Alice and Bob are two mischievous little kids aged around 8-14. One day, they decide they'll go to the movies. Their parents are fine with this, but warn the two of them not to see that new horror film that just came out. Alice and Bob swear they'll see an age appropriate kid film and go off to the movies innocently. Of course, they'll go see the horror film anyway, either getting in easily or sneaking in if the guy at the ticket booth won't let a pair of kids in. This backfires when they find out how terrifying and gruesome the horror movie is, and nearly end up half-traumatized. The rest of the episode will usually consist of them having nightmares and eventually being outed to the parents at seeing the film. Another common version is the kids watching it at home when the parents are out. Sometimes, though less common, the parents will be there as well.
Of course, in Real Life, a lot of children enjoy a good horror movie. At least depending on their age.
If this trope pops up in a kids' sitcom, it will almost always overlap with Can't Get Away with Nuthin' . See also Girls Are Really Scared of Horror Movies and Scare 'Em Straight. When something like this happens in Real Life, see What Do You Mean, It's Not for Kids?. It can sometimes be inverted, where adults are terrified of the film but kids love it. (See also Fridge Horror for that case; perhaps the kidsdon't understandwhy the events of the movie are something to be afraid of.)
In the first Home Alone movie, Kevin watches an old gangster movie that he was previously not allowed to see. It ends up scaring him, but he later uses the audio of that scene to ward off the burglars (as well as to scare the living daylights out of a pizza deliveryman). He watches another in the second one and the same thing happens, except he uses it to ward off the hotel staff instead.
In Ways to Live Forever, Sam and his friend Felix watch a horror movie in secret, until the parents find out and freak out. Being as the two kids are dealing with leukemia, they wanted to be able to say they've seen a horror film before they die which puts the parents in an interesting situation.
In the Diary of a Wimpy Kid book Dog Days, Greg and Rowley watch a B-Movie called Hello, You're Dead that they found in Rodrick's room, featuring a muddy hand. Rowley has his eyes covered the whole movie. Greg doesn't find the movie all that scary... until the end, when the "muddy hand" crawls straight to the screen, meaning the "hand" is coming for the viewer next.
Manny, who's already scared of ghosts, accidentally watches one of the horror movies left in a player. The result is a Nightmare Fuel Coloring Book.
Discussed in the Harry Potter spin-off, The Tales of Beedle the Bard, a collection of wizard fairy tales with commentary by Albus Dumbledore. He tells the true story of a little girl who was once ordered to go to bed, because she was too young to hear the story about to be told to her older siblings. The story, "The Warlock's Hairy Heart", was about a bitter man removing his heart so he would never fall in love, who eventually killed a woman and ripped out her heart and ate it to try and feel emotion. She was so traumatized that she rewrote and Bowdlerized all the tales into horrible mountains of glurge. She never could manage to do it to TWHH, so she just refused to print it.
The Suite Life of Zack and Cody has the twins take their dates not to see the kiddie film "Doggie Came Home", but the horror film "Zombie Mom". Zack ends up having nightmares and sleepwalking in the hotel, stacking the lobby furniture against the door to stop the zombies.
A variation happens in an episode of Lizzie McGuire where Matt gets scared watching a horror film, though it happens with his parents present. He ends up trying to Feng Sheui the house to get rid of evil spirits.
Not a horror film, but in Raising Dad, Sarah takes Emily with her and her friends to see an R-rated movie called "Love To Love". Emily ends up trying to practice making out with a boy from school. At the end of the episode, Sarah reveals that she's been lying to her dad about what movies she sees for years.
One episode of Hope & Faith has the family try to convince Hope to quit her chef job by showing themselves pretending to be completely lost without her. Justin's part?
Justin: I was up all night watching The Exorcist. I will never go to church or sleep again.
On Full House, Stephanie wouldn't eat Jell-O for a month after watching The Blob, but she demands to be allowed to watch The Wolf Man (1941) with D.J. and Kimmy. When Jesse caves in, she winds up scared by that too, and he winds up dragooned by Joey and Danny into helping her get over her alarm by playing a slacker teen wolfman in an improvised skit.
"Zoey 101" has Dustin watching a Japanese horror film with the guys against his sister's orders. He naturally gets so scared, he refuses to sleep in his own dorm room. When Zoey and her friends tire of Dustin wanting to sleep in their room every night, Zoey confronts him and he admits that he wasn't really scared after the first night and just wanted to spend more time with his sister.
In The Goldbergs episode "Mini Murray", Gramps wants to see The Great Mouse Detective, but Adam wants to see Scarface. How does he accomplush this? By tricking Gramps that Scarface is The Great Mouse Detective. Adam winds up getting scared of some things in the episode, like a clown doll, and attempts to throw it out.
Gramps: Okay, where's the mouse?
The Series/Dinosaurs episode "Monster Under the Bed" Starts out with Earl letting Baby watch a horror movie involving a mad scientist bringing vegetables to life. Naturally, the Baby spends the next few days screaming about a monster under his bed, keeping his parents up. Then it transpires that there really is something under the bed...!
Parodied on Father Ted, where amazingly thick twenty-something Dougal is warned to definitely not watch the horror movie that's coming on that night. You can probably guess what happens from then.
What makes it even better is that in an earlier episode, he gets scared out of his wits by a Goosebumps style book written by Gary Lineker.
Dougal: Whew. I'm not reading that book any more, Ted!
Possibly referenced in the opening to the Moxy Fruvous song "Splatter Splatter":
His famous "Chicken Heart" routine is this with a horror radio show (Arch Oboler's Lights Out). It culminates in him smearing Jell-O on the floor to trap the giant heart and setting the couch on fire.
Another routine involves him and a friend going to the movies and trying to watch Frankenstein, and never opening their eyes to see the monster. This leads to them staying at the theater for hours, through multiple showings, trying to build up the courage to look at the monster. Afterwards, he and his friend walk home, late at night, scared that the monster's going to jump out and get them. This leads to them running into a wino, mistaking him for the monster, and running up his front and down his back, and all the way home.
Homer takes Bart and Lisa to see a horror film about a possessed doll. All three end up terrified that there's a monster in their attic, which leads into the episode's real plot about Artie Ziff living in their attic.
"Wild Barts Can't Be Broken" has the neighborhood kids sneak out after curfew to a drive-in to watch The Bloodening (a parody of Village of the Damned).
In "O Brother, Where Bart Thou?", Bart takes the orphan Charlie to see Sever V. After Charlie is scared witless, Bart realises that having a little brother involves more responsibility than he previously thought.
Pepper Ann gets invited to a slumber party where they will be watching the R-rated film "Gutter Clowns", which Lydia warns Pepper Ann against seeing. At first, Pepper Ann tries to stop the girls at the party from watching the film, but ends up watching it anyway, and is terrified for the next few days.
The Tiny Toon Adventures episode "Duck in the Dark," where Plucky watches a marathon of "Eddie Cougar" horror movies, including one that has him attacking a screaming Bambi. It ends up giving Plucky horrible nightmares.
The VeggieTales episode "Where's God When I'm S-scared" starts with Junior Asparagus watching "Frankencelery," and becoming frightened by everything in the house after that.
Subverted on Arthur. Muffie's parents try to ban the "Scare Your Pants Off Club" books (an expy of Goosebumps) after she has nightmares from reading one. It turns out that she reads them all the time and that the nightmares were caused by her sneaking ice cream.
In an episode of The Buzz on Maggie, Maggie and Rayna sneak into a scary R-rated movie. Rayna ends up so traumatized she'd rather watch the baby movie that's playing on another screen. Maggie plays it cool at first, but eventually starts hallucinating the movie's monster everywhere until she confesses to her parents. They decide her trauma from watching the movie was punishment enough.
One episode has Johnny and Dukey, after several attempts, getting an M-rated game. They get nightmares after they play it.
Another episode had Johnny stay up late watching a horror movie marathon despite his dad telling him not to. To ensure that he wakes up on time and keep his illicit film-viewing a secret, he steals his sisters' alarm clock, which just happens to be programmed to record the sleeper's dreams and make them real.
Upon unexpectedly having to work late, The Iron Giant's Annie Hughes forbids her son Hogarth from gorging on snacks, staying up too late, or watching scary movies. So, naturally, he plunks down in front of the TV with a box of Twinkies to catch the midnight Creature Feature as soon as she's gone. And it's his paranoia over being hearing noises after being creeped out by the movie that leads him to leave the house with his flashlight, helmet, and BB gun, and discover the Giant for the first time.
One episode of the Dexter's Laboratory reboot has both Dexter and his dad sneak up after bed time to watch a late night b-movie horror flick. This results in the two of them getting increasingly freaked out when searching the dark house after the movie is over, and the next morning has both of them frozen in a catatonic state in the hallway.
Camp Lazlo: In "Movie Night", according to the Bean Scout regulations, Edward is too young to watch Mountain Zombies of Scab Lagoon (rated BB, Big Boys), and has to watch Mr. Cotton Goes to Bubbleland instead. He later locks himself in the projection room and watches Mountain Zombies of Scab Lagoon alone and scares himself silly.
Doug did this in both Nick and Disney versions of the show: In the former, Doug goes to watch a monster flick but can't get through the movie without covering his eyes when the monster reveals itself, leading to nightmares. He eventually gains the courage to finally sit through it and finds that, not only is the monster not scary looking, but the zipper on the costume is showing. In the Disney version. Doug is forbade from seeing an R-Rated Terminator like flick. He and Skeeter manage to sneak in and are horrified by the violence of it. When having dinner with the family, he daydreams their heads coming off their bodies and flying around.
Inverted in an episode of the The Fairly Oddparents, Timmy's parents won't allow him to watch a horror movie thinking this will be in effect. But it's his father whose the jumpy one through the whole episode even starting a mob upon seeing a Fly-Headed Timmy (the result of a wish Timmy made). After Timmy clears up everything, his dad allows him to watch the movie with him while still under the bravado that he isn't scared...until getting spooked by Timmy's mother coming into the room with face cream on her face. Timmy doesn't even flinch.
The Goof Troop episode "Midnight Movie Madness" dealt with Max and PJ seeing a horror film, the irony is Max gets scared and he wanted to see it and PJ ends up enjoying it even though he didn't want to see it, after Pete finds out and learns it didn't scare PJ he tells him that the movie was based on a true story and ends up scaring them for most of the night, and meanwhile Goofy gets locked out of the house during a thunderstorm and gets covered in mud and leaves and Max, PJ, and Pete think he's the killer.
In the Monsters vs. Aliens episode "Attack of the Movie Night", Sqweep sees a horror movie despite being warned not to, and gets scared by the monster in the movie. To get him over his fear, the monsters device a costume like the one in the movie to get him to face his fear. Only two things wrong with that scenario: One, Sqweep got the memory of the movie extracted, so when he sees Coverton wearing the costume, instead of being scared, starts attacking him; and two, that extracted memory comes to life, so now the movie monster is on the loose.
Rocket Power: In "Reggie: The Movie", Reggie goes to see a horror movie called "Sharkenstein's Revenge" that scares her so badly that she blows a big surfing competition the next day. In this case, her father actually gave her permission to see the movie if she thought she could handle it and, although she didn't want to see it, she was goaded into it by her friends calling her chicken.
Some children will be terrified out of their wits by some movie scenes that turn out to be scary but are in films that aren't even meant to be scary (or worse, are meant to be scary for that one isolated scene).
They don't have to watch the movies, just watching the trailer, or looking at the posters are enough to scare them. This is true for any media with horror elements such as TV Shows, video games and books.
There are many people for whom this was the way they were introduced to horror movies.
Just about any kids who are too young to understand will probably be scared by a lot of these movies while older children will be tuned in.