Your standard Invisibility typically makes you transparent to light. While quite effective, it does have a number of catches, such as retaining the ability to be heard or otherwise detected, possibly forcing you to be an empty-handed Invisible Streaker, or even rendering you blind if it works realistically.note In short, it won't make you stealthy overnight.
The perception filter does away with these catches. This ability affects the minds of the observers, making them subconsciously look in another direction or pay no attention to the subject, or erasing the subject from short-term memory. It does have a few catches of its own, though: it obviously won't work on cameras and other objects that don't have a mind to screw with — although it's possible for the images they create to still prevent people from seeing them properly. It also tends to fail if the user draws too much attention to themselves, so the Highly-Visible Ninja and Screaming Warrior will find it useless.
Very often used by witches in fantasy, aliens in Science Fiction, and anyone else trying to pass unnoticed among muggles.
The Trope Namer is Doctor Who, more specifically a piece of circuitry of the same name, which allows the Doctor's TARDIS to blend into its surroundings, no matter what form it takes on landing. Even in its iconic anachronistic police box form, it's been stated that it can shift the perception of the person looking at the TARDIS to make them not notice it unless they actively try to.
See also: Weirdness Censor, where it's the Muggles themselves that choose to ignore it, Invisible to Normals, where it's the laws of nature that cause it, and The Nondescript, where it's something/someone so unremarkable that no one gives them a second thought. Compare Jedi Mind Trick.
- Ayakashi Triangle has a general Weirdness Censor that jinyo are able to specifically manipulate muggles to blend in. When Shadow Mei started attending school as Suzu's cousin, not only does everyone believe it, they act as if she'd been around for a long time. Hinojiki clearly looks like a child, but is able to convince people he's just a short twenty-year-old. It also seems to work unconsciously, as after Hinojiki visits and leaves the school, none of them remember he was ever there.
- In A Certain Scientific Railgun, Miho Juufuku's power Dummy Check makes people less likely to notice her. While amplified by Level Upper, it also erases their memories of having seen her.
- Eyeshield 21. One of the players for the Devil Bats, Ishimaru, is so plain that he's practically invisible, even on the field.
- In The Demon Girl Next Door, Sakura set barriers across Tama to prevent members of light and dark clans from interacting, to the point that Yuko is the only demon Momo has ever met in Tama. There are, however, some exceptions:
- These barriers are not intended to be used on muggles, to the point that they became Fantastically Indifferent towards demons.
- Yuko can interact with magical girls because Sakura's core resides in her, making her kind-of-sort-of one as well.
- The villain of the sixth The Garden of Sinners movie, God's Word, is able to use the Language of Magic to plant perfect suggestions into people's heads, such as "you will lose track of me", which makes it impossible to locate him for anyone who hears it even if he stands right next to them. This way, he becomes the only bad guy in the series to face Shiki and escape unharmed.
- In Ghost in the Shell's cyberpunk future, most people have cybernetic eye-implants, which allows sufficiently skilled hackers to essentially edit themselves out of people's vision. This trick is used in Ghost in the Shell: Stand Alone Complex by the Laughing Man, who specifically hides his face by throwing his personal logo over all images of it. The Major imitates this when she's impersonating him.
- Meleoron in Hunter × Hunter has the ability which allows him and anyone he's touching to hide their presence. They can't be sensed by sight, sound, smell, or even TOUCH.
- The protagonist of Kuroko's Basketball often goes unnoticed even off-court. With this and his misdirection skills combined, he plays a central role in the team by stealing the ball and shifting the trajectories of passes to suit his team without being noticed by the opponents.
- Dragons in Miss Kobayashi's Dragon Maid can learn this ability, known as perception blocking, which hides them in all ways except touch from all around them. Most don't because those that do are seen as wimps. All the main dragon characters do know it, though, save for Kanna and Ilulu who never got the opportunity before Tohru decided to teach them. They also use it a lot, and for a variety of reasons, ranging from going down the Japanese coast for ice cream (Elma) to observing Kobayashi at work (Tohru and Kanna, with Tohru's help) to hiding Elma carrying a car down the road (Lucoa).
- In Negima! Magister Negi Magi, the power of Natsumi Murakami's Pactio artifact is to eliminate the user and whoever they are in physical contact with from the perception of everyone else. The effect is apparently absolute, as even the Magic World arc's Dragon-in-Chief with a Reality Warping magical device was unable to see through it.
- This is how Ayakashi and gods remain Invisible to Normals in Noragami. They're not invisible per se so much as very difficult for most people to ever notice unless they deliberately attract their attention.
- In Saki, 'star player' of Tsuruga Academy, Touyoko Momoko, has a special ability to 'disappear' by blending into the background. Depending on how attentive her opponents are, it may take her a while to disappear, but once she does, the rest of the players at the table simply ignore her, as well as her discarded tiles - allowing her to pull off some truly insidious gambits. It doesn't work on Nodoka once she's in the zone - she's just seeing the entire table like a PC-monitor, and there's no room for tricks like that in Online Mahjong.
- People notice Kagero Usui from Sayonara, Zetsubou-Sensei only when his balding head is exposed. The reason is never explained.
- In Yamada-kun and the Seven Witches, there is an invisibility power, but since all the witch powers are Psychic Powers, it doesn't actually turn the user invisible. Instead, it messes with the victim's brain so they perceive the user as invisible and intangible. Those who haven't been affected by the power can still see the user.
- Yurei Deco: Deco, devices that allow for Augmented Reality interface, are mandatory. Skilled hackers like Hack turn invisible using programs that hack onlookers.
- In an Archie Comics story, Jughead justifies his drab, downbeat style of dress to Veronica by showing her that it renders him de facto invisible to teachers, canvassers for charity, and such, in contrast to her bold, stylish fashions. At the end of the story, an impressed Veronica likewise starts dressing not to be seen.
- In The Ballad of Halo Jones, Glyph had their sex changed so often they ended up with a gender-neutral body and this ability. While they find it much easier to get whatever they want (being able to bypass a checkout counter and so on), they are very lonely since they can't turn off this 'power'.
- In the first installment of The Bojeffries Saga, a council worker knocking on the family's door to demand a century's worth of rent arrears is blamed on the "curiosity damper" breaking down.
- An issue of Captain America (Tales of Suspense #79) features a gadget created by the Red Skull which emits high-frequency soundwaves to make mooks invisible to people.
- One of the people who was the eponymous Doctor Fate for a while, Inza Nelson, would switch between her civilian identity and Doctor Fate right in front of people, and got away with it by mind-controlling everyone in the area for a split second to not notice.
- Doctor Who (Titan): "Human chameleon" John Jones initially has his powers manifest like this, which is a bit of a problem for a would-be rock star. (At his first gig, he keeps asking if the microphone is on because people literally don't notice he's on the stage.) Once he learns how to control his powers, he instead uses them to become as noticeable as possible.
- Doom Patrol: Agent "!" of the Brotherhood of Dada has the power that he "comes as no surprise", i.e., nobody finds his appearance or presence particularly unexpected or notable, so people tend to ignore him. Given that he's dressed in a suit of exclamation marks and his chest is a gilded cage with a small airplane in it, this is quite an accomplishment.
- The Inhumans: One of the many ways that Inhumans kept Attilan hidden from humans is circuitry built into the surrounding area that telepathically suggests to them to change direction and hike away from it.
- In Ashes of the Past, for some reason, there's one applied to the entirety of Team Galactic; they can operate in plain sight and no-one will see, hear or even notice anything odd is going on. Only Ash and those he has Reminded of the old timeline are immune to the effect, but considering all the new Pokémon he has, that still only amounts to around half of his team and a scant handful of his new Legendaries.
- Lyra's curse in Background Pony is a variation of this. Although others are aware of her when she is present, she is immediately forgotten in few seconds once they stop paying attention.
- The Drakengard 3 fic The Blue Scarf explains that the Intoner sisters have this, on top of the False Memories the Flower gave them in canon. When Two is reconstructed free of the Flower's influence, she muses that her old self knew about the Latin numeric mark on her forehead, but somehow had just... never felt curious about it before.
She had just taken it for granted, like breathing.
- In Calvin & Hobbes: The Series this is used several times by the MTM, including in the Series Finale to Season 5-
Jack: How did you get here?
Calvin: MTM scrambled our life signs and put up a perception filter.
Andy: And yes, he does get all his gadget ideas from lame TV shows.
- In A Discordant Note, Prince Oberyn spots two women and a baby with Prince Rhaegar and forgets about them almost immediately thanks to the use of a spell. After being introduced to them, he goggles at the fact he somehow overlooked a seven-foot-tall woman and the supposedly deceased Queen Rhaella.
- Juleka is granted this power by Hawkmoth in The Downfall Akuma.
- In Empath: The Luckiest Smurf, the Psyches under the control of the Psyche Master purposely regard Empath as just being a "prototype Psyche", despite the fact that he looks like something that they're supposed to despise a Smurf. That is, until he's finally exiled from Psychelia upon his 150th birthday, and then he's treated as an outsider.
- The Emperor uses such a power in Everqueen both to protect his parked shuttle and to ensure his conversation with Horus isn’t disturbed by outsiders.
- In Fist of the Moon, it becomes a Running Gag that the perception filter that protects the Senshi's identity doesn't work at all, though it's because the Senshi have accidentally infused the ones who can see through it with magic that nullifies the censor.
- The Gensokyo 20XX Series it seems, relies on this and Weirdness Censor (as in the case of Reimu's white hair or Chen's long nails), making this justified and hand waved, allowing them to live in some secrecy and it was shattered when someone uncovered it as stated by Amoridere:
"On the note of the non-human characteristics, well, Ran is a shapeshifter, being a kitsune, so they really wouldn't have noticed her and she also has been hiding them with hats, scarves, veils, and long dresses and Chen, being I'm not sure if she can shapeshift, had hers hidden by long dresses, and usually bandannas. On the note of Flandre, well, that's easy, with the help of treatments and spells, she TURNED human, a five-year-old with xeroderma pigmentosum, in order to escape and live in the Outside World, virtually undetected. On the note of how no one notices them outside of those factors, well, I guess that could be explained by the humans there not bothering to look, though, it would seem odd that they have a woman with a hat or veil and wears a very long dress and a little girl with long nails but I guess that is how this world works, so it is a safe assumption that things don't seem too out of place in that circumstance whereas in our world we would have thought something of it. Eventually, later on in the series, someone does notice something and it throws their lives into turmoil."
- In Harry Potter and the Artificer Legacy, one of Harry's first inventions is a "Hiding Stone" which can be placed on a door to make it less noticeable to anyone not attuned to it. However, it only dissuades the mildly curious and anyone seriously looking for the door (or the person on the other side of it) it hides will be able to see through it, as Harry explains to Tonks when she requests one for her room.
- In I Am What I Am, sufficiently powerful magic weapons create a perception filter so their wielders can carry them everywhere (including not setting off metal detectors). The only known exceptions are ones too large to carry around, which instead take on more convenient forms, such as Jonathan's staff becoming a cane or Cordelia's sword becoming a tattoo.
- Lulu's Bizarre Rebellion: Inverted. Monica Krushevsky’s Geass makes opponents unable to perceive anyone except the user, which also extends to any Knightmares being piloted. This is used to make opponents unwittingly crash into each other or allow allies to escape. Fittingly, the Geass is named Just Monica.
- Allirea's witchcraft in Luminosity primarily takes the form of becoming an Unusually Uninteresting Sight, a power that affects only those open to mental control. It doesn't work on Bella, whose mind is shielded, or Demetri, who is obsessed with Allirea and therefore can't be persuaded that she is unimportant. However, on everyone else, it is extremely potent, to the point where they will shrug off even having her teeth sunk into them.
I peered at him. He looked like he was in pain, but I hadn't hurt him, he hadn't touched the door, I would have heard if he'd hit himself against the stone of the cell... I supposed he could have had a heart attack, but that didn't seem likely in someone his age. The drops of his blood perfuming the air didn't have any scent of disease on them. It was peculiar, really. The only thing that had happened to him since he'd started his description of Heidi was that the stranger in the cell had sunk her teeth into his neck and started sucking his blood.
"What's wrong?" I finally thought to ask, but he seemed as confused as I and just gestured jerkily at his throat. A few seconds passed, and he stopped screaming. I touched his wrist and checked his pulse. He was definitely dead. Maybe he'd had a heart attack after all.
- Imp explains to Adora that this is part of his power set in The Locket Of Love. It's the reason he can do things like manifest his face on the objects he turns into without anyone noticing.
- In Make a Wish the slightly seer-ish shopkeeper who sold Harry some travel equipment included a bracelet which was supposed to generate an SEP field which would render him unnoticeable unless he did something strange or aggressive. Since he never read the manual, it was kept on the lowest-power setting, which meant that people noticed him but were unable to recognize his features.
- In No Charm Equal, mortals can see Harry, but they don't really process his presence, and he just seems extremely boring and uninteresting to them. The only exception to this is Eggsy, who can see Harry and views him as a regular person. This is because Harry and Eggsy are supposed to be together, and the perception filter blocking people from really acknowledging Harry goes away after he becomes a mortal again.
- Something like this was used by the Dementors in The Parselmouth of Gryffindor to hide their ship. (It wasn't enough to fool Mad-Eye Moody, however.)
- Queen of All Oni:
- The Lost Cathedral of Cortez, which was built to seal the entrance to the Vault of Endless Night, cannot be seen unless you are standing on the lot of ground it occupies.
- Blankman seems to have something like this, as any attempts to photograph him will fail, one way or another.
- This is brought up in the Quiververse as part of a Doctor Who crossover. A large group of ponies descended from transformed Time Lord refugees use an innate version of this to escape notice and obscure their cutie marks. It breaks down, however, when a minimum of three are together in close quarters.
- In Slayers Trilogy, Luna Inverse kept Ceifeed hidden in her workplace's basement for years by casting a "Do not look at or pay any attention to the giant metal doors guarding a humongous divine dragon" spell.
- In Symbiosis:
- Pocket Watch, a hypno, puts a light mental suggestion on people to not to look at Ash to closely when he went to school.
- Sabrina put a mental suggestion on herself to not notice Captain Torch so he could get help before she went on her rampage.
- This is part of the powerset received by the main character and eventually several others in The Warcrafter, making him a blindspot to some of the more dangerous villains in the setting. After utterly trouncing one of them, he outright compares his situation to the Silence. He's managed to make devices that replicate the effect within a small area and has been actively distributing them.
- In The Witch of the Everfree, one of Sunset's stealth aids at the Summer Sun Celebration is a Background Pony spell, which makes her and her surroundings appear utterly uninteresting to any observers.
- With This Ring: John Constantine uses a spell that makes people's eyes slide right past him without noticing him. Unfortunately for John, Batman noticed that he couldn't seem to look at a particular part of the room, and punched that direction just in case, giving John a black eye.
- The Red Lectroids in The Adventures of Buckaroo Banzai Across the 8th Dimension don't wear disguises to look human, they simply use a hypnosis device to be perceived as human.
- In Bram Stoker's Dracula, Dracula is having his way with Lucy and as Mina comes down, he murmurs, "No. Do not see me." And she doesn't.
- In Invisible Avenger, the Shadow uses his psychic powers to cause others to be unable to see him. His shadow remains visible.
- The aliens in They Live! have placed one over the entire planet, using it to disguise themselves as humans and lull humanity into a consumerist stupor through subliminal messages. Wearing special sunglasses, however, allows the protagonist to see through it all. At the end, he shuts down the filter and exposes the aliens to the world, at the cost of his own life.
- Thor: When Loki visits his brother on Midgard, the humans can't see him. He also blocks himself (and Laufey) from Heimdall's Super Senses, i.e. extraordinarily acute sight and hearing that allow Heimdall to see and hear across large distances.
- Stardust: Ditchwater Sal serves Lamia a meal of limbus grass, prompting Lamia to divulge her plans to find the Star that just fell, kill her, and cut out her heart to restore youth and beauty to her and her sisters. When Lamia realizes what Sal has done, she angrily casts a spell on her that renders her unable to see, touch, smell, or hear the Star. Later in the movie, when Yvaine (aforementioned star) and Tristan approach Sal for passage to the Wall, she not only cannot perceive Yvaine, she can't even be touched by the star-turned-human when she tries to attack Sal for turning Tristan into a rodent.
- X-Men: Apocalypse: Jean Grey does this to soldiers who check the ruins of Xavier's School for Gifted Youngsters to avoid capture, and later when she and her friends infiltrate a secret military base. Of course, it doesn't work so well when a guard surprises you from behind...
- David Eddings:
- The same is used briefly in the Belgariad, to make Garion's giant sword a bit less conspicuous. In the Malloreon, one is applied to a book of prophecy to keep unauthorized people from reading a certain passage. All the passages are clearly written and intact in every copy of the prophecies, simply written on an area of parchment the size of one letter.
- The young boy and insanely clever budding thief Gher in The Redemption of Althalus, who can "dodge" telepathic powers such as those from one of the companions, Leitha. As he describes it, he can tell where a telepath is aiming his or her mental "ears" and just "steps out of the way".
- In the Sparhawk series of books, there are several different approaches to invisibility. The one most frequently seen, used by the Child-Goddess Aphrael (also known as 'The Nimble Goddess' or 'That damn sneaky thief that you just can't hate even though she just robbed you blind 'cuz her smile is so cute'), is basically this - she magically diverts people's attention, so they sorta' know you're there, but they don't pay attention to you. They'll even step out of the way to let you past, without noticing that they're doing it.
- Mikhail Akhmanov's Arrivals from the Dark: In Retaliation, Klaus Siebel (actually, a shapeshifting alien) uses a Lo'ona Aeo device to put a Human Alien under a hypnotic trance. When his human friend Paul asks why he can't see the device, Klaus explains that he's using his Psychic Powers to selectively block Paul's vision to exclude the device. Otherwise, he'd be in a trance as well.
- The wizard Visak used this to hide his treasure in Below. It's already deep in the ruins where most people would have a great deal of trouble reaching it alive, but his overlook spell ensures they'll never find it even if they blunder right into it. He also had many years to reinforce his spell with new layers of deception.
- The aliens from Peter Watts' Blindsight use a hard sci-fi version. They detect the saccadic flickering of human eyes and only move in-between the flickers. On the one hand, it only works on a single observer. On the other hand, it is extremely effective against a single observer.
- Chrysalis (RinoZ): The ants of Operation Silent Shield develop a special stealth organ that causes everyone to ignore them. Anthony is able to sense them via the Collective Will Vestibule, but when using his normal senses, even touching them goes unnoticed.
Idly, I bump up against the wall and even though I don't actually reach the heated surface my brain doesn't seem to register it.
- Circleverse, The Circle Opens: The first book of the quartet, Magic Steps, introduces "unmagic". Among other things, it can be used to make people invisible and unnoticeable even though the cloaked individuals are committing murders right in front of an observer. This is exactly how the villains are using it, by the way. The major downside to unmagic, however, is that it also has a nasty habit of consuming people it touches.
- Magic-users in Diana Wynne Jones' Deep Secret can put "don't-notice" workings on objects, though it works only as a weak Weirdness Censor.
- Trained witches and Susan Sto Helit can "fade into the foreground". This seems to be a theme in Discworld: Pratchett maintains that if something is utterly outlandish and impossible enough (for example, a donkey standing on top of a very very high pole), humans will go out of their way to not notice it or subconsciously pretend it doesn't exist. Animals, who do not have the advanced mental perception filters humans have that enable them to see exactly what isn't there and not see what is, do not fall under the blanket of this trope.
- Death himself uses it to go unnoticed, though it may be a case of outright Weirdness Censor. An interesting effect in Mort is that crowds which unconsciously part to let Death through close right up again on his apprentice; they do know Mort is there, they just don't care.
- Even though been explained like it's based on a Weirdness Censor, this is still a special ability or property that can be turned on or off, or had or not had by the same being in the same kind of circumstances. So, for example, Susan can choose to become invisible this way, and Death can choose to be visible in his true form even to Muggles. In Thief of Time, there's a scene where a clear distinction is made between Perception Filter and Weirdness Censor: Susan doesn't have to turn on her invisibility, as it were, because, as a Gothically dressed young lady walking a horse inside where she is, she really is too incredible for anyone to register.
- In Mort, Princess Keli effectively becomes invisible to everyone by accident because according to fate, she's supposed to be dead. People's brains keep telling them she's not there, she can only get them to notice her with difficulty, and they tend to forget her right away. Defied: she hires a wizard who can see her to remind people of her, and they post posters with her face and have her name shouted everywhere.
- While still a student, Lord Vetinari practiced standing so still that no one saw him. It worked.
- Early in The Dragon Knight series, Jim magically invokes this several times as an economic substitute for true invisibility.
- In Barbara Hambly's Dragonsbane, Jenny Waynest attempts to use one of these to sneak past a group of bandits, but Gareth — not realizing the situation — disrupts the spell.
- Also applies in several of her other series. Stranger at the Wedding has a scene where the limitations of such spells are explained: it's easy to appear as a servant to a nobleman who wouldn't pay attention to a servant but would fail if the noble was thinking of seducing a maid, and the butler in charge of the servants would also be paying too much attention to fool. The wizard uses spells like "Look Over There", "Ignore Me" and "This Isn't A Door" when trying to sneak around. Likewise in the Ladies of Mandragyn, an untrained wizard stops soldiers from looking his way but is caught when the gate guards use a mirror to search for him.
- The Dresden Files:
- In Fool Moon, protagonist Harry Dresden attempts to create a potion of invisibility. It's quite possible for him to become truly invisible with such a potion, but it won't hide him from the other senses of the giant super werewolf he thinks he's going to run into. Instead, he cheats by using the effects of this trope. The potion causes those around him to avoid paying any real attention to him and act as though he were so mundane as to be not noticeable—in this case, a janitor. This actually turns out to be a problem when he wants to get an Innocent Bystander's attention to warn them about the rampaging werewolf, but the potion's effects make it so that the bystander hears his yelling as meaningless small talk.
- One of Gard's valkyrie-magic runes is "Routine". While not good enough to hide something unusual from sight, when Harry casts an illusion to make himself, Gard, and Mouse look like malks in the short story "Heorot", the rune causes a pack of real malks to see the three as "just a normal part of their day."
- In The Eyes of The Dragon, the narrative helpfully explains that true invisibility is nearly impossible, very dangerous, and almost never worth the effort when it's so much easier for a nefarious magic-user to become "dim", which causes anyone that's not intimately related to the character to ignore them as if they weren't there at all.
- Father Brown:
- Invoked in one story. Nobody takes this explanation seriously.
- Another variant, fully realistic and closer to Hidden in Plain Sight, appears in an aptly-named "Invisible Man".
- In Forging Hephaestus, magical amulets used by some villains keep most people from noticing or remembering them. The vast majority just sort of skip over the spot where the person with an amulet is. Some with stronger will might squint in that direction for a second before shrugging and turning away. Only a few powerful metas, like Apollo, can see through the guise. Cameras are likewise obscured, only getting a blurred outline of a person.
- In Harry Potter and the Prisoner of Azkaban, the Knight Bus seems to work the same way as Hitchhiker's Guide's Somebody Else's Problem Field. As does The Leaky Cauldron and the door to St Mungos (when it's not disguised as an abandoned department store) and presumably most wizarding establishments. It's stated in GoF that the Wizards have spells that make Muggles remember stuff they had to do when they enter the AoE of the spell.
- Witches in His Dark Materials can do this with magic, but it isn't foolproof. Will Parry figured out how to do the mundane version of this.
- The Hitchhiker's Guide to the Galaxy Trilogy:
- The concept is parodied in the Ravenous Bugblatter Beast of Traal because you can hide from it simply by putting your towel over your head. It's an animal that is so mind-bogglingly stupid that it assumes that if you can't see it, it can't see you.
- Also introduced is the "SEP Field" of Life, the Universe and Everything, which makes things invisible very practically and effectively by causing people to believe that whatever is inside the field is Somebody Else's Problem.
- Illuminatus! gives us an interesting example in the form of the nonsense word "fnord", which is this trope to itself due to society as a whole being conditioned from an early age to immediately forget it after they've read it. However, forgetting it provokes an uneasy feeling in the reader, causing them to attribute this apparently sourceless discomfort to the actual content of whatever message the word was written in. The Illuminati strategically pepper certain documents with the word in order to force a negative reaction and dissuade people from investigating any further into what they've read. "Seeing the fnords", breaking one's mental conditioning and gaining the ability to consciously notice the word, is portrayed as something akin to the conspiracy theory version of enlightenment. This being the sort of novel that it is, "seeing the fnords" is mentioned more than a few times long before it's actually explained what fnords are.
- Imperial Radch: In Ancillary Justice, the Garseddai guns have an effect like this, though in an unusual variation it affects cameras but not biological eyes.
- The Known Space novel A Gift from Earth features a protagonist with a form of invisibility. He has a psychic power that allows him to force others not to notice him. His unconscious use of this power when he's nervous makes his social life awkward, but it is quite useful for other things. The limitations are that he has to be looking someone in the eyes for it to work, but when it happens, they will literally forget he was even there. It eventually became listed among the "officially recognized" psychic powers in the setting and was named "Plateau Eyes", based on the fact that the original novel was set on the colony world Plateau.
- Kofa Yokh's cloak in Labyrinths of Echo works on this principle. The knowledgeable characters mention that the artifact probably wasn't originally intended to be this potent, since it was created far away from the Heart of the World (which makes magical items more powerful) and would at best allow its original owner, a pirate, to dodge hits more easily.
- The Laundry Files: Dominique "Mo" O'Brien in The Delirium Brief has the ability to go unnoticed while she's investigating a party — an esoterically enhanced version of the tendency of middle-aged women to go unnoticed anyway.
- In the Lord Darcy books "invisibility" means that people just instinctively avoid looking where you are. They can still see you in a mirror, though. In one of the books a character asks "suppose they made the mirror invisible as well?" and is told they could, but you have to look somewhere, and the more places your eyes slide away from, the more likely you are to become suspicious.
- Two examples in The Lost Fleet series. Geary's team figures out the Enigma aliens don't have cloaked ships but have remotely hacked the humans' computers so their sensors ignore them. The idea is later taken up by the people who create the AI Black Fleet, who are rendered "invisible" to Alliance sensors thanks to a software update distributed to their ships. Geary points out the stupidity: the update only affects Alliance naval ships. Everyone else can see perfectly well who is attacking them.
- The Grey Men in Momo can do their work effectively because they are visible but inconspicuous. They can reconnoiter without being noticed, or persuade people into saving time without being remembered.
- The Others in Night Watch (Series) use a variety: people don't just avert their eyes, they step aside instinctively.
- They also use it for their property. That is why no Other has to worry about their car being stolen. If humans simply thought the car wasn't there, they try to park in that spot. This way, they don't perceive the car but also keep on driving. When Anton has to avoid using his powers in order to appear human, he suddenly has to be worried about leaving his car in a "bad neighborhood".
- Vampires (one of the weakest Other groups) experience Glamour Failure if a human looks in a mirror. The vampire would be visible in the mirror but not in direct line-of-sight. It is unknown if it's the same for other groups.
- The novel Nobody by Jennifer Lynn Barnes combines this with Invisible to Normals. The eponymous "Nobodies" are humans who have the supernatural ability to be completely unnoticeable and unmemorable. Most people don't see them, even when they're standing two feet away, and those who do have, at best, fleeting recollection of them. (For example, the main character laments that she has several yearbooks filled with generic greetings like "Have a great summer" because she's made no lasting impression on anyone.) However, Nobodies can see each other and there are also gifted humans called Sensors who can detect them with one of their five senses.
- In the October Daye series, the faerie have a spell that Toby refers to as a "Don't Look Here". It's good enough that people driving cars avoid the user without ever realizing the spellcaster is there.
- In Pact and its spinoff Pale, magical practitioners have the ability to see connections between people and objects that denote the relationships between them. The simplest and most straightforward form of magic is applying power to cut a connection, which has this effect-people fail to notice the person or object they were tied too, or forget what they were talking about. Advanced manipulation of connections falls under the schools of enchantment and illusion, the use of which is suggested to be a major contributor to the existence of the Masquerade which has people unaware of when magical disaster strikes-the location will exist on a map, but nobody will ever go there.
- In Please Don't Tell My Parents I Work for a Supervillain, Magenta has a particularly inconvenient version as people notice her presence just fine, but anyone who hasn't seen her for a matter of seconds can't identify her as someone they know. Her parents cope by simply assuming any stranger they encounter in their home must be their daughter, and she's told off in the cafeteria for stealing her own seat because her friend doesn't recognize that she's the same person, despite the pink hair. People with experience powering through mind-control or who rely on non-visual cues are better at dealing with it.
- Elizabeth Bear's The Promethean Age books have the "pass-unseen" spell, which doesn't make you invisible; it simply causes people to fail to see you.
- The Raven Tower: One god-spoken piece of snakeskin prevents people from noticing the person who holds it. Discussed when a character realizes that this is both more effective (since it affects all the senses) and more efficient (since it's just clouding mortal minds rather than precisely manipulating light) than true Invisibility.
- In Rebuild World, Alpha is only perceptible to those she wants to see her, rendering her invisible and inaudible to everyone but Akira unless she wants to serve as a distraction. She can also insert these filters on Akira's vision, granting him a degree of telescopic vision as well as what amounts to a heads-up display.
- In Rumor's Block Unimportant creates one of these by splitting his presence across multiple universes. This includes anything he's holding, like a flashlight, but it's dangerous for him to use it on other people.
- In The Saga of Recluce, this is one difference between white wizards and black mages. Black mages weave a cloak of light around themselves, causing a more mundane form of invisibility (with the caveat that they're also blinded), whereas white wizards actively stop the mind from focusing on them. "Wizards' roads" use the same trick, letting it seem as though villains like Antonin can be everywhere at once.
- Dina and her father from The Shamer Chronicles can make it so that others don't notice them.
- In So I'm a Spider, So What? Shiraori uses a spell to keep people from staring at or bothering her due to her exotic beauty. People who see her will think she has not outstanding features and will only recall "white". Repeated exposure or knowing her appearance breaks the spell.
- In Lois McMaster Bujold's fantasy novel The Spirit Ring a mage uses a spell to make some magical listening devices (tambourine-like objects made of parchment, small enough to fit in the palm of one's hand) not invisible (nor smaller, nor disguised as some other item) but merely "very hard to notice".
- Star Wars Legends: While usually a Jedi Mind Trick is utilized instead, some species can rather "hide their presence in the Force".
- The Temps short story "Nothing Special" by Brian Stableford uses it for social commentary; the main character is a British paranorm of Asian origin, and we only get told what his power is in the last sentence - the rest of the story continually describes him as being ignored, but the reader doesn't make the connection.
- In Barbara Hambly's vampire novels, starting with Those Who Hunt the Night, vampires who seem to appear and disappear are really doing this.
- Warhammer 40,000: In Horus Heresy, Corvus Corax can make himself unnoticeable to living beings, so that they completely ignore his presence even when looking right at him. While it doesn't work on electronic systems such as automatic sentries, people manning such equipment dismiss him as a sensor glitch even when they're miles away.
- In The Wheel of Time books Grey Men are people who have given their souls to the Dark One, and as a result always blend into their surroundings. They are used as assassins in public areas, quite capable of walking right up to someone and stabbing them without ever being noticed. They are quite cleverly dealt with in the textual medium by casual insertion into a descriptive passage so that the reader is likely to ignore them as well as the characters.
- The protagonist of Nnedi Okorafor's Who Fears Death uses this trick to infiltrate an enemy town. She called it "going ignorable".
- Turtle in Wings of Fire enchants a stick to make him not perceived or thought about by Darkstalker.
- In Witch Bank by Catherine Jinks, the protagonist's main magical ability for most of the book is to make people not notice her. It's connected to her low self-esteem; during the climax of the book she finds herself struggling to keep it working because her self-image has improved to the point that she now considers herself somebody worth paying attention to.
- Worm has a whole class of superpowers involving this and other ways of avoiding detection, known as "Strangers".
- When Imp's power is active, anyone nearby immediately forgets her presence and involvement in events, even if they were physically touching her.
- The villain Nice Guy has a lesser version where he makes people perceive him as a friendly harmless bystander, someone to be politely dismissed and then summarily ignored. However, it only works on people he's aware of; Revel identifies him from surveillance, and the aforementioned Imp quickly recognizes him as an enemy once she activates her own power. In addition, it does nothing to protect him from people who are willing to kill harmless bystanders, whether out of cruelty or because the situation meant that all bystanders were in a bad enough situation to deserve a Mercy Kill.
- An episode of Alphas has a woman named Griffin whose power is essentially this, although it is presented as traditional Invisibility. Rosen postulates that her powers operate by allowing her to hide in blind spots of those who look at her.
- Buffy the Vampire Slayer: The First Evil can pick and choose who sees and hears it.
- In Dark Angel, one man turns out to be a genetically engineered precog with a "stealth frame". People avoid eye contact with him and willfully forget that he's there.
- Doctor Who is the Trope Namer.
- Possibly the first use of the term was regarding the Chameleon Arches, Gadget Watches Time Lords can store their memories in. The watches have filters to stop the newly-created disguise personality, or anyone else, getting curious and opening them. The former Time Lord will keep the watch with them but will assume it's broken unless their attention is specifically drawn to it.
- The Doctor explains that this is why the TARDIS can go unnoticed even though it's mode-locked in its anachronistic police box form (with some help from the natural human Weirdness Censor, of course). Other examples include the pavement-stone-lift used by Torchwood's Cardiff branch (it was permanently imbued with the TARDIS's field during the rift storm in "Boom Town").
- "Aliens of London"/"World War Three" implies that this is in effect to explain why the zippers on the Slitheen's Human Disguises, which are on their foreheads, are only seen when the Slitheen wearing the disguise is actively unzipping it, even when their forehead is bare.
- It's possible to beat the perception filter with sufficient training. The Master reveals that he can detect people who are using filters. Suzie in the Torchwood episode "Everything Changes" reveals that she has trained herself to resist the "invisible lift's" perception filter. Some human organisations like Torchwood One and the Church condition their personnel against perception filters as part of their mental intrusion defense training.
- In "The Sound of Drums", the Doctor extends the effect to the TARDIS keys he and his companions carry, allowing them to avoid detection after the Master has them declared public enemies.
The Doctor: It just shifts your perception a tiny little bit. Doesn't make us invisible, just unnoticed. Oh, I know what it's like! It's like when you fancy someone and they don't even know you exist. That's what it's like.
[he rushes off to do something, leaving Martha stewing in frustration]
Jack: [to Martha] You too, huh?
- "The Time of Angels": The Doctor namedrops it as the probable reason why neither he, River, or anyone else noticed that the "statues" in a maze built by an extinct two-headed species only have one head each and are actually decayed, wingless Weeping Angels. "Low-level perception filter. Or maybe we're thick."
- In "The Vampires of Venice", the titular vampires only look human due to a complicated perception filter that combines with an actual emitter that changes their appearance to disguise their true form (though basic survival instincts prevent it hiding their teeth). The emitter scans the subject's mind to find out what they expect to perceive and then change the wearer to look like that. This is used to explain why they don't show up in mirrors — the subject's brain doesn't actually know what to fill the space with.
- "The Lodger": The rogue time machine posing as the upstairs flat of Craig's building is using one powerful enough that not only can it masquerade as the upstairs flat, it can make people think that that one-storey building has always had an upstairs.
- Used to terrifying effect with the Silence, whom you forget you encountered as soon as you are no longer looking at them. They were originally created as religious confessors, so people could confess their sins and then forget having done that, only feeling unburdened.
- "Face the Raven": Trap streets have "misdirection circuits", which render them so unnoticeable that whole communities of alien refugees can hide out in the middle of London. To find one, the Doctor flies Clara over London in the TARDIS and focuses on the bits her eyes skip over.
- "Rosa": The antagonist hides the suitcase containing his gear in an empty warehouse this way. The Doctor finds it by tracking the artron energy it gives off due to having traveled through time.
- "Spyfall": The latest incarnation of the Master, who happens to look Indian, uses one of these to make himself look white while disguised as a Nazi officer in 1943 Paris. The Doctor leaves him in a situation in part by deactivating said filter, forcing him to take The Slow Path back to the 21st century.
- "The Haunting of Villa Diodati": When the villa abruptly turns into a Mobile Maze with hallways twisting around each other to keep several groups of characters trapped in the rooms they're in, it turns out that a perception filter is involved in the process. Dr. Polidori's sleepwalking makes him immune to the filter since he's not perceiving his surroundings anyway, allowing the Doctor to figure out what's going on.
- The invisibility spray in an episode of Get Smart is described as working this way.
- In Misfits this is Simon's power. When it's active, his power goes so far as to make observers perceive doors as remaining closed when he opens them.
- Person of Interest: In the season 3 finale, Root reveals that the Machine's plan has not been to defeat Samaritan; Decima Technologies is simply too powerful, and the best that can be achieved is to keep Team Machine safe. Root and the Machine therefore set up a perception filter so that Samaritan ignores the new cover identities set up for the team (and a few programmer allies of Root's).
- Red Dwarf: In "M-Corp", the Jupiter Mining Corp is bought out by the titular M-Corp who install a perception filter in Dave Lister's brain. As a result, anything on board the Red Dwarf that isn't owned by M-Corp becomes invisible to him. This includes his fellow shipmates, as Cat isn't an employee and Kryten and Rimmer are, respectively, a droid and a hologram running on tech from other companies.
- Scrubs: Any woman wearing a wedding ring is completely invisible and imperceptible to J.D. He thought the girl who worked at the gift shop died when she got married. He bought flowers to send to her family from her.
- In WandaVision, neighbors of Westview don't perceive its presence anymore, or remember its existence to begin with.
Jimmy Woo: [to two police officers outside Westview] Pardon me, Sheriff. Would you mind repeating your claim about Westview to my colleague here?
Sheriff: [standing in front of a billboard reading "Welcome to Westview"] No such place.
Monica Rambeau: You're saying the town of Westview, New Jersey doesn't exist?
Sheriff: It's what I keep telling your G-man here, but he won't listen.
Monica Rambeau: I see. And, um, I'm sorry, what — what town are you from?
Jimmy Woo: Thank you, Sheriff. I'll reach out if we need any further assistance.
- The X-Files:
- A villain in the episode "Unrequited" can make a blind spot appear in the middle of people's eyes and hide in it: people can see everything around it, but don't see anything when trying to look directly at him, and their brain extrapolates the world without him.
- In the episode "Badlaa", a murderous Indian mystic is able to disguise himself as a janitor or simply appear invisible.
- The Shadow has a protagonist with the power to "cloud men's minds" so that he is not seen, and used to be a classic example.
- Dungeons & Dragons:
- AD&D: Apart from psionic invisibility, which is, obviously, a Jedi Mind Trick, regular invisibility is an illusion spell, so it affects the visual perception of the observers so they won't see the invisible target. That's why most invisibility spells are immediately ended if the subject attack anybody since that is much harder to ignore.
- In the game's third edition (and its offshoot Pathfinder), this is spelled out even more clearly — some forms of invisibility are glamers (mind-affecting tricks), while others are images (visual illusions). It's important because of the wide range of enemies, some of whom (zombies and giant ants, for example) have no mind to affect.
- Undead are among the creatures immune to standard mind-affecting magic, but in turn spells specialized against them for this purpose do exist — especially hide from undead which affects absolutely all of their mystical senses. Some other spells (such as shroud of undeath or undead mask) don't make one invisible to undead, but instead make the subjects appear as other undead rather than living beings, which generally mean they will be ignored. In both cases, actually attacking an undead will usually end the effect, as with regular invisibility.
Text of the Sidereal Charm Neighbourhood Relocation Scheme: As the character travels, the weave of Creation shifts, dragging part of the world after her. Specifically, both the general terrain and all habitations within her Essence in miles move with her. [...] The new location seems correct and reasonable to all witnesses, although they remember the previous state of affairs.
- Solar Exalted, have a stealth Charm (Easily Overlooked Presence Method) that functions like this.
- Sidereal Exalted, ever since they broke a constellation, fade extremely rapidly from human memories. They can hold conversations and even vague societal roles (such as "travelling merchant" or "wise teacher") but their identities — or any relationship they have with the person in question — are quickly forgotten once the Sidereal leaves. On the plus side, though, this also means that a lot of the crazy note shit they do goes unnoticed by the general population.
- Legend of the Five Rings has an Air Spell that does this.
- In Los Angeles 2035, one of the 40 mutant powers is "passive invisibility", classified as a PSI mutation and giving the mutant a bonus to sneak checks.
- In The Madness Dossier, one of the most common of the monstrous Anunnakku’s mind-control glyphs makes the bearer functionally invisible, or at least unremarkable, allowing inhuman monsters to walk through crowds unnoticed.
- In Mage: The Ascension, Mages can buy this ability as the background "Arcane", which means people tend to forget them right away after seeing them.
- Entertainingly, Arcane impacts basic object permanence at high levels, also impacts paperwork, and cannot be turned off. This tends to result in a fair degree of sociopathy in high-Arcane players: why rent that car when the official records showing you paid will disappear in minutes and the clerk is going to forget he rented it and call it in stolen anyway? Just steal a car in the first place.
- If you're high enough Arcane that the records disappear in minutes, it's actually still better to pay, because if they associate the memory with you then the entire car rental company will lose all record of having that car in the first place. The Gone Horribly Right level is usually one or two dots, where people can still see and remember you and things associated with or near you, but your existence fuzzes out after a few weeks. Expect your landlord to continually be accidentally re-renting your apartment and your credit cards to be declined.
- The Mind sphere can create an obfuscate-like effect, but the details differ to any such use, due to the flexibility of the spheres and foci. A technomancer could make it so it affects cameras as well, or any sort of mechanically-minded being, or it could work only on those things specifically. It is, however, advertised as much more reliable than normal invisibility, especially as it can even lightly influence people to get out of your way, without noticing you.
- Mage: The Awakening, the game's spiritual successor/sequel, has a less powerful version of the same skill, which can be suppressed.
- Pathfinder: The psychic spell "Aura of the Unremarkable" causes the caster and their allies to appear completely normal and innocuous to bystanders, no matter what they're doing — walking down the street, aiming a crossbow at the mayor, brutally beating a guard...
- In Rifts and the other Palladium game, this is extraordinarily frequent. Just like the real ninjutsu example below, ninjas in Ninjas & Superspies and Rifts have the ability to cloud the minds of others with chi as well as use numerous arts of invisibility that combine prowling and sneaking with misdirection and manipulation of human psychology. Psychics can use Invisible Haze, which is similar.
- In both Vampire: The Masquerade and Vampire: The Requiem, the vampiric power Obfuscate works this way. If the use of Obfuscate is particularly successful it can be powerful enough to actually technically work on recordings by camera and such; that is the subject has been captured on tape, but the effect from Obfuscate is strong enough to render the subject invisible to anyone trying to view said recording. But the effect won't extend to any objects the subject might interact with on the recording, meaning the recording can still easily be a Masquerade violation.
- Warhammer Fantasy Roleplay:
- Priests of the Trickster God Ranald have a spell to make themselves completely unremarkable to onlookers except for two details of the priest's choosing (such as a flamboyant hat), which are the only things they'll be able to remember about the priest afterwards.
- Shadow wizards have a spell to become so unnoticeable that people don't pay attention to their arrival, don't bother to approach or speak to them, don't remember them after they leave, and don't notice or care about the gaps in their own memories.
- Actively inducing this on themselves is the primary ability of the titular Assassins in Assassin's Creed, with the first tenet being "Hide in plain sight."
- In Brütal Legend, protagonist Eddie, a roadie, states that the goal of the roadie is to be completely unnoticed so the audience doesn't get distracted from the show. This extends to gameplay too, where the Roadie unit is classified as a stealth unit, despite being hulking dudes with massive piles of amps and equipment strapped to their backs.
Eddie: A good roadie knows to stay out of the spotlight. If he's doing his job right, you won't even know he's there. Once in a while he'll step on stage to fix a problem - to set something right. Then before you even realize he's there, what he's done, he's gone.
- Control has The Oldest House, which, as Pope puts it, doesn't like attention. As such, people simply do not realize it's there unless they're deliberately seeking it out, which is how a sprawling, many-floored, windowless concrete monolith of a building has remained unnoticed in the middle of New York City for almost sixty years. The FBC didn't build it, they discovered it, and they speculate that it's been around for centuries.
- Could fall under a real-life example too since the trick is on the player, but the Dark Souls II DLC "Crown of the Ivory King" uses this with the Retainer enemies. At first, they sit slumped against walls, completely ignoring your character as you pass. They give no souls when killed, so killing them is a waste of time. Eventually you stop noticing them entirely. That is, until halfway through the level, when they suddenly become hostile and wait for you to pass or get in fights with other enemies before getting up to stab you in the back.
- The Jedi Knight games use this as the basic effect for Force Persuade/Jedi Mind Trick (depending on which entry you're playing); you're still visible, you just "persuade" the Mooks that you're not really there. Overlaps with Jedi Mind Trick.
- The Stone Mask in The Legend of Zelda: Majora's Mask has this effect, making the player "inconspicuous as a stone." Link can't see an NPC wearing the mask without the help of the Lens of Truth. It turns out too that particularly disciplined or trained people can see past it: regular Gerudo Pirates will ignore you but the Mini Bosses will remark "That mask won't work on me, boy!" before attacking, attempting to enter their boss's room with it will make her scold her guards for not noticing you.
- Implemented for the Manager's own well being in Lobotomy Corporation. The Manager perceives everything through what is called a "Cognition Filter" which makes everything appear as cute, chibi-esque and doll like to keep the observer from going insane as the employees are horrifically slaughtered throughout the workday. This even applies to one particular abnormality that's so horrific that its perceived form to the player is just a mess of bars that say "CENSORED". Even its audio as it kills an employee is a censor bleep.
- Might and Magic VII and VIII have a spell Invisibility that, despite being called Invisibility and belonging to Air Magic school, from which you would expect some light reflection alteration sheganigans, is stated to directly affect the minds of creatures for them to no longer being able to notice your party. The 'not drawing too much attention' clause is in effect too, as it is broken if party under the spell attacks, shouts or casts magic. It also cannot be cast with creatures nearby.
- Minotaur Hotel:
- Mythicals have charms that make them appear human towards other humans. Even if a human were to touch a mythical's non-human part, such as their tail, they would still perceive them as human as they wouldn't even notice that they're touching a tail. That said, most charms aren't perfect, and other mythical are occasionally able to see defects in other mythicals' charms, though most humans aren't able to notice.
- The hotel automatically translates everyone's words into languages other people can understand. For example, a person who only understands English will be able to understand someone speaking Japanese while their words will sound Japanese to that other person. This extends to books and documents, but not towards modern inventions such as electronic tablets.
- The hotel also makes it so that any guests won't immediately freak out upon seeing a tall minotaur, or a large demon.
- In Pillars of Eternity, the Grieving Mother uses her Cipher abilities to make others see her as a random peasant beneath notice. However, the Watcher is able to break her filter through their soul-seeing powers. Not even the other companions notice her; asking Hiravias about her will cause him to wonder why some random woman is following you around.
- Her filter also sets off some of the most hilarious moments in the game. Most prominently and (darkly) is an event in Skaen, the God of Evil's Temple, where if the Player Character's Cruel reputation is high enough, the pool of blood will offer you to sacrifice one of your companion for a permanent status bonus. Normally, accepting the pool's offer will cause the other companions to react in horror to the sudden death of one of their comrades (but they won't know that the Watcher is responsible). If Grieving Mother is chosen as the sacrifice, however... No one cares. They don't even know she is there because of her glamour. Doing so will earn you some rather funny reactions from the others, including Durance scratching his buttock with his staff and Edér saying out loud that he is going to eat roasted chicken at the inn, while Grieving Mother is choking in her own blood.
- Remember Me: Since everyone is interconnected via their Sensen neural implants, invisibility is achieved by hacking someone's implant and forcing them to simply not perceive you. Stalker Leapers do this when not in direct light, and your Sensen Camo special will "blind" all enemies in the vicinity, allowing you to sneak behind one for a free kill.
- Resident Evil: Revelations 2 has Glasps, horrible wasp-like men who are only visible upon death or if you throw a smoke grenade (or if you have the psychic girl Natalia with you, she can see their aura). Based on how the screen gets wavy and distorted the closer they approach (and how Barry knocks himself in the head as if he's getting dizzy) it seems the Glasps are not truly invisible so much as emitting a chemical that blurs your vision and gives you a mental blind spot where they are.
- In Second Sight the "charm" ability works by making the people around you not consider you a threat. This also means it can be used to calm down allies (useful when escorting a psychotic and drugged Jayne) but it won't work on machines (like security cameras and metal detectors) and attempting to use it when a hostile NPC can see you causes their anger to burn out your power. From a programming point of view, it also allows the developers to leave the NPCs' reaction animations unchanged (enemies just act like friendly NPCs when you walk past them).
- Koishi Komeiji of Touhou Project has the power to manipulate the subconscious mind. A few passive effects of this power is that she cannot be perceived by others unless she's practically standing right in their faces and also cannot be remembered once she moves out of a person's field of vision. These powers do not affect children, who can perceive, play with and remember her until they grow up, at which point she fades from their memory as well.
- In Warcraft, the mage unit's spell Invisibility is described as granting "the ability to cloud the perceptions of others so that they cannot perceive the physical existence of the caster's target."
- The aliens in X-COM: UFO Defense and Terror from the Deep are able to locate underground bases by detecting brain waves (UFO) and using Molecular Control-based sensors (TFTD). The Mind Shield/M.C. Generator facilities can prevent UFOs from finding a base by jamming their sensors.
- Xenoblade Chronicles 3: It's implied that the inhabitants of Aionios are all under this from birth. The two armies are born from People Jars and spend their very short lifespan only warring and doing war-adjacent tasks. The characters seem to have no perception of gender as it is only after they stop being under the effect of the Flame Clock that they start feeling shame at being seen naked by other people, especially the opposite sex. They also don't realize the physical differences between each other, like Sena's glowing power lines in her skin and Lanz's metalic skin.
- One character in Zeno Clash uses a very creative variety of this trope: he wants to be invisible. Being invisible means there's nobody who can see him... so he tears out the eyes of every living creature he finds.
- RWBY has two known users of a semblance that falls under this trope:
- Lie Ren's semblance masks the negative emotions of the person it affects, making them virtually invisible against the Grimm who identify living beings through their emotions. Against humans and faunus though, it doesn't work.
- Emerald Sustrai's semblance can make anyone hallucinate by altering the sensory information the target's brain processes. While she's fine using it against individual targets, making multiple targets hallucinate seems to drain her much faster, with two people causing a headache, and an entire group of about ten causing her to faint from mental exhaustion.
- Anyone employed by the titular Awful Hospital is unable to hear, see, or comprehend almost anything involving The Parliament of the Old Flesh. One character describes what they did as messing with the Hospital's ability to prioritize important information.
- In El Goonish Shive, Immortals conceal themselves via magic when not intentionally manifesting themselves to humans and/or other Immortals. Pandora notes in the Question Mark arc that each immortal creates their own, making it so that multiple Immortals can all be observing the same event and still be unaware of each other's presence.
- In Freefall, Florence visits a restaurant run by ninja-waiters. At one point in the kitchen, one ninja calls for a distraction at a table and a man, dressed rather normally, heads out to provide the distraction. After another comments about how that man looked nothing like a ninja, the cook sagely points out that that is precisely how a ninja should look.
- In Grrl Power, Arc-Light (the Intelligence branch of ARCHON) has Gwen, a magic-user assistant, setting up a perception field around their agents during a big superhero brawl to stay inconspicuous and unbothered. This allows them to observe and gather helpful information about the opponents, that they transmit to the agents fighting on the field.
- Jix had one arc where an Ambis used a perception filter instead of the usual Holographic Disguise. It was set to make him look like some sort of animal that the viewer thought harmless, so most everyone saw a dog, but Jix's insanity made her immune, and Atra didn't know what a dog was and saw something from their homeworld.
- In Rhapsodies Celestial presence is either ignored (unless it's pointed out) or heavily edited to the point that someone might be introduced to something called Mr. Large Hideous Bull Creature and think they are talking to a perfectly normal person.
- It's used to explain how the Celebrity Paradox can exist in "A Time To Kill" (a fancomic from Rich's ComixBlog). The Tenth Doctor tells Donna that "the combination of sounds, vowels, consonants, cadence" of the James Bond standard introduction ("Bond, James Bond") acts as an audio perception filter, meaning that Bond can introduce himself to people and they won't remember details about him, including the fact that he's the living embodiment of what should be a fictional character. Then, to demonstrate, the Doctor uses the line on Donna, and she instantly forgets everything he told her about Bond.
- In When She Was Bad, Gail and Amber have this is part of their powers. No matter how public Gail's crimes are, no matter how many witnesses see her, no one can recall her face afterwards. Even when Amber tries to directly tell the police that Gail is the culprit, her calls end up being ignored or forgotten. The same power also protects Amber's identity: when a recording is made of her flying, her face appears as The Blank.
- Wychwood: Julian has cast a spell on his house to keep Wychwood from noticing that it's occupied and maintained, and keep any passerby from taking note of the house at all. It keeps unwanted visitors away and he stops maintaining it and marks the house as a safe house with supplies for other survivors when they have to flee.
- The Protectors of the Plot Continuum Agents get this while on a mission, but only from canonical characters, and only as long as they don't actively draw attention. It's Hand Waved as the world itself subtly trying to help them save it from the Monster of the Week canon breach is).
- SCP Foundation:
- Anything with this property is labeled as antimemetic. The Foundation has a class of drugs called "mnestics" which provides protection against some Perception Filters.
- SCP-268, a hat that gives its wearer one of these. Wear it long enough, and it's permanent.
- SCP-055 is a "self-keeping secret". No one knows (or more accurately, no one remembers) how it came into Foundation possession, who devised its containment procedures and why, what it is, or even that it exists. This effect even goes so far as to apply to documentation on the SCP; many reports, photos, and videos of it exist, but as soon as you stop looking at any of them you will forget all about them. Because of this, it's The Dreaded; nobody knows what else it does, and it could be horrendously dangerous without anyone knowing. It's implied that it most likely is horrendously dangerous.
- SCP-451 is a former Foundation agent who is unable to perceive other humans, their actions, or any effort to communicate with him, leading him to believe that he's the last human on Earth.
- SCP-2256 is a species of Gentle Giant Sauropod creatures who use an anti-memetic ability to appear invisible. Not only that, any information of them gradually corrodes away, with photos turning blank and writing being censored. It turns out that this is necessary for their survival as being observed was harmful to them. When a direct photo of one was taken after a device was used to remove this filtering ability, it instantly died.
- SCP-1504, aka "Joe Schmo". No matter what he does, it will be perceived as perfectly normal. During an interview he punched the interviewer in the face, but said interviewer just took a moment to clean up the nosebleed and didn't know how he got it. He only has two other abilities: he's completely indestructible, and cause electrical systems to fail just by being near them. The Foundation only found out about the Perception Filter after he caused a massive containment breach and subsequent destruction of the site he was held out, and they still haven't found him yet.
- SCP-3933 is the song "Toxic Soul" by the 80s Hair Metal band Tyrannosaurus Flex. Once, they were the most famous band in the world, possibly even in history, but today, nobody has ever even heard of them. Why? Because anyone who hears that particular song by them not only forgets they ever existed, but can no longer percieve them at all. For example, if an affected person were to watch one of the band members pick up and carry an object from Point A to Point B, to them that object would appear to be teleporting. Since the band was so famous, pretty much the only people who haven't heard the song are Foundation personnel who deliberately didn't listen to it to avoid becoming affected.
- The gamma in Shadow Unit Season 1 Episode 7 "Overkill" had this as a superpower.
- In Tales of MU, the gnomes have this as an unconscious ability, and it tends to get stronger the more of them that are together. A gnomish professor has to remind her class she's there and is completely ignored by the administration.
- Viral By Committee: As far as we know Alex can see just fine what happens around them, but other entities have filters all over the place. The Nulls are initially cut from the nanite network by the Liminal Quarantine, the zombie nanites see through a filter that scrambles faces and textnote , the Committee is first seen through a filter making them look humanoid, and in the second chapter Alex is explicitly dreaming, which greatly distorts what they see.
- One girl in the Josie stories of the Whateley Universe has this. When she goes to the police station to turn in a criminal, the police keep not noticing her, to the point that she finally has to dictate her account on a tape recorder and leave it with a note saying "play me".
- This is one of the Slender Man's powers. Unless he's targeting them directly, people don't notice him at all. If they happen to have a camera with them, they will promptly shit bricks when they watch the footage.
- Downplayed in Miraculous Ladybug. Miraculous users are protected by a "quantum masking field" that does not prevent them from being noticed entirely, but does alter people's perception just enough to stop them from drawing a connection between the heroes and their secret identities, no matter how minimal the visual difference may be. This only works on humans; in the New York special the Ridiculously Human Robot Uncanny Valley catches on immediately.
- Ninjitsu. Yes, there is real-life ninjitsu. It's a martial art, and yes, it has camouflage techniques, and it actually works as a whole class of techniques for doing this, based on human psychology and perception. It boils down to blending in with the background: documented ninjitsu lessons even cover such things as how to hide in the middle of an open field (it involves crouching into a non-human shape, so someone at a distance will just see a blob and think it's a bale of hay or whatever). Note also that ninjas didn't wear black pajamas and sneak around all the time. They mostly hid in plain sight by costuming as common farmers and villagers, who wouldn't seem out of the ordinary or suspicious.
The association of ninjas with the black pajamas is as an Exploited meta-example that's Older Than Steam: in several forms of traditional Japanese theater, stagehands and puppeteers wore body-covering black outfits to manipulate scenery and props without distracting the audience from the action on-stage. At some point, a theater troupe noticed their audiences habitually ignored the black-clad objects creeping around on stage, and came up with a brilliant way for a ninja to seemingly appear from nowhere and scare the wits out of their audience: have the seemingly plot-irrelevant stagehand reveal himself to be a ninja all along. (It's also the reason behind the Flung Clothing quick change used by ninjas — the actors' stagehand outfits would have to be breakaway outfits with their characters' costumes underneath.) While audiences eventually grew wise to the trope, the link between black outfits and ninjas became cemented in Japanese culture as the default form of Visible Invisibility for ninjas in artwork and stories, a depiction that stuck as they were introduced to the rest of the world.
- Spies are trained that way to sneak around, avoiding being chased, et cetera, often by means of being The Nondescript. Similarly, it's a part of "social engineering". Act like you belong there, maybe wear some kind of simple disguise matching what people expect others to wear, and no one will notice or question you. Is that person really someone that works in your building that forgot his keycard? Did you pay attention to the pizza guy you let into your apartment building when you were leaving?
- When little children play hide-and-seek, often a child will close his eyes, and think that nobody will notice him. When a child's mind hasn't developed yet, they think that if they don't possess a piece of knowledge, nobody else does.
- Peekaboo is based on the fact that children (below a certain age) do not know that something can exist without them observing it.
- Knowing that things exist even if you can't observe it is called object permanence — maybe perception filters override this logic. It is something that all children learn at a young age.
- Some children instead do this so they might more precisely hear anyone looking for them and thus can avoid being spotted off-guard, particularly if they are in a hiding place where their vision is limited anyway.
- Stage magicians, clowns, fortunetellers, and similar performers are actually trained to do exactly this. It again boils down to tricks on human psychology really.
- In this video, your objective is to count the number of times the basketball players in white pass the ball to each other. After you're finished counting...
- Derren Brown played this trick on a film student in this video. All he does is speak a bunch of nonsense, then add "You just simply don't see me." Then he intentionally plays out a scene from the 1933 The Invisible Man film. The camera focuses on the student's face a lot, and you can see how his vision is deliberately unfocused, as if he can't help it, and how freaked out he is when Derren picks up a doll, as if the doll is moving on its own.
- Snipers use what is called a ghillie suit, which is essentially random scraps of cloth and burlap, often augmented with local leaves and twigs. It breaks up the lines of the human body, making it extremely difficult to see them. Though meant as a long-range disguise, snipers have reported patrols and guards (even ones actively looking for them) that walked right past them, sometimes so close they were almost stepped on. A documentary on sniper training demonstrated this when it focused on a small, grassy clearing in the forest... and then the graduates in the course stood up. The clearing was essentially wall-to-wall snipers.
- Social Engineering sometimes relies on this. Remain inconspicuous, look and act like you belong somewhere, and don't say or do anything memorable or attention-grabbing, and anyone who does notice you will forget they ever saw you minutes later. How often do you remember the barista who served you the other day, the janitor you walked past, or the guy who stood in line with you?