History Sandbox / SharedMassHallucinationWickCheck

# VideoGame.ProfessorLaytonAndTheDiabolicalBox: It's the explanation for the entire second half of the game. The game uses the "expectations" justification by having photos of the town set up at the train station. Since all the main characters get to the town by way of the train, they all see the photos so they all see the same thing. Presumably, any varying details aren't worth talking about. This is also the justification for why the box is able to kill people. It has a little bit of the gas in it, so anyone who opens it expecting to die, will.
# VisualNovel.ChaosHead: One of the central ideas, but it runs on the idea in reverse: if you can get more than one person to see the same thing (real or not), it becomes real. Whether it's explained as magic or science depends on the character given the explanation, although the story focuses more on the scientific one.
# VisualNovel.{{Echo}}: Jenna is stated to believe this to be the reason behind the events that occur she's right, although while she believes it was a mundane example of the trope the reality is that genuine supernatural forces are responsible.
# Characters.GhostbustersFilmSeriesOtherHumanCharacters: He thinks that the Ghostbusters were using nerve gas to make their clients hallucinate ghosts.
# Creator.RobertSheckley: "Ghost V" has the AAA Ace team land on a deserted planet and end up fighting joint hallucinations of the monsters they invented in their childhood. It turns out, the planet's atmosphere contains a hallucinogen that forces humans to relive their childhood fears, which became really dangerous if Your Mind Makes It Real.

# Webcomic.ArtOfDomination: A few creatures are implied to be this. The Car of Destiny is the best example of it as it has no weight and can pass through solid objects.

# Film.TheCaseForChrist: Lee brings this up as a possible explanation of the Resurrection, but this is debunked by an agnostic psychology professor.
# Recap.PokemonS1E46AttackOfThePrehistoricPokemon: Officer Jenny claims this at the end of the episode to attempt to assure everyone that Aerodactyl and the other Pokemon never existed.
# VideoGame.DarkTales: When you and he witness a group of apparent specters, Dupin outright asks whether it was a shared hallucination.

# ComicBook.XFactor: How X-Factor publicly handwaved the demon attacks in Inferno. Their explanation (mass hallucination caused by A.I.M satellites) works since the existence of scientific terrorists is accepted by the average joe. The existence of demons is apparently a totally different matter.
# Recap.AmphibiaS1E06Stakeout: After drinking each other's coffee substitutes, Anne and Hop Pop end up tripping, HARD. In this case it's not a cover-up for anything supernatural - the two just hallucinate exactly the same things due to Rule of Funny.
# Literature.TheMasterAndMargarita: In the end, the authorities explain away all the supernatural events of Woland's visit as conjuring tricks and hypnotically-induced hallucinations. This includes several cases of asserting that a large group of people were induced to hallucinate the same thing together, and in the case of Likhodeyev being teleported to another city miles away, asserting that everyone who saw him the other city was likewise hypnotised somehow by a hypnotist who was in Moscow the whole time. Given how most of the demonic magic fades away over time, this works and sounds plausible enough for the Soviet people.
# ComicStrip.ModestyBlaise: In "Death of a Jester", two hippies who witnessed a man in a jester outfit being murdered by a mounted knight in armour convince themselves, even as they're describing it to Willie and Modesty, that one of their compatriots must have slipped them something hallucinogenic. Willie and Modesty decide to investigate anyway, because they know that two people wouldn't have hallucinated exactly the same thing, but they let the two hippies keep believing it so they'll get on with their lives and not get involved in whatever was really going on.

# ComicBook.AstroCity: In "The Dark Age", there is a brief mention of a battle with the L.S.Deviant, an alien that induced reality-warping hallucinations throughout the city — cars eating pedestrians, buildings breathing, people sprouting wings...
# WesternAnimation.PunchTrunk: An expert appears on TV to dismiss the tiny elephant sightings as this, but is undercut by the elephant wandering into the studio. When this short was used in Daffy Duck's Quackbusters, this was remade into a Nightline-like news segment with Daffy himself as the expert. It ends similarly, with the Ted Koppel Expy howling in laughter as Daffy is rendered a public laughingstock.
# Recap.CentralParkS2E09ABoatifulMind: Helen and Bitsy see the same eccentric sights around them as they're tripping out.
# Film.AguirreTheWrathOfGod: MindScrew: The ship in the treetops. SharedMassHallucination? Sanity Slippage? Then why do we see the ship? Are we getting mad, too? If it is real, how the hell did it get up there? And if Aguirre is right in saying that it is real, does that mean that Aguirre is sane, and the others have gone around the bend?

# Recap.SouthParkS12E3MajorBoobage: Every guy who does Cheesing seems to see the exact same Heavy Metal world.
# VideoGame.OutlastII: Wouldn't you know it, this is actually the explanation behind the entire plot of the game, thanks to Murkoff's brainwashing microwaves.
# Characters.Code7: Colburn made a scenario featuring her, causing her to occasionally appear at random for the members of Oriens station.
# Recap.WelcomeToNightValeEp7HistoryWeek: The explanation the City Council gives for the Night Vale Harbor and Waterfront Recreation Area, which definitely never happened and did not waste massive amounts of taxpayer money.
# Theatre.ShoutTheModMusical: In the uncensored version, the girls take weed and slip into the James Bond theme and Goldfinger. In the edited version, they become possessed by the souls of dead people instead.
# Film.{{Coherence}}: Played with. At one point Em raises the suspicion that Beth might have drugged the food with ketamine, which would have explained the weird occurrences. On top of her denial, the group admits that even if she had, they wouldn't all have the same hallucination.
# Characters.WeaverdiceTongju: What is actually happening during his riots.

# Film.MenInBlack: The Men in Black do this after using their neuralyzers, wipe the targets' short-term memory and make them extremely susceptible to suggestions, allowing the Men in Black to craft a plausible suggestion that everybody "saw." And since it's the targets' own brains that create false memories to fill in the blanks of whatever basic explanation the MiB provide, the usual flaw in this trope doesn't apply: each person's brain will come up with something a little different, and thus the inconsistent details from one person to the next actually make the Masquerade more believable.