Rule of Perception

If the audience can't perceive it, it doesn't exist.

The audience of a movie will know only what they can see and hear. This means that nothing really exists in a movie unless you can see or hear it (because if it does, you're going to have to explain why it was Behind the Black). As a result, a kind of accepted audio-visual shorthand has been created over many years, to help the audience understand what they're looking at and what's going on. The same is true of all other media as well: video games, theater, art, comics, written stories, and even music all have numerous ways of helping to telegraph the parts of the story that they aren't directly telling, and ways to clarify the parts that they are telling.

Tropes based on this phenomenon include:

• Acceptable Breaks from Reality
  Realism and accuracy are pointless if the audience can't understand the story.
• Acoustic License
  If the audience can hear (or see speech bubbles for) a sound, then the characters are also aware of it, physics be damned. (It can also work the other way around.)
• All-Natural Gem Polish
  Gems are naturally shiny and pre-cut so that the audience can recognize them.
• Age Is Relative
  Characters who are more competent will also look older/more mature.
• The Air Not There
  You can't see air; therefore, it does not exist.
• As You Know
  The characters already know this exposition, but the viewers don't, so it has to be stated onscreen.
• Audible Gleam
  If it just looks shiny then it could be mistaken, but if it makes the noise too then you know it's meant to be taken as shiny.
• Audible Sharpness
  It's easy to tell when a blade is sharp because it makes a "sharp noise."
• Beeping Computers
  Computers beep so that you can tell they're doing something.
• Behind the Black
  Anything that's offscreen is invisible.
• Briffits and Squeans
  Stationary images have to do something to represent motion.
• Bullet Sparks
  Bullets spark when they ricochet to make it obvious where they hit.
• Cartoon Cheese
  Cheese is always immediately recognizable by a distinctive shape and color.
• Chainsaw Good
  Chainsaws are flashy and make a lot of noise, so they must be really powerful.
• Character Tics
  You can tell he's frustrated because he's doing that thing he does when he's frustrated.
• Christianity Is Catholic
  Given that Catholic churches tend to be more ornate in design and features of Catholic services are more identifiable (eg. mass, confession), if you want to make it clear it's a church service then this is the easier kind to spot.
• Concealment Equals Cover
  If you can't be seen, you can't be hit.
• Convection Schmonvection
  Fire and lava are only dangerous if you touch them directly.
• Convulsive Seizures
  If a character has a seizure, the writers will make it the most visible kind of seizure.
• Cower Power
  You can tell a character is terrified by their exaggerated cowering.
• Culture Blind
  The audience probably doesn't know about foreign cultural norms, so the characters will be clueless as well.
• Do Not Touch the Funnel Cloud
  If you don't touch the visible part of a tornado, the most it can do is whip your hair around a little.
• Dramatic Stutter
  A clear, auditory representation of a character's shock.
• Editorial Synaesthesia
  Non-visual senses like smell and pain have to have some form of visual representation.
• Emotional Maturity Is Physical Maturity
  If the character looks physically young, they will be emotionally young as well, even if they're Older Than They Look.
• Ermine Cape Effect
  Fancy clothing is an easy way for us to tell which characters are royalty.
• Every Bullet Is a Tracer
  Bullets leave visible trails in the air to make it easy to tell which way they went.
• Exact Eavesdropping
  The person who gets to eavesdrop will almost certainly come in when something important is being talked about.
• Exact Progress Bar
  Everything has a progress bar, even if it logically shouldn't, so the viewers know how close it is to being done.
• Extreme Graphical Representation
  Computers use flashy, unnecessary graphics.
• Flash of Pain
  You can tell a video game character just got damaged because they briefly flashed a different color.
• Fluorescent Footprints
  When you're tracking someone, their trail will glow brightly so the audience can see it too.
• Frickin' Laser Beams
  Lasers behave in unusual ways that make them more visible.
• Gonk
  Particularly in animated medium, if a character is supposed to be considered ugly, then the best way to do so is to lay it on thick.
• Half-Identical Twins
  Fraternal twins need to be (nearly) identical too, or the audience won't recognize them as twins.
• He's Dead, Jim
  There will always be an obvious cue so we know the exact moment when a character dies.
• Highly Visible Ninja
  Ninjas are stealthy, but they can't be so stealthy that the audience doesn't know they're there.
• High-Speed Missile Dodge
  As long as you don't touch the rocket, you'll be okay.
• Hollywood Darkness
  It's dark, but not so dark that we can't see what's happening.
• Hologram Projection Imperfection
  Holograms have little flickers and static effects and such so that it's obvious they're not real.
• Kung-Foley
  Physical blows make loud noises so the audience knows when someone gets hit.
• Law of Cartographical Elegance
  Maps only need to show what's important to the story, so in order to prevent the audience from wondering what places might lay beyond it, no landmasses extend off the boundaries of the map.
• Laser Hallway
  A type of security system that is conveniently easy to see.
• Laser Sight
  Snipers use laser sights so that the audience can tell where they're aiming.
• Luckily, My Powers Will Protect Me
  If it's not visually obvious that your superpowers are protecting you, you'd better state it explicitly in dialogue.
• Made of Iron
  The audience can't feel the character's pain, so the character won't be incapacitated by what should be serious injuries.
• Midair Bobbing
  When a character is bobbing up and down, you know they're floating in the air and not just misaligned with the background.
• Mind-Control Eyes
  If his eyes are glazed over or spiralling, it's a good indication to the viewer that he's being brainwashed.
• Model Dissonance
  Sometimes a game's graphics must be tweaked so they look right to the player.
• Morphic Resonance
  When a character shapeshifts, there are visual cues that make it easy to tell they're the same person.
• Motive Rant
  If the writers want the audience to know the bad guy's motives, he has to actually explain them at some point.
• Narrating the Obvious
  For the benefit of the audience, having characters narrate events that should be extremely obvious to them.
• National Stereotypes
  How else will you know that it's foreign?
  • North America
  • Middle & South America
  • Africa
  • Western Europe
  • Eastern Europe
  • Asia
  • Oceania
• No Peripheral Vision
  The camera doesn't have peripheral vision, so neither do the characters.
• Not the Fall That Kills You
  As long as you don't splat into the ground, you'll be okay.
• 1-Dimensional Thinking
  Fleeing characters could avoid mishap by stepping aside rather than continue rushing forward.
• Offscreen Inertia
  As long as a character is offscreen, it's assumed that they continue doing whatever it was we last saw them doing.
• Offscreen Reality Warp
  Implausible changes are accepted if they happen offscreen.
• Offscreen Teleportation
  Offscreen characters are in a sort of limbo that allows them to reappear wherever they like when they come back onscreen.
• Outrun the Fireball
  As long as you can escape the visible blast, you won't be hurt by the invisible shockwaves that would tear you to bits in real life.
• Paper-Thin Disguise
  A character's disguise is much more transparent than it would take to obscure who they are, but if their disguise was actually that good, the audience might not recognize them, either.
• Power Echoes
  Super-powerful characters have a voice that echoes or reverbs dramatically.
• Power Floats
  Ordinary people can't float, so if a character can then he must have some sort of mystic power.
• Power Glows
  Power is represented with a highly-visible glowing effect.
• Psychic Nosebleed
  A strictly-mental injury is represented with the more-visible effect of a nosebleed.
• Puny Parachute
  Parachutes are small enough to fit on the screen.
• Radio Voice
  You can tell the voice is coming from the radio because it's slightly distorted.
• Realistic Diction Is Unrealistic
  Fictional conversations are, on a meta-level, pre-scripted, so there's no reason they can't be perfectly polished and smoothly flowing unless the plot specifically calls for it.
  • Hesitation Equals Dishonesty
    Likewise, when a character pauses for any reason, it's an audio cue that he's second-guessing what he wants (and doesn't want) to tell the others.
• Repeating so the Audience Can Hear
  We can't hear the other end of his telephone conversation, but that's okay because he'll repeat it back for us.
• Rustproof Blood
  Blood stains stay red to let the audience know that they're blood, as opposed to other things that stain brown, such as mud, chocolate or feces.
• See No Evil, Hear No Evil
  If it isn't visible, it isn't audible either.
• Soft Water
  Why shouldn't water be softer than dry land?
• Some Kind of Force Field
  A visible disruption effect in the air, usually with appropriate sound effects, accompanies a force field.
• Sounding It Out
  A character reads something out loud for the benefit of the audience, even though there's nobody else around to hear.
• Sounds of Science
  When scientific minds are engaged in scientific debate, they will mutter in a scientific manner so everyone can tell that's what they're doing.
• Space Flecks
  If you can see the stars moving out the window, you know you're moving through space.
• Space Is Noisy
  There is sound in space because the viewers want to be able to hear what's going on.
• Stock Costume Traits
  Certain visual cues let the audience instantly identify a character's profession.
• Stock Visual Metaphors
  An index of visual shorthands that help the audience understand what's going on.
• Stray Shots Strike Nothing
  The bullet missed the target, therefore it no longer exists.
• Streaming Stars
  If the stars seem to be stretching into lines as they go by, you're moving through space very quickly.
• Technicolor Toxin
  Poison is brightly-colored so it's easy to tell that it's poisonous.
• Tertiary Sexual Characteristics
  For obvious reasons, you can't just display a character's genitalia, so you've got to find some way to make it clear who's a boy and who's a girl.
• Theatrics of Pain
  Actors exaggerate pain for the benefit of the audience.
• Translation Convention
  The characters may be foreigners, but the audience has to understand what's going on, so they're speaking English (or whatever the audience's language is).
• Traveling-Pipe Bulge
  When a character is traveling through a pipe, the pipe will bulge to show their location.
• Tron Lines
  Glowing blue lines over everything are a good indicator of advanced technology.
• Viewer-Friendly Interface
  Computer interfaces are designed for the viewers watching them on TV, not the characters who are actually using them.
• Visible Invisibility
  The audience needs to be able to see what an invisible character is doing.
• Voiceover Letter
  We can't see the actual text of the letter, so instead we hear a voiceover of the person who wrote it.
• Voices Are Mental
  If characters swap bodies, their new body will talk in their old voice so that you can tell it's the same character.
• Walk-In Chime-In
  A character just entering the set has somehow heard what the characters already there were talking about before they walked in—the audience knows, after all, so the characters should too.
• Water Is Blue
  In drawn media, water is always depicted as a clean blue rather than clear. This way, it's much easier for the audience to see it.
• When It Rains, It Pours
  There's no point in having it rain so lightly that the audience can't even tell it's raining, so if it's gonna rain, it rains a lot.
• Worm Sign
  When something is tunneling underground, you can tell where it is because it will displace dirt or break floorboards on the surface.
• X-Ray Sparks
  You can tell he's being electrocuted because his skeleton is showing through his skin.

A lot of these violate Real Life physics because Reality Is Unrealistic. But Tropes Are Not Bad. Remember, this is in consideration to the audience, so if you're looking for realism, go check out naturalism, aka Slice of Life. The Rule of Perception is the whole reason Foley artists and sound mixers exist.

Related to The Coconut Effect, in that the Rule of Perception is often what causes the initial drift away from reality.

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Unsorted Examples:

Anime

• Detective Conan often has people whose actions the audience is suppose to know, but whose specific appearance is unknown to the other characters, rendered as all-black silhouettes even in places where there would be no shadows (even outdoors in the middle of the day).
• Death Note: Light Yagami's eyes turn red and glow during his most psychotic moments. Unlike other fictional characters with glowing red eyes, Light isn't magical (not that the option wasn't offered multiple times) so his eyes aren't actually glowing in-universe; it's just visual shorthand to show us how far he's gone.

Advertising

• In a feminine-hygiene ad, some blindfolded women try to identify the rhinoceros standing between them. Their guesses are all inanimate objects, based entirely on the shape of its body parts that are seen on screen ("It's a rope", "It's a pillar", etc). None of them notice that it smells like a big freakin' animal, that it's warm to the touch, or that it's moving slightly.
  • A case of Rule of Perception meets Completely Missing the Point, as in the original parable that inspired this scenario (which involves an elephant), the blind investigators know it's an elephant, and are asked what the animal is like, not what it is.

Comic Books

• Sue Storm's "invisible" self and force field are visible to the audience, by dotted outlines in the comics and Conspicuous CG Predator-like distortion in the movies.
  • Played with in both. When they want the audience to see that Sue is doing something, such as sneaking around invisibly or deploying an invisible force-field, they will be rendered visibly. When they want Sue's reveal to be a surprise, they will leave her and her force fields totally invisible until the reveal.
  • Improvement in art quality has removed the infamous dotted lines from the comics and replaced them with the same effect used for glass.
• In the Don Rosa story "The Three Caballeros Ride Again," Jose Carioca hides out in Donald Duck's trunk and asks him to help him flee from a bandit. The two exchange several lines of dialogue, but do not recognize each other until they are face to face—apparently in a comic book, neither of them can hear the other's distinctive speech patterns...
• When Jean Grey/Marvel Girl of the X-Men uses telekinesis, visible (to the reader) pink energy is often shown moving from her head to whatever she's manipulating. Other telekinetics often have similar effects (light blue for Justice/Vance Astrovik, purple for Psylocke, dotted lines or translucent white for the Invisible Woman, etc.). Rarely, if ever, is it made clear whether this energy is supposed to be visible or not. Often, onlookers will clearly be unable to tell why an object is moving seemingly under its own power, but on at least one occasion another character referred to Jean's telekinesis as "pink stuff."
  • For that matter, pretty much every mental power gets a visual representation. Examples include concentric yellow circles for Aquaman's animal control powers, lightning bolts around his head for Professor X's telepathy (rarely used anymore), a wavelike effect for Magneto's magnetic powers, squiggly lines around his head (with half of his face turning into his mask if he's in his civilian ID) for Spider-Man's spider sense, etc.
    • A strange result of this was the case of Ink, a character who thought he had the mutant ability to simulate others' powers by getting an appropriate symbol tattooed on his body (it turned out he was a normal human - it was the tattoo artist who had super powers). One of his tattoo powers was telepathy, which he got from having lightning bolts tattooed on his head, just like the ones used to show Professor X using his powers in old school X-Men comics.
• Doctor Strange's astral self is represented by a 'ghosted' version of himself with various other visual effects. Whether other characters can see him is indicated by dialogue. He also has visual indications when spellcasting, usually in the form of a glow around his hands.

Fan Fiction

• My Immortal is blissfully unaware of the Rule of Perception, as a result of which characters often seem to materialise out of nowhere.

Film

• Godzilla vs. Megaguirus: We know that large insects are noisy. One would think that Megaguirus, being a monstrous dragonfly-like insect almost as big as Godzilla, would be pretty loud. But no, turns out she is as stealthy as a ninja. Godzilla and humans alike tend to fail to detect her until she is right on top of them.
• In Willy Wonka and the Chocolate Factory (1971), none of the visitors recognize that the chocolate river is chocolate until Mr. Wonka tells them. Mr. Salt even comments "It's industrial waste, huh?" Clearly, the chocolate smells no stronger near the chocolate river than anywhere else in the confection-filled room.
  • Epic Movie has a characteristically boneheaded take on the same scenario: Edward drinks from the "chocolate river," and apparently likes it just fine, until someone tells him it's actually a sewage line.
• In Star Trek VI: The Undiscovered Country, Scotty is shown sitting alone in the conference room studying some blueprints shortly before discovering a major plot point. The blueprints consist of small-scale external views of the Enterprise. This is the sort of basic information we'd expect the chief engineer to have committed to memory. But it tells the viewer that Scotty is hard at work, better than a random electrical schematic might.
• In the 2010 version of True Grit, the speed of sound issue is noticibly averted. When Rooster Cogburn fires a rifle as a signal from across a valley, we see a plume of smoke shoot silently out of the gun, followed seconds later by the distant crack.
  • Rule of Perception is one of many tropes that The Coen Brothers make a habit of averting and subverting in most of their films.
• In Cloverfield, the eponymous monster just shows up practically on top of the protagonists in central park at the very end, yet no indication of its approach is shown beforehand, like the fact that the ground quakes when it walks, and it tends to clumsily destroy the surrounding environment wherever it goes. The creature just appears out of nowhere to the protagonists because it appears out of nowhere to the audience.
• In Self/Less, Madeline doesn't recognize the body of her husband until he turns around, despite having a good view of him from behind and hearing him speak. Granted he's wearing different clothes and was thought to be dead, but she seems to think he's a complete stranger until he turns around and she sees his face.
• In The Avengers (2012) and Avengers: Age of Ultron, No Endor Holocaust appears to be in play during the battles in Manhattan and Sokovia, respectively. Captain America: Civil War averts that trope with footage from those battles and others showing that, yes, innocent people had died during those battles and the Avengers had not noticed due to dealing with Loki's Dark World army and Ultron.

Literature

• Thursday Next retreats to a fictional world for a while in the The Well of Lost Plots, and notices several things, like wallpaper, underwear, and breakfast, are missing because they're not usually mentioned in stories. She also finds that she is one of the only people with a sense of smell.
  • And a sense of hearing, at least as we understand it. Although Bookworlders aren't deaf, they can only hear what's explicitly stated in the text. For example, they can't distinguish voices unless something like "Thursday said" appears after the quote.
• In Hush, Hush, Nora finds a gun in Patch's car, which is splattered with a red substance that she assumes is blood. Patch explains that the gun is a paintball gun and that the red substance is paint from a game a few days ago. It's possible that Nora simply can't tell the difference between a paintball gun and a real one, but the smell, texture, and color of several-days-old blood is different than several-days-old paint. (For starters, dried blood gradually darkens to black.)

Live-Action TV

• In "The Pine Bluff Variant" of The X-Files, Mulder and Scully's conversation is bugged with a laser beam against the window of Mulder's apartment. The laser is bright red (so we know it's there), instead of infrared, which would be a lot more discreet.
• Heroes:
  • When Matt Parkman reads someone's mind, the audience usually hears a jumble of sounds, with an occasional clear sentence bubbling through the chaos.
  • Parkman usually tilts his head when reading minds. Lampshaded in an episode where all powers were lost but Parkman wasn't immediately aware of it. He tried to read someone's mind, but the target simply said "why do you keep tilting your head?"
  • Many of the other powers in Heroes take this to an almost absurd degree. Peter and Ted's hands glow when they are emitting radiation. Elle's electricity is in the form of blue sparks. Sylar's lie-detection skill is indicated with a shake of the camera (and usually his saying "You're lying!" directly aferwards).
  • In the earlier seasons, Hiro's powers require intense concentration, AKA screwing his face up.
• A Law & Order episode had the detective miss a dead body directly in their line of sight until the camera could see it.
• In a CSI arson investigation, Greg must compare a used match from the crime scene to a large pile of matchbooks taken from a suspect's home. In through-the-microscope views of him holding the torn match end to the matchbooks, the used match's cardboard shaft is dark in color, while the books' matches are light. This makes it more obvious to viewers that they aren't a match for one another, but begs the question of why Greg bothered comparing those samples microscopically at all, when their colors are so visibly different.
• Doctor Who uses this combined with Rule of Scary in "Blink". The Weeping Angels cannot move if they are being looked at, which means on camera specifically. The Fourth Wall Will Not Protect You.
• How I Met Your Mother frequently uses this and it became a hallmark for the show. They constantly play with the use of narration in how the story unfolds and how the characters perceive a situation. One notable example was "Three Days of Snow" where Ted explains "This is a three day story" and we see three different plots going on simultaneously, only for a twist in that each story takes place on a different day. Another episode "No Tomorrow" has Ted believes himself to be experimenting with an unusually lucky night he was having at the bar. But Marshall shows him an accidental audio recording of Ted's evening where Ted's dialogue is the same but changed from curious and honest to sleazy.

Music

• In the music industry, if you're not in the public eye people assume you're not doing anything, or have "Fallen Off". Usually happens when an artist isn't properly promoted, or ignored by media outlets.
• Bone Thugs-n-Harmony hit this trope HARD in the 2000's, They would release mainstream albums and people would still say "I thought they broke up?", Or "I didn't know they had a new album out". Despite having previous albums people seem to have short attention spans thanks to the Fleeting Demographic Rule.
• Good luck hearing The Beatles' catalogue the same way after reading and listening to some of the examples here.

Video Games

• The Eve's Garden strip club in Bioshock probably qualifies; the sign includes the anachronism "XXX", which would not come into use in Real Life until the 1970s. But players instantly recognize the shorthand.
• Any Visual Novel with multiple routes, and the challenges facing the heroine in her route are assumed to occur regardless of whether or not the main character is involved with her. Potential Nightmare Fuel without this trope, especially if the heroine will meet a horrible fate without the intervention of the main character. Does not apply if intervention by the main character causes her suffering circumstantially or directly.
• In the Super Mario Bros. series, any pipe with a Piranha Plant will only hurt you if you can see the plant. If the Plant is currently inside the pipe, you can go inside the pipe without taking damage.
• Played With in Stick It To The Man. The hand you use to interact with the world is invisible to most characters.
• This is likely the only explanation as to why everyone keeps mistaking Shadow for Sonic in Sonic Adventure 2 despite several cameras getting close-ups of his very different face from Sonic's. The player has to know that the hedgehog going around wreaking havoc is different from Sonic.

Web Comics

• The Cartoon Chronicles Of Conroy Cat naturally toys with this one now and again. The "off panel" aspect of this trope is one that Conroy picks up on incredibly quickly during his 'toon training, to Doggy's irritation.
• In The Order of the Stick, whenever Elan plays his bard song, green musical notes fill the air. As part of the strip's general Medium Awareness, one (green) character notices that they are the same color as she is.

Web Original

• In Noob, Tenshirock's avatar seems to exist for interaction with players, NPCs and in-game objects. However, erasing it is treated as the same thing as keeping him from doing anything to the game and the effects of his hacking only seem to ever happen a short distance away from him.

Western Animation

• In the second season pilot of My Little Pony: Friendship Is Magic, Discord corrupts Twilight Sparkle's friends one by one. When the ponies turn into jerks, they also become sepia-toned and later turn gray. Spike and Pinkie Pie are the only ones to note the color change, and both characters are among the only ones to have openly broken the fourth wall before.
  • More generally, the colored auras that show up around unicorns horns or levitated objects are purely for the benefit of the audience. Some fans forget that the characters are incapable of seeing them.
• In Avatar: The Last Airbender and The Legend of Korra, Airbending can be seen as visible gusts. Given how people normally can't see air, this is done to give scenes a little extra flair. And to avoid having a character look like a dork throwing their arms around without some sort of visual to show that they are doing something.

Real Life

• In his classic essay "That Which Is Seen, and That Which Is Not Seen", the 19th century French economist Frederic Bastiat argues that many destructive government policies arise from tendency of people to only focus on what is obviously visible.
• Inverted in quantum theory, since observing a quantum phenomenon actually changes the output of the quantum effect.

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