A Glitch in the Matrix
Neo: Whoa. Deja Vu.
Neo: A black cat went past us, and then another one that looked just like it.
Trinity: How much like it? Was it the same cat?
Neo: It might have been, I'm not sure.
Morpheus: Switch! Apoc!
Neo: What is it?
Trinity: A deja vu is usually a glitch in the Matrix. It happens when they change something.
When one enters a Lotus Eater Machine, an explicit part of the trope is that the world is composed of one's mind, like a completely lucid dream. So naturally, details don't transfer over well. So, if one sees a salt shaker disappear where you could have sworn you saw one, someone's shadow doesn't look quite right, or people are just plain acting out of character, you know that something's up. This is a type of Glamour Failure.
Anime and Manga
- In Paprika, Dr. Chiba realizes that she's still dreaming when the paraplegic Big Bad walks towards her.
- A couple of The Animatrix stories are built around this, most notably Beyond.
- In Gurren Lagann, a couple of these (and the help of one dead guy) allow Simon and Yoko to realize what's going on. It's one of the most tragic parts of the series.
- Fate in Magical Girl Lyrical Nanoha A's realizes almost immediately that she's trapped in a Lotus Eater Machine since her dream had her living happily with her older sister Alicia, a detail that simply couldn't be because Fate is Alicia's clone, specifically created by her mother as a Replacement Goldfish after Alicia died.
- In S-Cry-ed Kazuma realizes he's being brainwashed after Unkei flubs characterization in the Lotus Eater Machine he's trapped Kazuma in, by having the jerkass rival Ryuho act like they're friends after they fight and settle the score. He probably should have known better; Kazuma enjoys the challenge of fighting Ryuho but completely hates his guts for additional unrelated reasons and everyone knows what a dick Ryuho is.
- Unkei also exemplifies Small Name, Big Ego and is a total hack. His second attempt, on Ryuho this time, goes just about as well and is just as corny.
- In Yu-Gi-Oh! 5D's, Jack gets pulled into a Lotus Eater Machine by Dark Signer Carly, who is attempting to distract him while she wins their duel. He believes it for a while, but realizes something is wrong when he notices that her glasses are still in the same place they were before the duel began.
- Persona 4: The Animation When Yu is dragged into Shadow Mitsuo's Lotus Eater Machine, he catches on that something is up when he tries to put his hand in the TV and it no longer works. With the deception revealed, Shadow Mitsuo reveals itself and starts giving him one hell of a Hannibal Lecture.
- During Grant Morrison's run on Justice League of America, Batman was able to deduce he and the rest of the League had been placed in a dream state because, while he looked like an active elderly man, he had the vital signs of a younger, unconscious man. Unfortunately, the Genre Savvy villain's evil scheme was built on the JLA escaping the Lotus Eater Machine.
- In Paperinik New Adventures' second series, the titular character is unwittingly placed in a virtual reality environment. He notices something is amiss when the same background characters begin appearing in very different roles, and his suspicions are confirmed when he finds out that several different packets of potato chips contain the exact same chips, down to the one weirdly shaped like a fish.
- The Trope Namer is, of course, The Matrix. As Trinity explains, Deja Vu is caused by a glitch in the computer simulation, which usually signals that the programs running it have altered some fundamental law. In this case, all the windows and doors have been filled in with bricks.
- All over the place in Inception. Dreamers build the dream world and can alter it at will, but each alteration from the baseline helps tip off the subconscious that someone's hijacked the dream. This is why it's so important to go in with a complete picture of what the world is supposed to be. Dreamers also carry special totems whose properties are known only to them, to help them discern dreams from reality.
- Robert Heinlein's short story "They". A man realizes that something is wrong with the world when it's raining when he's outside his house, but when he goes upstairs and looks through a window it's clear and sunny.
- In The Wheel of Time, people in the World of Dreams will sometimes notice details change. However, quite often they don't notice, and the change is written in subtly enough that the readers don't notice either.
- In Time Out Of Joint, by Phillip K. Dick, the protagonist believes he lives in an idyllic American town in 1958, but then... strange incongruities begin to occur...
- It is stated in Hyperion that any attempt to simulate a human personality in virtual space ends when the mind notices the trope (which seems to always happen even with the best computers). Because at that point, the mind goes mad.
- In the sci/fi novel Resonance obsessive compulsive office messenger Graham Smith has lived his entire life experiencing glitches in the matrix varying in size from street names suddenly changing to a childhood friend's dead parents suddenly never having died, and believes that the universe unravels every time he breaks his OCD routine. It is later revealed that he switches bodies with a parallel universe version of himself every time he makes a decision as a result of being the only person who is exactly the same in every single universe
- Labyrinths of Echo series had a few of these, as dreams and semi-realities are an important part of the series. The most blatant one happened when Numminorikh was placed in a crafted dream supposed to be completely immersive, as a part of his training. The subject of the exercise neglected to mention his unusual nature (having extremely developed sense of smell), and the dream was scripted too much and used natural for normal humans focus on visual impressions, so despite high quality it was "real" only until he remembered how things are "supposed to" be.
- It's less than reliable in general, however, in that past can be almost as elastic as future, in a less-solid reality it's just more obvious. And Max, for one, cannot be trusted to retain his eye colour anywhere.
- What tips House off to the fact he's unconscious and hallucinating in the second season finale: first the case gets even more bizarre than usual, then he starts knowing things before the team tells him about them. Finally he starts noticing the scene transitions and time lapses.
- In the Doctor Who episode "Forest of the Dead", this happens constantly when Donna is "saved" in the computer's Lotus Eater Machine. Because the computer is so short on space (more than 2000 others are stuck in there with Donna), it compensates by skipping any and all transitional material. This results in Donna experiencing "dreamlike" passage of time, in which stating or even thinking of her intention to go somewhere results in her instantly being there, leading to a few seconds of disorientation before false memories of the lost time take effect. However, the glitch that finally clues her in (as pointed out by the Nightmare Face-bearing, formerly dead Miss Evangelista) to the nature of her reality is the fact that, while taking her two children to the playground, she sees that every boy and girl at the park, looks, sounds, and is dressed exactly the same. The effect is unsettling.
- This trope gets parodied in "Amy's Choice", where the Doctor and his companions are attacked by the mysterious 'Dream Lord', who only has control over dreams. The TARDIS team are forced between two realities (Leadworth, where Amy is pregnant and they're being attacked by Killer Old People, or a broken TARDIS where they're dying of hypothermia). The Doctor urges them to try and work out which reality "doesn't ring true". Rory then points out that he's currently in a time-machine with a bow-tie-wearing alien, so that might not work very well. Played straight in the end, though. Once they've correctly chosen the TARDIS as the 'reality', the Time Lord turns the ship back on, saving the characters. Except that the Dream Lord has no physical body, so the Doctor realizes they were both dreams.
- In Lois and Clark, Clark realises he's in a virtual reality after noticing that the crowds are made up of only a few different people, repeated over and over.
- An important aspect of of Lost's flashsideways alternate timeline/afterlife is characters noticing something's up. Jack has a recurring cut on his neck and scar on his side that he can't place—both were suffered during the final battle with Smokey; the latter wound ends up being fatal. Charlie has a flash of Claire while choking on a heroin baggy. Kate gets deja vu when she sees Jack. The flashsideways as a whole serves this purpose for clever viewers who may notice minor characters, locations, or scenarios repeating themselves slightly differently.
- In the series finale, each character has a revelatory montage where they remember their island life. When speaking to Locke, Jack has a brief flash of the two looking down the hatch and freaks out. When he finds Kate, he has a couple flashes of their romance and decides to go with her to learn the ultimate truth: he's dead.
- Star Trek: The Next Generation:
- "Ship in a Bottle". Data realizes that the ship is a holodeck program because Geordi is left-handed in the program, but right-handed in real life.
- "Future Imperfect". Commander Riker is trapped inside a Lotus Eater Machine. Each time he realizes something is wrong due to flaws in the illusion, the setting changes to a new illusion.
- "Parallels" employs a similar premise. Worf begins to notice that small details are off from how he remembered them—the placement of decorations, the positions where people are standing, and crew members' clothing. As the episode progresses, the differences are magnified to the extent that Picard was killed at Wolf-359, Riker is captain of the Enterprise, and Counselor Troi is Worf's wife. Rather than being trapped in a Lotus Eater Machine, it turns out that Worf is shifting through increasingly divergent parallel universes.
- In a Deep Space Nine episode, Dr. Bashir also realizes that he's in a hologram when "O'Brien" doesn't correctly know how he injured his arm. From this, he realizes that Sloan from Section 31 is playing tricks on him. In another episode, he realizes that he hasn't left Sloan's mind after having entered it with O'Brien after noticing a memory of his cycling back at the limit of his knowledge.
- A Star Trek: Voyager has the crew being put to sleep by a race that prefers to exist in a lucid dream-like state. However, since their bodies are vulnerable in this state, they attack any "waking" race they encounter. Chakotay, being a Magical Native American, has plenty of experience with vision quests and has a device meant to put him into a controlled lucid dream. Before entering the lucid dream to meet the aliens, he conditions himself to see one such glitch, namely the image of Earth's Moon in place of any planet. Tapping a finger on his other hand three times is supposed to bring him out of this state. There are several examples in the episode when Chakotay thinks he's out of the dream... only to see the Moon again. The last time, the tapping trick doesn't work, as the aliens have adapted the dream.
- Referenced in Red Dwarf. After realizing the crew are in an AR simulation, Kryten uses the fact that Cat was able to solve a cryptic clue as proof of that.
- Farscape had three.
- "A Human Reaction": the aliens can only recreate people and environments that John Crichton has seen before. Once he realizes that everything and everyone in the Lotus Eater Machine of the week is familiar to him, a trip to the ladies' room brings the illusion crashing down.
- "Won't Get Fooled Again": This time Crichton has wised up, and knows it's a hallucination, but the ladies bathroom trick doesn't work. He first realizes that Harvey, Scorpius's neural clone, isn't part of the illusion. Harvey alerts him to the fact that he is a prisoner of the Scarrans, whose intense body heat John can feel through the illusion. The hot flashes therefore function in this episode as "Matrix Glitches."
- "John Quixote": Crichton makes the mistake of playing a buggy VR game based on his own memories; once he leaves, he finds that Scorpius has taken over Moya and is brainwashing the crew against him. However, Crichton eventually realises that he's still playing the game when he finds one of the game's hint vouchers in his pocket. Plus, because the memory copy was made over a year ago, Sikozu and Noranti are nowhere to be seen, and nobody knows anything about Aeryn's pregnancy.
- Sam Tyler tries to invoke this this in the first episode of Life On Mars. Suddenly dropped in 1973, and thinking he must be dreaming, he sets out to walk until his mind runs out of detail.
- Played with in the pilot of Alphas: Hicks begins hearing random people telling him that "it's time to kill" and to "pull the trigger", but while he does think this is strange, he never suspects that he's brainwashed. The real purposes of these phrases is to show the viewers that his mind has been messed with.
- Adam Savage of the MythBusters once (during the "Cabin Fever" myth) told a story of a time he seemed to be piloting a crashing plane:
"I was up at the front of the plane, and I said, 'Listen, I don't think this is a real plane crash, since I happen to notice that I'm not wearing any pants, and when I'm not wearing pants, it's probably a dream.'"
- This is a game mechanic in Professor Layton and the Diabolical Box. You can take photographs of areas and find small discrepancies between the picture and the area in front of you. These discrepancies are evidence that you're having a gas-addled hallucination.
- In the Digital Graphic Novel re-telling of Metal Gear Solid, Snake sees Ocelot with two arms (after the Cyborg Ninja cut off his right arm) and realizes he's in a Psycho Mantis-induced hallucination.
- In Metal Gear Solid Mobile there are blue bug icons in various places in the game that you can take pictures of with the camera, that disappear after you take the picture (you get a reward for finding them all). It turns out that the mission is a computer simulation created by the Patriots.
- This happens during the Fade dream sequence in Dragon Age: Origins. Depending on which party members you bring along, the Warden, Morrigan, and Sten will all realize they're in a dream when the inconsistencies start adding up.
- Morrigan in particular seems to have noticed almost immediately, because by the time you find her she's yelling at the demon about what he's gotten wrong. (Specifically, the demon portrayed Flemeth as a broken-hearted old mother wanting the ungrateful Morrigan's love. The real Flemeth is caustic in speech and would not resort to wheedling. The demon does slap Morrigan in the face once, Morrigan thinks that is more accurate.)
- Then there's the Warden's own dream sequence. Duncan is alive, when he got Killed Off for Real at the end of the prologue.
- The other Companions besides Morrigan and Sten have to be broken out of their dreams by the Warden's interference, rather than realizing the inconsistencies on their own. Shale is frozen in place; the Warden simply has to remind it that it's a living golem. Dog doesn't have a dream; it's just wandering around waiting for the Warden. Zevran dreams he is being tortured by Crows again like he was when he was initiated; with enough persuasion the Warden can remind Zevran that the glitch is that Zevran is already a Crow, so this nightmare makes no sense. Alistair dreams he is living with his sister, Goldanna, and they're a big happy family. The Warden can point out a glitch in the matrix with enough persuasion if the Warden reminds Alistair to think about how he got here; it makes no sense that he was in a tower fighting a demon and suddenly he's with his family. Wynne dreams all of her students are dead, herself having failed to save them. With enough persuasion, the Warden convinces Wynne that the truth will make sense if Wynne believes the Warden and nothing else is real. That causes Wynne to realize something is clouding her mind. Oghren dreams he is being constantly mocked by other dwarves, and must drink ale to drown out their voices. The Warden can persuade Oghren that since he is a warrior, he can show them who he really is. Finally, Leliana dreams she is back in the Chantry praying along with her Mother. The Warden can remind Leliana of the Maker's vision that caused her to leave at first, so it makes no sense that Leliana would still be a Sister.
- In the sequel, Dragon Age II, there's a twist on this trope in the "Night Terrors" sidequest: you have to help an NPC, Feynriel to be precise, break out of the illusions instead of yourself. There are two: The Pride Demon tempts Feynriel with a vision of himself as a heroic savior of the Dalish elves with the aid of benevolent demons, and the Desire Demon tempts Feynriel with a vision of himself being accepted by his human father, Vincento, who in reality abandoned him and his mother. The bottom dialogue options tell Feynriel outright that he is dealing with demons, but this frightens him into wanting to be made tranquil. Hawke can also play along with the demons using the middle dialogue options, but Feynriel will be disturbed at everything seeming to be too perfect and eventually figures it out. The optimum solution is the top dialogue options, which tell Feynriel about the glitches in the matrix while still letting Feynriel figure out the nature of the matrix on his own; this will make Feynriel more confident in himself and his powers. Hawke can help Feynriel break the Pride Demon's illusion by pointing out that Keeper Marethari is not behaving like Feynriel knows she behaves in real life; Marethari hates demons and would never rely on a boy consorting with demons, benevolent or otherwise, any more than she would rely on the Circle. The Desire Demon's illusion is broken if Hawke convinces Feynriel to question the following: if Vincento loved Feynriel, why can't Feynriel remember him, why did he spend his childhood waiting for him, and why didn't Vincento respond to any of mother's letters?
- Neo Quest II has odd, mechanical panels that appear at random in the first stage. It hints that this otherwise normal RPG is not all as it seems at first. The sword-and-sorcery setting is a leisure simulation on a space shuttle, and the whole party was made up of the astronauts.
- Kingdom Hearts II has Butt Monkey Vivi inexplicably take a level in badass, hinting toward the fact that Roxas' Twilight Town is really a simulation made of data.
- Kingdom Hearts coded has these as well, ranging from blocking off a doorway to making the guards in a stealth section move at several times their normal speed.
- At the end of the second Pokémon Mystery Dungeon, Darkrai traps the player in a nightmare to try and convince them to join his side. The glitch is that the player's partner completely gives up on beating Darkrai, something that by this point in the game, he or she would never do.
- dead pixels in the sky.
- Another xkcd example, in which the narrator is simulating the universe using rocks in a desert: "So if you see a mote of dust vanish from your vision in a little flash or something, I'm sorry. I must have misplaced a rock, sometime in the last few billions and billions of millenia."
- In a XXXenophile story, Orgasm Lass realises she is trapped in a virtual reality because the AI only has enough processing power to animate one person at a time. Whenever she is 'interacting' with one of the two villains in the scene, the other is frozen.
- There's an episode of Batman: The Animated Series that had the Mad Hatter trap Batman in a Lotus Eater Machine/dream. The way he realized he was dreaming was that the newspaper he was reading was gibberish. Then he remembered that the brain hemisphere used for dreaming was not the one used for reading. While that's nonsense (both hemispheres are used for dreaming, and he got it the wrong way around about which is used for reading), it is true that dreams typically fail to produce readable text—see the example under Real Life below.
- Codename: Kids Next Door has Numbuh 1 catch on in one episode because Numbuh 4 is at a pool party, in the water, swimming with everyone else, when in reality he can't swim.
- Justice League had the team realize they were in some sort of illusion, and not a timewarp. A lot of little details to the seemingly 1950's town didn't add up. None of the books had words, all the subways were boarded up, and the newspapers reported things that hadn't happened.
- In "Paradise Lost", though Lotus Eater Machine was more of an illusion causing MacGuffin. Superman and Wonder Woman are magicked into seeing each other as a monster. Eventually during the fight which ensues, Superman discovers Wonder Woman is the monster via her reflection in water. He tries to inform Wonder Woman, but she continues to attack, until he points to his reflection in a mirror.
- And then there was For the Man Who Has Everything where Superman slowly comes to realize that his idyllic life on Krypton with his son Van-El is false, in a moment that will tear your heart out.
- Invoked in American Dad when Hayley and Klaus were acting bizarre to convince Steve that he's dreaming, as a prank.
- What's New, Scooby-Doo? has the episode "E-Scream" where the gang is getting attacked by robotic furry creatures. However, during the whole fiasco, Velma notices her friends doing things that they wouldn't normally do (Fred telling the gang to stay together, Daphne wearing mismatched shoes, etc). Near the end, she figures out she's in a holographic video game made by a friend of hers when Shaggy doesn't spout his Catch Phrase right.
- This is one way to become aware that you're dreaming (lucid dreaming). You learn to notice various details in your dreams that are out of place: common traits are watches or newspapers reading gibberish or changing every time you look at it. One of the weirdest is that your hand often has the wrong number of fingers when you look at it.