Kevin McAllister’s iconic scream inHome Alonealmost looked very different.

DirectorRian Johnsoncalled it “kind of … a happy accident.”

3.InHome Alone, Kevin was supposed to move his hands from his face before his iconic scream.

Jamie Lee Curtis and Ana de Armas in scenes from a movie. In the second and third panels, Ana de Armas is holding and drinking from a mug. Background includes other people

Her panicked reaction was real, and it was kept in the film.

The limp ended up adding to the realism and tension.

I flipped, because it was so stunning, it was quite amazing."

Three-panel sequence showing a person with short hair breaking a glass sculpture. In panel one, they hold the sculpture up. In panel two, it drops. In panel three, they look shocked

In the final scene, Caine doesn’t speak.

7.Daniel Craig’s suave water bottle catch inThe Girl with the Dragon Tattoohappened completely by accident.

Watch the moment in GIF form here.

Macaulay Culkin in a memorable scene from "Home Alone," with hands on his cheeks and mouth open in shock

(Sorry it’s so dark why don’t we light movies anymore???)

8.InThe Lord of the Rings:The Two Towers,Viggo Mortensenbroketwotoeswhile kicking a helmet.

His scream of anguish, followed by his fall to his knees, was real.

Kristoff, wearing a thick fur coat, interacts with Anna inside a cozy wooden cabin filled with various tools and shelves in a scene from Disney's Frozen

As this cry of pain matched Aragorn’s emotional pain in the scene, it ended up being perfect.

She got emotional while reading it, and the tears came naturally.

“[The tears] were not intentional.

Harrison Ford, in an intense scene from a movie, walks inside a dimly lit location, wearing a coat over a shirt and hoodie

But [when it came to filming], I never expected that I was going to start crying.

It ended up being one of the most memorable moments of the film.

The moment made his character Jack appear flustered, which was perfect for the scene.

Top: Close-up of Joker's face on TV screen with GCN news banner. Bottom: Alfred and Bruce Wayne in suits looking serious. Text: Joker speaking about Batman

11.Joaquin Phoenix studied wild animals in captivity for his prison cell scene inThe Master.

Smashing the toilet wasn’t in the script; it was just a part of him going berserk.

“I didn’t intend to break the thing,” Phoenixsaid.

A person in a dark coat interacts with a vintage refrigerator in a dimly lit kitchen in three sequential images

“I didn’t know that was possible.”

inGentlemen Prefer Blondes.One of the dancers, Ed Fury, accidentally pushed her in with his foot.

He was then fired because he tried to claim co-choreographer credit for the mistake.

A person is standing in a dimly lit room, opening a cabinet, partially visible. Shelves with various items are seen in the background

was theresultof an accident.

But in the first shot, a car ran the light and almost hit them.

Staying in character, Ratso yelled, “I’m walking here!”

A scene from "The Lord of the Rings: The Two Towers." Aragorn, played by Viggo Mortensen, looks distressed and kicks a helmet, screaming and falling to his knees

Sylvester Stallone caught it and went with it.

It ended up becoming a signature part of his character.

16.In1917, Schofieldwasn’t supposedto fall an extra ran into him, causing him to fall over.

Julia Stiles from "10 Things I Hate About You" crying while reciting a monologue; text overlay reads part of her speech about not hating someone at all

He got back up again and kept running.

“Im obviously a little biased, but its one of my favorite scenes of the film.”

“It was actually by accident,” hesaid.

Three scenes from a movie: a person saying, "Over on the bed," then correcting to "The couch," and finally, a person screaming and falling to his knees in an outdoor setting

And it was just one of those things.”

It made the scene even more terrifying, and Calvin seem even more unhinged.

However, director Martin Scorseseended uploving it, saying, “The edge fog became the resurrection.”

the toilet seen through the cells bars in pieces

22.The sound of lightsabers inStar Warswas actually created through a happy accident.

25.And the laughing in the lineup scene wasn’t supposed to happen either it wasmeantto be serious.

But we would lose it over and over and over.

the divers dive into the water while jane is crouched down and then gets knocked in by one of the diver's foot

26.The tender moment when Adrian hesitates to kissRockyactually occurred because actor Talia Shire was sick.

They continued with the shot, which the cinematographercalleda “miracle.”

30.This Pearl Harbor scene fromTora!

hey i'm walking here! and a taxi driver yells, up yours

Tora!featuring people running from an exploding plane that happened by accident.

Thiswasn’t supposedto happen, and the stunt people running from the flames were really running for their lives.

The footage was that much more terrifying because it was real.

circle around the orange in the air

“It was probably some of the best footage that we shot that day.”

33.The helicopter crash inAttack of the Killer Tomatoeswas not meanttohappen.

It really did accidentally crash and burst into flames…which was caught on film.

the joker licking his lips

So, they decided they might as well use it.

34.The cat Don Corleone creepily (yet iconically) pets inThe Godfatherwasnotin the script.

In fact, italmost ruinedmultiple takes from purring too loudly.

soldiers running in the field and one of them falling

This made Brasi far more layered and memorable.

daniel getting out of the water

leo's hand bleeding in the scene

A man with long hair and a beard, wearing tattered clothing, stands with arms raised and a look of anguish on his face, with fire visible in the background

her running and then tripping

A film scene featuring Jude Law and Gretchen Mol. Gretchen asks, "Do you wanna come?" Jude replies enthusiastically, "Yes. Yeah. Yeah!" and "Yes! Yes!"

two of the characters fighting with the light sabers

looks like the characters is crying

A person extends their hand while speaking animatedly at night, wearing a light jacket over a dark shirt

After "Number 3, step forward" line, Benicio starts talking, a costar hits him and laughs, and he says "Hand me the fucking keys, you cocksucker; what the fuck?"

A man leans in to kiss a woman, closely facing each other in an intimate moment

Hiccup from How to Train Your Dragon extends his hand to touch the nose of Toothless, the Night Fury dragon

A man watches from behind a barricade as a tank advances down a war-torn urban street, with a burning building in the background

A person, dressed in a sleeveless shirt, hangs from an overhead support, swinging using their arms in an intense, cinematic action scene

Stuntpeople running from the crash

Two men in a bar scene. Top: Timothy Dalton speaks, "Let's say we drink to their demise." Middle: Simon Pegg replies, "Shouldn't that be, 'drink to their memories'?" Bottom: Dalton raises glass, "Of course."

Top: Man and woman standing; man says, "You're welcome to anything I have." Bottom: Man clutches stomach, and woman stands beside him

Series of three images showing scenes from a movie: a police car with siren on and a helicopter crashing, a moustached man in a sheriff's hat, and a helicopter wreck on fire

Marlon Brando as Don Vito Corleone in a tuxedo holding a cat, seated at a desk with blinds in the background, in a scene from "The Godfather."

A man in a tuxedo with a bow tie sits in front of a brick wall and door, holding a napkin, looking serious

she screams as the car hits her

house burning