, in The Matrix Online, safeguards have apparently been put into place that when a redpill is killed in the Matrix, an emergency switch jacks them out of the Matrix, forcing them to re-enter at a hardline after some recovery time.
 * In the original movie, Neo subverts the trope.
 * Also averted in the training programs, which are designed to show you that you can die, but without actually killing you. For example, the "jump" scenario is impossible for a new red-pill to pass, as they cannot perform Roof Hopping yet. Fortunately, the ground below is made to absorb most of the impact, only causing the trainee a fair amount of pain and wounding them slightly in the real world.
 * This happens in Gamer
 * A Nightmare on Elm Street. Freddy Krueger has the power to kill people in their dreams. Any damage that he inflicts on you in a dream crosses over into the waking world.
 * In Surrogates, originally people could operate remotely-controlled surrogate version of themselves without any risk - no damage done to the surrogate could have any lasting effect on the operator. Naturally, someone finds a way to subvert this rule, and this is when the problems (and the plot) start.
 * This is different from the original graphic novel, where there is no way to kill a person via his or her surrogate.
 * In Stay Alive, a group of beta testers realize that they are slowly dying off one by one in the exact same fashion that their avatars in the game they are testing die. It is later revealed that playing this game summons the ghost of a sociopathic killer who delights in killing you in the most horrendous ways possible.
 * The Thirteenth Floor was sneakier: you enter a virtual world by possessing one of its inhabitants, and if killed in this state, your mind dies and the possessee's mind is transferred to your body instead.
 * It was more a case that simply entering the virtual world caused the swap, with the virtual person's mind entering your real world body even as your mind entered their virtual body. No one realized this, however, because the real body usually remained completely unconscious during the process. Virtual death merely broke the connection and jarred the real world body with the virtual mind inside it awake.
 * Averted in Avatar. A side character's avatar is shown dying, and he wakes up fine, albeit coughing and very discomforted. They also apparently feel pain and other feelings through the avatar. They do have good reason to take care of their false bodies though, as they're very expensive, and take about five years to grow, so if yours dies, you won't just be getting a new one.
 * Both the avatar's death and simply being unplugged forcefully probably could cause death via heart attack, but the characters in question are healthy/lucky enough to avoid it.
 * In Dreamscape if you die in a dream - even if you're in someone else's dream - you die for real.
 * Virtuosity is not a straight example - the system is designed to train cops in combat situations, similar to the US Army's Real Life Force XXI program. The problem is that different people worked on different parts of the system, so the guys programming the virtual universe weren't informed that humans would be pitted against a Sadistic, Intelligent, and Dangerous Cheating Bastard. The Dev Team Thought of ALMOST Everything - they programmed in non-lethal simulations of being shot, stabbed, bludgeoned and bitten - but when Sid 6.7 decided to try electrocuting someone, the poor chump's brain overloaded.

Literature

 * Ursula K. Le Guin's The Lathe of Heaven both brilliantly deconstructs this trope while making it Exactly What It Says On The Tin. When the main character, George Orr dreams his dreams become reality. And it's not a 'Clap Your Hands if You Believe' manner of thing; it has nothing to do with what George believes, it has only to do with what he dreams and that can be different, bad, good and, like dreams, terribly unpredictable. For example, George dreams of a world without prejudice; and when he wakes up, there is no more prejudice in the world. Because everyone has gray, colorless skin. Everyone. It means the woman he was falling in love with no longer exists, since her color was an integral part of her being. Thus we have a man, a good man, whose dreams create reality. He just wants them to stop because his timelines are getting too confusing and sad as each morning he recreates the world. Add to that an ambitious psychiatrist who at first doesn't believe and then wants to use Orr to create a better world, aliens that were created as a result of a dreaming experiment, and you have all the parts of the waking nightmare that would occur if someone's dreams could really change the world.
 * Used several times in C. S. Lewis' The Chronicles of Narnia as a metaphor for how people "only see what they want to see" or "only believe what they want to believe." In The Magician's Nephew, said magician, Uncle Andrew, so thoroughly convinces himself animals can't talk, he really can't hear the animals talk. In The Last Battle, after being tricked along with all of Narnia into believing in a false Aslan, a band of dwarves are so determined not to be tricked again, they refuse to believe they're in Aslan's Country (Heaven), and therefore can't see it.
 * The Wheel of Time books include a special dream world that can be accessed through special artifacts, training, or blind luck. Injuries and death carry over. It even explains people dying in their sleep for no apparent cause as them accidentally dreaming themselves temporarily into the dream world long enough for something fatal to happen to them.
 * In The Hitchhiker's Guide to the Galaxy series' fifth book, Mostly Harmless, Ford enters a virtual world in which some inhabitants carry laser guns. If they shoot you, you're dead, as you're "as dead as you think you are."
 * In The Pendragon Adventure, the territory of Veelox has a virtual reality system called Lifelight that initially averts this trope. It is stated that if you die during a Lifelight "jump", you simply wake up from it. However, once the Reality Bug is introduced into Lifelight in an attempt to make it less perfect and addicting, this trope gets taken to absurd levels. Not only do you die in real life if you die during a jump, but any injuries you get appear on your real body, even damaging your clothing. And after the Reality Bug manifests in a jump as a giant shape shifting monster, it is somehow able to enter physical reality by burrowing down through the ground. Bobby even admits that all this violates the laws of physics as he understands them.
 * In G. A. Effinger's When Gravity Fails, eight people lie down at a Virtual Reality couch, and only seven get up. One of them figured a way to make one of the others fail to go back to their body, causing their "soul" to be purged when the machine shuts down.
 * In William Gibson's Neuromancer, and other stories set in the same world, console cowboys interact with computing environments through virtual reality on a deep enough level that they risk brain damage or death from tangling with the wrong entities.
 * In Tek War, failing to hack a computer system results in real injuries ranging from brain damage to death. Fortunately, most hackers can spare the brain cells lost in minor skirmishes.
 * Discworld codifies this trope to an extent, in that one of the explicit rules of the world is that belief itself is a powerful enough force that enough people believing in something can make it true.
 * In Maskerade, the villain is killed in a sword-fight, but it was stage fighting, and the sword is just held under his arm. However, he (and everyone else in the opera house) has been so immersed in drama and fiction for so long that it kills him because he expected it to.
 * Using "Headology" (directed YMMIR) is a large part of being a witch. Granny Weatherwax makes liberal use of it and promotes its use in her pupils over the use of actual magic.
 * Susan uses this trope to its maximum effect, developing her wards' belief in a poker she uses to beat up the monsters that hide under the bed, rather than telling them these monsters don't exist. That is, while she realizes nothing will make them stop believing in monsters, it's much easier to make them believe she's enough of a badass to take them.
 * In Equal Rites, Esk meets the Things from the Dungeon Dimension in her dreams, and they assure her they can kill her there.
 * Averted in Pratchett's Only You Can Save Mankind. There's a reason why Johnny Maxwell was referred to as "The Hero with a Thousand Lives" by the inhabitants of the computer game...
 * A variation: In the Ben Elton novel This Other Eden a character is killed in real life while playing a VR game; inside the game his fellow player sees his dying thoughts.
 * In Hyperion, a cyberspace hacker's head explodes when he is exposed to a section of cyberspace inhabited by AIs, which is normally inaccessible to humans. In this case, it's a completely real security system which causes his implants to boil his brain. When people are Mind Wiped during a network crash, however, that's the trope played straight.
 * Russian cyberpunk literary classic Labyrinth of Reflections used a massive VR world... based on DOOM. Considering the state of the nigh-post-Soviet information network in 1991, that makes some sense.... The trick was a hypnosis program of sorts known as Deep that put the user in a trance-like state; the relatively limited visuals they were given were filled in by the brain's natural ability to add extra data (akin to limited side effects of sensory deprivation) and an immersive world was created. The trick was a very small, professional group of "Divers" who could bring themselves out of the trance-state at will, and interface with the system as it actually existed. Also there has been made a certain virus in the Deep that actually kills the users. And one that traps divers.
 * In the third Hellgate: London novel, a demon used a device which made the target relive his/her past in the dream, which will go horribly wrong and kill them, or make them go crazy.
 * In the Memory, Sorrow, and Thorn series, by Tad Williams, the Dream Road is a metaphysical realm that is touched on by all thinking beings while they sleep, but that practitioners of the Art can enter intentionally, bringing others with them. Things that happen to one's mind on the Dream Road can and do affect one in reality, and in the most benign of circumstances it's possible for an inexperienced traveler to become "lost" and unable to return, leaving their body an Empty Shell. In less benign circumstances, there are ... things there that can actively destroy all but the most powerful minds. Such encounters are typically fatal (or worse) to the dreamer.
 * One of the central mysteries in the Otherland series, by Tad Williams, is why this trope seems to be occurring. Brown Note effects are known to exist, but they require especially high-quality virtual reality interfaces, and yet the Otherland network somehow manages to deliver sensations that the users' equipment is incapable of generating, and keeping them trapped online even when they ought to be able to simply remove their VR gear. The answer is that the.
 * In The Saint short story "The Darker Drink", Simon Templar encounters in the High Sierras a man named "Big Bill" Holbrook who claims to represent the dream avatar of Andrew Faulks of Glendale, California. Holbrook notes that Faulks had started to have an increasingly vivid recurring dream, such that smell and tactile sensation emerged. It appears that the personages in Faulk's dream (such as a woman named Dawn Winter) had started to manifest in the waking world. Templar notices curious phenomenon which seem to support Holbrook's claim: Simon sees his own reflection fine in a small mirror, but Dawn's features are "blurred, run together, an amorphous mass"; when every single character repeats the same cluster of honorific catch phrases when they first meet the Saint; and the phenomenon of time compression that Holbrook identifies as an aspect of dream (a group of thugs searching for Holbrook and Winter say they will travel a long distance to fetch their boss from the town return in less than thirty minutes). Though one of the thugs opens fire on Templar, he has no wounds in the morning. However, when he visits Glendale, California to look up Andrew Faulks, Faulks has died after slipping into a coma.
 * The main gist of the supposedly nonfiction book, The Secret.
 * One of Dumbledore's famous quotes from Harry Potter and The Deathly Hallows seems to address this trope. "Of course it is happening inside your head, Harry, but why on earth should that mean that it is not real?"
 * The Afterlife in both the book and movie versions of What Dreams May Come.
 * In a nutshell, what explains to Winston at the end of Nineteen Eighty-Four: that as long as the people believe it happened and there is no written evidence to the contrary, it actually happened, and screw the laws of nature if BB says so. In fact, the ideal citizen is one who can subconsciously alter his perception, memory, and experiences to meet whatever the Party says in order to make it true.
 * In Stephen King's IT the "it" is an Eldritch Abomination whose true form cannot be comprehended and uses the worst fears of its victims to kill them. "It" preys on children because adults are too close minded to believe what they see.
 * In the Kingdom Keepers, any injuries the Keepers suffer in their holographic DHI forms carry over when they wake up in their beds.
 * Sphere, the Michael Chriton novel (and film) has a device bestow this power on unwitting researchers sent to inspect a seemingly alien find on the ocean floor. Half are killed by nightmares emanating from themselves or someone else.
 * In Robert E. Howard's Conan the Barbarian story "Shadows in Zamboula", Zabibi is trapped in a circle of cobras, that prove illusionary in the end, but the Evil Sorcerer assures her that forcing women to dance to escape until they collapse was a common form of Human Sacrifice.
 * Magicnet falls somewhere between this and Clap Your Hands If You Believe, depending on whether you view magic as a shared hallucination, or the product of an alternate reality that coexists with this one. Characters who truly believe that magic exists can and do get hurt by it, but a large amount of what occurs is shown to be just smoke and mirrors once characters deny it (e.g. a supposedly exploding plane engine turns out to be undamaged.)
 * The mythical Tlön culture in "Tlön, Uqbar, Orbis Tertius" is capable of this.
 * In a case of "Someone Else's Mind Makes It Real", in Anne Mc Caffery's The Rowan, it was first thought that Prime level talents suffered from debilitating vertigo (known as Travel Sickness) if they attempted interplanetary travel. Then along comes Jeff Raven, an untrained Prime from a frontier colony who could bounce around with no ill effects. It was later discovered that the only one of the six known Primes that did have that condition was Siglen, who had an inner ear condition that really did cause her to fall ill. Siglen's giant ego subscribed this to "the burden Primes must bear for their power," rather than have herself checked out. Since Siglen trained or trained with all the rest of the primes, she mentally pushed her condition on the rest. The Rowan was the only one of the original five young enough to train herself past her conditioning. And then, preferred staying on her home base of Io, Jupiter's moon, unless she had to travel.

Live-Action TV

 * The X-Files episode "First Person Shooter", written by William Gibson and played for comedy, like the entire episode. A more serious version is the episode "Pusher", where a man has the ability to talk people into killing themselves in various ways. Most of the time, it's by making them do something self-injurious, but at least one of his victims dies from being given a graphic verbal description of a heart attack, and then suffering the same.
 * Also, Sliders did an episode that ripped off Nightmare on Elm Street, but with these evil nerds that called themselves "The Dream Masters". The nerds were defeated once the characters banded together, realizing that it was all just a dream, and overpowered the nerds' minds, resulting in an inability to be harmed.
 * There was a Crowning Moment of Awesome/Crowning Moment of Funny where Rembrandt is cornered by the nerds and is about to be killed. He goes, "I wish I had my gun right now." The gun materializes in his hand, and he blows a few nerds away.
 * The classic episode of the Star Trek: The Original Series, "Spectre of the Gun", has the landing party trapped in a surreal nightmare that recreates the Shootout at the OK Corral. Spock realizes the whole experience is an illusion that is only as real as their minds accept it to be, but, as McCoy says, only someone as emotionless as a Vulcan could have the iron-hard certainty required—even a shadow of doubt would be lethal. Spock mindmelds with the others to make them just as sure of the illusion as he is, making them invulnerable to it.
 * Another episode, "Shore Leave," is full of this - the landing party is investigating a seemingly abandoned planet as a possible "shore leave" destination for the crew. Except whatever fleeting thought anyone has, happens - McCoy makes a crack that the place is like something out of "Alice In Wonderland" and the White Rabbit comes bounding out complaining that he's late; Sulu spontaneously thinks of samurai and nearly gets run through BY a samurai; a female redshirt crew member jokes that she feels like it's a setting fit for a fairytale princess and suddenly she's wearing a 14th-century gown and being wooed by a knight. After later run-ins with everyone from Japanese fighter planes to Don Juan to Kirk's old college girlfriend, an old man suddenly comes running out of the bushes and explains to everyone that he is from an advanced civilization that built the planet as a sort of holodeck for themselves. He gives Kirk the thumbs-up to let the rest of the crew beam down and be their guests for a couple weeks—but just be careful what they wish for.
 * One episode of the original Twilight Zone, "Perchance to Dream", justified this: the character at risk of death was suffering from a severe heart condition, bad enough that having a particularly scary nightmare would give him a lethal heart attack. Unfortunately for him, his last few dreams appear specifically designed to give him said heart attack...
 * One episode of the most recent version (2003 series) of the Twilight Zone, aptly titled "Placebo Effect", featured a doctor dealing with a chronic hypochondriac patient. Normally keen on giving him placebos, she's horrified to find he actually IS showing signs of a terrible, previously unheard-of disease. It turns out that the disease was fictional, and after reading about it in an old sci-fi novel, the hypochondriac somehow "made it real" by believing he suffered from it. Soon, everyone in the hospital has caught the disease and appear to be near death.
 * Stargate SG-1 episode "Avatar": Teal'c gets trapped in a VR simulation that shocks him every time he dies in the game. While the simulation itself can't harm him, the continual shocks force his body to produce extra adrenaline, which eventually can kill him. He's trapped because in real situations Teal'c would never quit, and so the simulation disables the abort option.
 * It's worse than that: the simulations aren't pre-programmed, but work off the sim runner's mind. Teal'c will never quit, never surrender... He also believes, at the time, that no matter what, they can never fully defeat the Gou'auld. Meaning not only can he not just hit the off button, but whenever it seems like he's going to win something new pops up, kills him, then the sim restarts and gets harder still.
 * Stargate Atlantis episode "Doppelganger". There were other factors involved in that death....
 * Lois and Clark has an evil genius who traps the main characters in a VR system. In the end, the system is shut down while he is still hooked up (and "downloaded in"), resulting in his mind being separated from his body, and the last shot is him screaming inside a computer screen.
 * Another episode had a master hypnotist (the second master hypnotist, not the first one) whose hypnotic illusions were so real that Jimmy bumped his head on an imaginary desk and got a real life bruise. The hypnotist used this power to cause people to die from illusions.
 * Subverted in Eureka. During an episode of shared dreams, one Red Shirt died in reality and in the shared dream at the same time... but it turned out to be coincidental.
 * In VR.5, dying in VR does not kill you, but it leaves you brain-dead. (In fact, it's claimed that dying in something as primitive as a flight simulator will have this effect!)
 * Lexx: "Patches in the Sky". We're told, offhand, that "If you die in a dream, you die for real," as if it's obvious.
 * War of the Worlds: "Totally Real", the loser of the VR game lost his life—though this turned out to be the entire point of the simulator's design.
 * First Wave, a number of times.
 * Doctor Who:
 * In "The Deadly Assassin", the Gallifreyan Matrix works like this, as death in the virtual reality overloads the person's mind. (In "The Trial of a Time Lord", on the other hand, the Doctor and his opponents physically enter the Matrix. Don't ask.)
 * In "The Three Doctors" Time Lord Omega is essentially the god of an antimatter world he's imprisoned in within a black hole. Despite having been destroyed by the singularity's energy, he still exists because of his belief and desire for himself to still be alive.
 * In "The Mind Robber", it is established that the inhabitants of the Land of Fiction are, well, fictional... unless you believe in them, in which case your mind makes them real and they are able to harm you. Strangely, though, in order to get rid of a menacing fictional character, all present must vocally disbelieve. The Doctor and Zoe are able to make a Minotaur vanish this way, but Zoe's inability to disbelieve in Medusa forces the Doctor to use a mirror to defeat her, even though he knows she's fictional. Later, Zoe is forced to fight Karkus, whom she knows is fictional, because the Doctor has never heard of him and thus cannot disbelieve.
 * However, in the New Series episode "Amy's Choice", this is explicitly subverted by the Dream Lord, who explains that if you die in the dream, you wake up perfectly healthy in real life. The only risk was trying to figure out which was the dream and which was reality, because if you die in reality ... well, you just die.
 * Supernatural did this twice. The first was a demon born out of a Deadly Prank and who kept existing because of people believing in him and the second was this dream-trope in a nutshell.
 * Searies 2 of Torchwood had a villain who only existed in the altered memories of the staff. He faded from existence when they used the humorously named drug Retcon to erase their memories of the time he'd been interacting with them (all of two days, though he himself had retconned the staff's memories to include him further back. It only required 2 days erasure to get rid of him, though, because obviously the memories he put in or stirred to the surface were only that much fresh).
 * An episode of Charmed featured a man who could enter dreams, and when women rejected him he killed them there.
 * In a recent episode of Heroes, Matt telepathically enters Angela's mind to free her from her comatose state.  uses HIS telepathy to put an image of Daphne in Matt and Angela's shared mind world thingy. This imaginary Daphne stabs Matt in the stomach. When this happens, the real world Daphne, who's right next to Matt, realizes that Matt has a stab wound right where mind-Daphne stabbed him. However, when Angela (trapped in her own mind) convinces   (who personally entered her mind near the end) to free her and Matt, Matt awakes and the stab wound is gone.
 * In one episode of M*A*S*H the camp runs out of painkillers. All the doctors get together to convince the pain-wracked patients that these "sugar pills" are very new, very effective painkillers. It works.
 * It is called the placebo effect.
 * Fringe had an episode where a man was killed when a drug convinced him that an assassin was slicing his throat causing a slash through his neck to appear in real time.
 * In the season three episode of House called "Airborne",
 * An episode of The 4400 features all of the main characters being trapped in a shared dream where they had to escape from a building that was trying to kill them. This trope is brought up in that the characters don't know whether it's going to be subverted or played straight. It's
 * An episode of Medium has Alison suffer the same injuries in real life as she had in her dreams, making her afraid that she would die in reality if she were to die in her dreams. It didn't help that she was dreaming of a.
 * In Dollhouse, if, while in the Attic, you are killed in your mindscape, your body dies.
 * Despite having VR as one of the central premises of the show, Caprica is a rare aversion. The worst repercussion for dying in VR is...permadeath for characters in what's a GTA MMO. People who only exist in the VR world can't even die, as they just constantly revive.
 * It's not clear, but it might have been the case in the Tales from the Darkside episode "Seasons of Belief.
 * In 1000 Ways to Die, there is a story about a woman who had persistent nightmares of a small, demonic imp strangling her. While she thought she was being strangled in her dreams, her physical heart raced till the point of a heart attack, killing her in her sleep.

Radio

 * Adventures in Odyssey: This seems to apply to all of Whit's virtual reality inventions, the Imagination Station being the most frequently used. At least, if a hacker got a hold of the controls and changed the adventure to put you in the crossfire of cannonballs, the threat was very real, just like threats during the adventure from, say, a ruler who would have you executed for refusing to bow to false gods.
 * The Big Finish Doctor Who audio adventure "The Mind's Eye" is a textbook example, with the local flora putting Erimem and Peri into a dream-like state (the Doctor isn't ultimately that affected), where they will die for real if they die in their "dream".

Tabletop Games

 * The RPG Shadowrun uses the "lethal biofeedback" version in its cyberspace; however, a hacker can avoid the feedback by using what's referred to as a Cold ASIST interface (as opposed to the Hot ASIST interface that most deckers use). However, not only does Cold ASIST forgo all the massive bonuses to your die rolls that Hot ASIST grants, (which is why hackers use Hot ASIST, despite Cold ASIST being the default user mode for all legitimate users of neural interface technology), but all the other deckers will mock you viciously before they Curb Stomp your Nerfed tuchas. One of the major events of the metaplot had the Matrix crashing, which resulted in people either dying or suffering irreparable brain damage when their cyberpersonas were cut off from their bodies. Considering the fact that deckers directly connect their brains to the Matrix, this is at least somewhat more acceptable than other reasons.
 * Dungeons & Dragons
 * Several illusion spells function this way.
 * The Shadow sub-school (e.g. Shadow Conjuration and Shades) is "Your Mind Makes It More Real" variant -- these spells use material from the Plane of Shadow to create part-real constructs or duplicates of spells from other schools, and have reduced effects on characters that successfully "disbelieve" them and unaffected by the illusory part. Naturally, they always have this reduced effect on objects and creatures with low intelligence, such as constructs.
 * Some Phantasm spells, such as Phantasmal Killer and Weird, make you save or die upon failing the roll to disbelieve, doing nasty damage even on success. Annoyingly, Death Ward, which protects against other spells that make you save or die, won't protect you against this because it's an illusion based on fear.
 * The whole Planescape setting uses this trope along with Clap Your Hands If You Believe as its very basis. For one, some planes have "subjective gravity": whichever way you think is down, is "down", and if you don't think there are up and down, you float.
 * The Nightmare Lands domain and boxed set for Ravenloft has creepy fun with this, too.
 * One of the first Dragonlance game modules had the player characters travel into a living nightmare to end its hold over an elven kingdom. Many of the monsters the players encounter are in fact creations of the dream, and can be made harmless if players state they don't believe in them. Unfortunately, quite a few of those monsters are very real, and will attack the players anyway, and it's very difficult to tell the difference.
 * Mostly averted in Mage: The Awakening with the Astral Realms. Attacks in the Astral Realms don't harm health, but instead reduce Willpower (a person's reserve of mental and emotional strength). If a person loses all of their Willpower (not necessarily from being attacked) they return to the waking world, unable to maintain their Astral self and completely emotionally drained, but otherwise unharmed. There are however ways in which the person can be damaged or destroyed mentally. For example, being attacked by an ideology until the person's identity is completely buried beneath fanaticism, being drawn into the hold of an insanity realm until one's personality is utterly destroyed from that insanity, or going to the Dreamtime unprotected, where one's mind will be completely washed away by a consciousness which is incompressible to and uninterested in human perspective or individuality (essentially, your sense of identity is lost among the thoughts of something which has existed before there was life). In these cases, the body becomes a completely healthy vegetable. It's not entirely averted, since there are beings capable of inflicting actual damage from the Astral Realms (though this could be more to do with magically being able to target their body directly, rather than because Their Mind Makes It Real).
 * For its predecessor, Mage: The Ascension, this was the very basis of the game. Reality was defined by a popular consensus. Mages were just people who realized this and as a result could do crazy 'magic'... like build spaceships and have kung fu that breaks your mind.
 * The Digital Web, Ascension's mystical internet is very much born of the cyberspace stylings one normally finds in Cyberpunk fiction, but you can enter it. Assuming you're one of the titular mages.
 * Subverted by two small-press RPGs, Shattered Dreams and Dreamwalker: while dreaming in either game can kill you—and probably will, in the former—the danger comes from actual predatory creatures infesting the dreamworld, not from your own mind.
 * The "stigmata" enhacement to the Illusion advantage from GURPS: Powers can cause small amounts of damage to the target, but only to the point that he falls unconcious from the wounds.
 * Warhammer 40,000 has Warp, where all of mortal emotions go to become horrifying demons. That is, an untrained psyker sees a nightmare about something chasing him, a Khymera coalesces, devours him and runs off to eat someone else.
 * The deceiver can do this in a weird way. He can make the fearless run. Being fearless in 40k means "does not give a damn about being shot at and has troubles backing from a fight". So his ability to scare those without that component of the mind through some kind of mental vision would have to convince the subject they can feel fear, and/or teach one how to fear.

Video Games

 * A side quest in Oblivion deals with this concept.
 * The game BALDR Force .exe is based around this concept.
 * Inverted Trope in Psychonauts. You don't have lives; you have "astral layers", and if you run out of them, you're kicked out whatever mind you occupied back into the real world and need to restart the level. Great idea, except that it works the same in the real world, so now that doesn't make sense (Epileptic Trees say Ford Cruller did it).
 * Unless the real world ISN'T REAL. *spooky music*
 * The titular virtual reality program in Sam and Max: Reality 2.0, works like this, and our heroes take advantage of this to solve at least one puzzle.
 * Arguably used in the Silent Hill series. How much of the games is real and how much is illusion is hotly debated. It's implied that the twisted, blood-and-rust-soaked Otherworld, at least, is a kind of hallucination, especially in the first game, where it's stated that several police officers who went to investigate the titular burg mysteriously died of heart attacks. Most likely they wandered into the Otherworld and fell victim to this trope. What people are actually doing while trapped in the nightmare, however, is another matter entirely...
 * Though not really part of the main storyline, Silent Hill fans and players have created a theory that there really are no monsters or cults in the town of Silent Hill. Rather, YOU, yourself, are the monster. Even more fucked up, it was said that there are some kind of plants that grow naturally within the vicinity of the town, which induces insanity and paranoia, which makes you think that you are being chased by all sorts of fucked up creatures in the town and makes you go into a murder-spree.
 * "Monsters?" cue Slasher Smile "They looked like monsters to you?" Heather gasps, horrified. "Relax! It's just a joke!" Unless it isn't...
 * In Fatal Frame/Project ZERO 3, "The Tormented": Rei, Miku and Kei travel into the House of Sleep when they dream. If they lose all their spiritual health in the dream-world, they are confined there forever; leaving nothing in the physical world but a bunch of scorch-marks.
 * Central to the gameplay in Dystopia, where players work with each other between Meatspace (the solid world) and Headspace (Cyberspace). Headspace obstacles such as encryptions, passwords, or ICEs (Although the regular ICEs don't damage the player, and GREEN ICEs only forcibly jack the player out with an EMP) are physical to the player's avatar, and entire fights wage on in Headspace. If one dies in Headspace, they are yanked back to their physical bodies with disorientation and bodily damage (HP loss). It is also possible to sneak behind a jacked-in player in Meatspace and kill them. The player's avatar is told that their Meatsack (body) is taking damage, and death simply deletes the Headspace avatar in the middle of whatever it was it was doing.
 * Mostly averted in Fallout 3. The "Tranquility Lane" quest takes place in a virtual simulation where a Mad Scientist tortures the other inhabitants of the simulation, frequently killing and resurrecting them without serious harm to their bodies... aside from the crippling physical atrophy acquired after decades centuries in virtual reality. However, the player can
 * Played straight as an arrow in the DLC, Operation: Anchorage. If the Lone Wanderer dies in the Anchorage simulation, his/her body goes into fatal cardiac arrest in the real world. Justified by the Brotherhood of Steel being unable to re-enable the safety features in the simulation. As for why a stated training sim would have lethal settings, it's repeatedly hammered in that the head of the dev team was a nutcase.
 * In the PC adventure game Ripper, the killer known as the "Ripper" has the ability to kill anybody who once played the online game Ripper (the "Ripper" is one of the original players, the protagonist has to figure out which one of the surviving players it is). The Ripper's ability takes the form of a "software rewrite" of the victim's "brain software": the hormonal and electrical layers of the human brain. When triggered (through use of a Brown Note telephone call), the fluid and air pressure within the victim increases rapidly causing them to violently explode. The protagonist has to have his own "software" modified with an immunisation so that the Ripper can't use the "long range doohicky" any longer (he is still vulnerable if the Ripper chooses to attack him "face to face" in the virtual world).
 * Later, the Ripper calls all of the surviving characters into the virtual world, and demands the protagonist choose who they think it is. The protagonist at this point has armed himself with a single-use "virtual weapon" in the form of a pulsing orb of energy. Each of the characters make their case to the player, and the player must use the virtual weapon on the character they think is the Ripper, presumably killing them, as the ending narration is spoken in the past tense. Choose badly and not only have you killed an innocent person, the Ripper attacks the protagonist directly and kills him as well.
 * In Iji, you can "crack" computers and enemies with your nanofield, but if you fail the crack you are booted out by your target's security system with negative effects depending on the difficulty of the crack. Especially odd since it's not virtual reality. I assume the computer interface is just that realistic. On the other hand, you are standing right next to whatever thing you're trying to hack and, in fact, probably touching it, so it could just be zapping you. Also, doors mostly just increase their security, and supply crates will break or explode as retaliation, and enemies mostly just realize you're standing there and stop standing around in a peaceful manner. And maximizing your crack level removes all harmful effects of failure.
 * Weirdly played with in System Shock: being kicked out of cyberspace doesn't cause much injury, but does max out fatigue (physical exertion).
 * Max Payne and its sequel have "dream sequences" which can kill you. Inverted somewhat in that they're caused by various No One Could Survive That poisonings and injuries, so surviving them is the Your Mind Makes It Real.
 * Shadow the Hedgehog has two levels that take place in Shadow's memories, trying to help people aboard the space colony ARK, which went out of commission fifty years ago.
 * In the Nintendo game Eternal Darkness, you have a Sanity Gauge that, when low, will cause hallucinations that are often freaky, but ultimately harmless. However, when your Sanity Gauge has run out entirely, anything that would normally only reduce your Sanity will start taking chunks out of your health instead, most likely due to this trope.
 * In Kagetsu Tohya, Shiki faces two opponents. The first is his personal nightmare of his Nanaya side, a psychotic killer who is also much stronger than him. So he can't beat it because he believes Nanaya is simply better at fighting than he is. Quite justified in that the entire story is a dream of sorts that doesn't necessarily follow the Nasuverse laws of physics.
 * The plotline of Professor Layton and the Diabolical Box. The box contains some hallucinogenic gas that makes people experience what they expect, including death. This was the whole illusion of Folsense, as Luke and Layton had seen pictures of 30-year-old Folsense beforehand, and so perceived it that way when they got there. Truth was, it was pretty decrepit.
 * World of Warcraft brings us Vanessa Vancleef, who poisons your party and sends you a few rooms back, the poison causes you to hallucinate various nightmares involving past bosses, despite nobody actually being there, dying to the fire/ice/lighting/bosses themselves makes you drop dead in reality.
 * Possible example in In Famous, when heading into a tunnel to destroy a tanker of tar, at one point you begin to hallucinate, seeing enemies fading in and out of reality and much larger than they should be. But they aren't just hallucinations, as their bullets still hurt you and can still kill you.

Web Comics

 * A subversion: In a Metroid-based webcomic called Metroid: Third Derivative, Samus is "uploaded" to the Space Pirates' main computer, and put into a training simulation by a mostly-friendly pirate. Samus asks the Pirate, "And I suppose if I die here I die in the real world too?" The Pirate answers, "What? No. That's stupid and completely defeats the point of virtual training." To which she replies, "Chalk up a rare victory for common sense then."
 * Double Subverted when
 * Perry Bible Fellowship here
 * Parodied on Xkcd: "If you die in Canada, you die in real life!"
 * Irregular Webcomic does it too..
 * Housepets has an appropriately titled strip named strip called Your Mind Makes It Real.
 * This appears to be how the afterlife works in Homestuck. A person starts out in one of their memories, but once they realize it's a memory, they can do whatever they want.
 * Subverted in Ninth Elsewhere: The character who is actually asleep, Carmen, is perfectly safe inside her own mind. The muses who journey with her, on the other hand, can fully manifest themselves in her mind, and therefore can have harm done to them, and they need to eat, breathe, and sleep, unlike Carmen.
 * Gunnerkrigg Court had Zimmy, among other things, suffer fits of dragging nearby people into her nightmare. She told Antimony (naturally bewildered by her first trip to Zimmingham) "It's only as real as you let it be". Of course, this applies to what happens inside, rather than any weird stuff hitching a ride from the place in someone's head, let alone leaking out into reality.

Web Original

 * In the Whateley Universe, this is the core of the trap laid for Fey and Chaka in "It's All in the Timing", mixed with a Self-Fulfilling Prophecy.
 * But Averted Trope that one time (Ayla and the Great Shoulder Angel Conspiracy) in the holographic simulators, which only injure them because someone has tampered with the system: it's the system and the simulator suits that are injuring them.
 * The entire point of The Slender Man Mythos.
 * ...Or is it?

Western Animation

 * The Fairly OddParents, "Power Mad", also hinges on a similar plotline, though this is because the main character has wished himself fully into the game.
 * The Simpsons episode "How I Wet Your Mother" has a device that lets homers family go in his dreams. They die in the dream, they die for real.
 * Kim Possible has an ep involving a VR system, where its malfunction resulted in extreme aggression if the players were removed without winning the game.
 * Subverted in Batman: The Animated Series, "Perchance to Dream", as Bruce escapes from the Mad Hatter's dream world by deliberately leaping to his "death" from a tower, causing himself to wake up in the real world. However, in the exact same series, The Riddler hooked Commissioner Gordon up to a virtual reality computer program that could do such a realistic simulation of high-G loads, that Gordon's physical body would think it really was happening and suffer cardiac arrest. In the same episode, Riddler himself gets his brain fried when the computer crashes while he's still hooked to it.
 * In fairness, Batman had an unfair advantage; the Mad Hatter's dream world was so perfect Bruce knew it for a dream, and one too painful to continue living in. The Riddler was Hoist by His Own Petard, since the Batman villains never expect their own devices and plots to backfire on them.
 * Also, the Riddler's device was designed as an assassination tool. Mad Hatter, at least the animated version, is much less quick to kill.
 * Code Lyoko is an exception, sometimes; when Ulrich, Yumi, or Odd lose all their Life Points, they are merely rematerialized into the real world. If this happens, they simply return to the material world too weak to stand up. Also, thre's a twelve-hour cooldown between respawns. However, this return only works when the scanners that allow access to Lyoko are functional. Also, Aelita, who was tied to the computer for the first two seasons, would have been lost forever if she ran out of Life Points. Unsurprisingly, she was never actually devirtualized until the tie was broken, but plenty of times after that. Also, it appears that no matter who you are, falling into any of the Bottomless Pits surrounding the areas appears to prevent you from ever coming back. On several occasions, someone attacks their own ally to prevent this from happening.
 * Used in the climax of a Teenage Mutant Ninja Turtles arc in which the four are trapped in a memory virtual reality program. Complete with a Shout-Out delivered by Michelangelo to The Matrix.
 * Parodied and possibly subverted in the Futurama episode "Parasites Lost". When most of the Planet Express crew take a Fantastic Voyage through Fry's body, it isn't the actual chacters who go on the trip. The ship really did get hit with the shrink ray, but the people inside it are actually nanobots remotely controlled by the crew interacting with a VR simulation of Fry's innards. Toward the end of the episode, Leela chops the other characters to bits with an axe while they're all still in tiny robot mode. Immediately afterwards, we see the actual characters taking off their virtual reality equipment back at the office. When someone asks if everyone is okay, they cheerfully agree that they are.
 * Foreshadowed in a previous episode; the internet is fully VR and dying in the 'video game' section just causes extreme annoyance.
 * ReBoot: "Game Cubes" (no relation to that other game cube) randomly come down onto Mainframe and start up a game; if a Mainframe character dies in a game, they're dead (and if the User wins the game, they get nullified). On the other hand, considering that everyone in Mainframe is a "program" in the first place, and ReBoot plays fast and loose with how much of a metaphor the whole thing is, this may make perfect sense. Or not. Why would anybody play games on a computer that annihilates the programs? Who programmed that thing?
 * Someone created an operating system using Doom as a template. Processes were turned into monsters and killing them using a kill command was turned in shooting them with your shotgun. Perhaps being killed in a ReBoot game wasn't death so much as well... killing and rebooting that program so that it used up a different part of memory.
 * Or they were trying to merge MS-DOS and Linux. Your call.
 * In Teen Titans, this trope crosses with an inverted version of Clap Your Hands If You Believe in one episode. Robin is, and received real injuries as a result. Whether or not those injuries were an example of this, or merely him beating himself up while hallucinating, is not entirely explained.
 * Also, in an earlier episode, Raven causes monsters to spawn in Titans Tower because she's trying to bottle up the fear brought by a recently watched horror movie
 * This may be more of a case of Raven subconsciously summoning the creatures from whatever dimension Trigon is from, in the animated show her emotions affected her powers much more severely than in the comics.
 * So, what you're saying is, when Raven's scared out of her mind, she summons hostile lesser demons, at least one of which will take on the appearance of whatever scared her to begin with, accidentally. Right, note to fanfic authors: never expose Raven to the Slender Man Mythos.
 * Transformers Animated, "Human Error Part 2": The Autobots
 * W.i.t.c.h., "E is for Enemy", has this trope in action.
 * In Young Justice, this is what happens in the episode  when it was suppose to be   that had Gone Horribly Wrong and It Got Worse when M'Gann   that she unintentionally rewrote hers and everyone else's memories so that the team

Real Life

 * Certain Indigenous Australian tribes have a death curse for criminals that involves wrapping a piece of the cursed person's hair around a kangaroo bone and performing rituals over it. A special shaman hunter then finds the person and points the bone at them.
 * Similar claims have been made of some believers of Vodoun in Haiti and Africa. It is believed by some that Christianity has affected some people strongly enough to cause psychosomatic stigmata to form on their palms, as well (the real wounds of cruxifiction would be on the wrists, by the way).
 * Hypnotic suggestions work this way. It is possible for somebody in a deep hypnotic trance to feel things that are not present, which leads to some real-life Power Perversion Potential.
 * There's an Urban Legend about a man who was accidentally locked in a freezer of a merchandise boat for the whole length of the trip. He died of cold, but took the time to describe what was happening to him the whole time in the hope that it would help science or something. He accurately described the whole freezing-to-death process he was going through. The worst part?
 * According to Snopes, there's no evidence that this has ever happened.
 * There's an old Urban Legend that if you have a dream in which you are falling, you must wake up before you hit the ground or else you die. This isn't true, as anyone who HAS painfully died in a dream and woken later can tell you. Just because MOST people wake before they die doesn't mean they all do.
 * Based on some current theories about how dreams work, having a dream about a violent injury and waking up with pain may not actually be a case of your mind making it real, as much as reality telling your mind what to make. In such a case, you may have rolled over on your arm and hurt it, or simply twisted it wrong, and the pain generated by that action is translated by your brain into the dream image of the injury. People who have dreams of fire alarms going off only to wake up and realize their clock is ringing are experiencing the same phenomenon. On the other hand, falling in a dream and hitting the ground before waking up will feel like you just hit the ground without suffering physical damage (shock, but no pain). You may also physically fall out of bed.
 * There is a potentially fatal sleep disease known as "bangungot", "lai tai", or "pokkuri" that affects many Asian men. Survivors of this often describe it as the sensation of falling into a bottomless pit.
 * That's more a case of Dying Dream.
 * It may also be a sign of sleep apnea, which can cause you to suffocate to death. Better wake up fast.
 * More neuro-fun: Technically, all pain is in the mind (you only think it's your arm that hurts because pain is a signal that something's wrong in the affected part). All of these explanations could be equally true.
 * The Placebo Effect. Believing that you are taking medicine causes you to experience a reduction in symptoms and occasionally the cause of the symptoms.
 * It bears mentioning that Placebos have something like a 60% effectiveness rate. Even on cancer.
 * One anecdote is that a nurse in World War II had run out of morphine and had to stabilize a wounded soldier to keep him from going into shock. She filled a syringe with saline (salt water) and injected it in, telling the soldier it was morphine. It worked.
 * The really crazy thing is, the placebo effect is getting stronger. No, this is not about diseases that are neurological and therefore, sort of, "all in your head". (Which is not to say that they don't matter, but anyways...) Or at least, it's not entirely about diseases like that. Quite simply, Your Mind Is Making It Real More Easily.
 * The Placebo Effect is a major reason why medical pseudoscience like homeopathy and reiki continue to flourish despite the complete lack of supporting evidence.
 * Applied in the theological theory of Pandeism: miracles and revelations occur not because a God is watching over us and intervening, but because the Universe-creating entity has become us (and the rest of the Universe) and believers in any religion are able to unwittingly tap into their own little bit of Creator-power.
 * In general, its been proven that we're pretty easy to fool in this regard. A newer type of prosthetic limb channels physical feedback from the prosthetic to the stump. It doesn't take long for your mind to associate that stimulation with your prosthetic to the point that it feels like your actual limb. Also, VR can make you think a virtual image or a displaced image of something else is your real body. Our brains are built ready for cybernetic upgrades.
 * And for the matter, unrelated studies and effects can offer interesting insight in to how much our brain fools us. During one brain surgery, one patient felt the presence of a non-existent person 'nearby'. Follow up tests/cases shows that a part of the brain responsible for the sense of personal location within 3d space was being triggered and manipulated resulting in people sensing and seeing what amounts to classical depictions of dopplegangers.
 * Hysterical Pregnancies tend to make humans/animals experience all of the symptoms of being pregnant including an expanded stomach area as well as a baby kicking (called "quickening"). These women believe they are pregnant.
 * In the same vein is Couvade Syndrome or a Sympathetic Pregnancy where the husband will experience labor pains, cramps, morning sickness, and other symptoms of pregnancy, although a man doesn't normally believe he is pregnant.
 * It's been suggested that Grigori Rasputin, the Russian monk who gained access to the court of the Russian Empire by supposedly being able to treat the Tsar's hemophiliac son, hypnotized the boy to "cure" him whenever he was injured. Rasputin's hypnotic powers were in fact recounted by others, even hardened men like some of the Tsar's ministers. Either Peter Stolypin or Sergius Witte (this troper can't remember which) who later recounted Rasputin's attempt to hypnotize him, which was very nearly successful.
 * Rasputin's treatment to hemophilia is now believed to be far simpler than hypnotism: he told the Tsar to give up the modern medicine with his son's case, which at the time included dangerous amounts of aspirin, which today is known to actually make the effects of hemophilia worse. No wonder the boy got better.
 * Somatoform Disorders can cause this to happen. One of the earliest diagnosed Somatoform Disorders is "Conversion Disorder", which causes a person's psychological stresses to be converted into physical pain.