1.
According to the DVD Commentary for Austin Powers: Goldmember, the part where Austin pees next to the fountain — and his stream comes out in little spurts — was an accident. In the film, Austin trips on a cord and accidentally unplugs a water fountain, so he jumps behind it and starts peeing to make it look like it’s still going. But when the water pump used to simulate Austin’s stream started spurting (because it was running out of water), the filmmakers thought it was funny and decided to incorporate that into the scene by having Austin pee in spurts.
2.
One of the most iconic Raiders of the Lost Ark scenes, where Indy simply shoots a man whipping around a sword, was a last-minute change. There had been a ton of planning and rehearsal for an elaborate fight scene, but on the day of, Harrison Ford was sick with dysentery and couldn’t film for more than 10 minutes at a time. When he got to set, he suggested he just shoot the swordsman instead — and the rest is history.
3.
While this wasn’t intended to be funny, it kind of became a running gag that Michael Keaton couldn’t turn his head in his suit in Batman, meaning that every time he turned, he had to turn his whole body. It was even referenced in a Deadpool joke. This was not intentional — the suit really was too stiff for Keaton to turn just his head.
4.
We can’t 100% confirm this, but according to legend, Carol Channing’s character in Thoroughly Modern Millie was actually supposed to blow a raspberry in the below scene. However, Channing misunderstood the script direction and yelled “RASPBERRIES” instead.
5.
Rachel McAdams’ scream when the broom behind her falls in Doctor Strange is real — the hilarious moment happened by accident, as McAdams was in character and feeling easily startled after her character saw a portal.
6.
In Boogie Nights, William H. Macy’s character was meant to say “cock in her ass,” but kept accidentally saying “ass in her cock.” The director, Paul Thomas Anderson, thought it was funny and kept it. The funny moment only serves to make his character seem more flustered.
7.
In The Amazing Spider-Man 2, according to the DVD commentary, the funny moment where Gwen accidentally reveals Spider-Man’s identity was a complete accident — Emma Stone yelled his name in character, then covered her mouth when she realized that Gwen should not be shouting Peter’s real name out loud in public. The silly moment even appeared in the trailer.
8.
In Clueless, Alicia Silverstone actually thought “Haitians” was pronounced that way, and the director, Amy Heckerling, thought it was so funny that she declined to correct her.
9.
Costar Hank Azaria revealed that Robin Williams’ fall in The Birdcage was accidental. “If you watch that little piece of film again, you’ll see me laughing and Robin laughing. It’s one of those things that happens that you never really think they’re going to use, but I was so emotionally upset in the scene — I was supposed to be crying — that I just pretended that he was making me cry even more. But I was actually laughing.”
10.
General Turgidson’s hilarious fall in Dr. Strangelove was also completely accidental.
11.
In Cheech & Chong’s Up in Smoke, the dog that eats Chong’s burrito was a real stray that just wandered up and ate the burrito. It wasn’t in the script.
12.
In A Knight’s Tale, the crowd was supposed to cheer at Chaucer’s speech. However, many of the extras did not speak English and didn’t realize it was time for them to cheer. Mark Addy then started cheering to get the extras to join in — a funny moment that director Brian Helgeland kept in.
13.
In Zoolander, Ben Stiller had actually forgotten his line after JP Prewitt explained why he was using male models, so he just repeated his last line again. The actor playing Prewitt, David Duchovny, ad-libbed a reply, and the exchange ended up in the film.
14.
In The Princess Diaries, Mia’s fall on the bleachers was completely accidental — Anne Hathaway really did fall (the bleachers were slippery because it had just rained) but it was so funny it was left in.
15.
In How the Grinch Stole Christmas, the Grinch was supposed to knock over everything on the table when he pulls the tablecloth. However, Jim Carrey accidentally performed the trick flawlessly, and everything stayed where it was on the table — this resulted in Carrey improvising pushing everything off.
16.
According to audio commentary for Scream, Skeet Ulrich didn’t mean to hit Matthew Lillard in the head when he slammed the phone down — the fake blood on his hand made it slip. Lillard then improvised his iconic line: “You fuckin’ hit me with the phone, dick!” Lillard’s reaction was so good, it was kept in.
17.
This isn’t quite a *mistake,* but I love it so much that I have to include it…Lillard also improvised the line, “My mom and dad are going to be so mad at me.”
18.
In Guardians of the Galaxy, Peter wasn’t meant to drop the orb in the scene where it slips from his hand and he quickly catches it. That was actually Chris Pratt accidentally dropping and catching it.
19.
In Scrooged, Bill Murray’s character wasn’t supposed to fall after throwing water on the waiter. Murray accidentally slipped on the water on the floor, and it was so funny that they kept it in.
20.
The scene in Mrs. Doubtfire where Daniel sticks his face in a cake to avoid being recognized was planned — but the crew didn’t realize the heat from the lighting would melt the frosting, causing it to fall into Mrs. Sellner’s tea.
21.
The funny line from Ant-Man and the Wasp: Quantumania, where a worker confuses Ant-Man for Spider-Man, was actually an accident — the actor confused the two characters.
22.
Similarly, Dustin Hoffman actually accidentally farted in the phone booth scene in Rain Man, and Tom Cruise’s reactions were improvised. Hoffman called it his “favorite moment” of any film he’s done. “That includes Shakespeare that I’ve done on stage, anything.”
23.
In the scene from The Mask when Stanley tries to stuff the money in the closet, Milo wasn’t supposed to bite the frisbee — the Jack Russell terrier actually did jump and bite the frisbee, holding on for dear life. This was so funny, they decided to incorporate it into the movie.
24.
Terry wasn’t meant to crash his scooter in American Graffiti — that was a funny accident that made it into the film.
25.
Alvy’s sneeze — sending his friend’s expensive cocaine into a cloud — in Annie Hall was unscripted and accidental. Ruining his friend’s coke was so in-character for Alvy and funny that it stayed in the film.
26.
The elephant next to Ewan McGregor’s character in Big Fish was not meant to poop during the circus scene where he’s cleaning their enclosure – however, it worked perfectly to comedically contrast Edward’s mood. “How amazing was that moment when the elephant craps on screen? We’d shot the wide shot where you see the two elephant’s bums and then me. We’d shot that and we’d moved in to do a close-up. … As we were setting that up, it lifted its tail and we all went, ‘Quick!’ and they widened the camera out, I got ready, and there was no turnover. They just turned the camera on and I played the scene as it dumped next to me. Genius,” McGregor said of the scene.
27.
Another funny scene that wasn’t meant to happen was Joel throwing the arrow on the ground in Addams Family Values. The actor, David Krumholtz, couldn’t get the arrow on the bow. “So, in real-life frustration, that’s me throwing it down and walking out,” Krumholtz said. “I was super angry at myself. Then, after they cut, they all started laughing, and they were like, ‘That was hilarious!’ I was like, ‘Oh! OK!'”
28.
And finally, let’s throw it back old school. The crashing after Uncle Billy walks offscreen in It’s A Wonderful Life wasn’t planned — a bunch of props were dropped right as he walked offscreen, and Thomas Mitchell (who played Billy) improvised “I’m alright!” pretending the crash was him. James Stewart’s laugh is real.