50 Famous Movie Lines That Were Ad-Libbed

A screenwriter can spend months, or even years, perfecting a script. However, sometimes, the most iconic lines uttered on the silver screen aren't the result of a writer at the top of his or her game, but rather an actor offering up some creative ad-libbing.

If you want to know which of your favorite stars are amazing improvisers, we've got you covered: we've compiled the 50 greatest ad-libbed lines of all time, from the hilarious to the tear-jerking. So read on, and remember: Spoilers lay ahead. And if you want to improve your own ability to make quick-witted quips, discover these 15 Easy Ways to Be More Funny.

The most famous like from Titanic wasn't even in the script. When Leonardo DiCaprio got on the ship for the first time, he shouted the phrase, and James Cameron liked it so much that he put it in the movie. And for more trivia about your favorite movies, check out these 30 Movie Facts That Will Blow Your Mind.

The now classic line in Dazed and Confused that properly introduced the world to Matthew McConaughey was an ad-lib by the actor himself. McConaughey wasn't originally supposed to be in the scene, but the director decided to throw him in and gave him 30 minutes to prepare. The rest is history.

Jack Nicholson shouting "here's Johnny" is undoubtedly one of the most memorable moments from The Shining, but the line was made up by Nicholson, who destroyed nearly 60 doors trying to get the scene right. Perhaps even more surprisingly, the line almost didn't make it past the cutting room. And to learn more about The Shining, discover the 15 Most Haunted Places in America.

The cast of Anchorman, famously full of improvisers, was likely full of whimsical additions to the script. However, the line "I'm in a glass case of emotion," uttered by Will Ferrell, is so perfect that it's hard to believe it wasn't scripted. And if comedy is your thing, check out The 30 Funniest Movies of All Time.

Even people who've never seen Jaws know this line, but it wasn't actually in the original script. The line was something of an on-set inside joke about a too-small boat the production team was using, and actor Roy Scheider tossed it out in a few different scenes during filming before coming up with a delivery and context that made it into the final cut. And for more on how Jaws influenced the future of film, Here's the Biggest Summer Blockbuster Every Year Since Jaws.

This line is practically the unofficial tagline of The Warriors. However, quite surprisingly, it was improvised by David Patrick Kelly, who channeled a neighborhood bully for inspiration.

The Shining isn't the only movie Jack Nicholson has lent his improvisational talents to. His original line in A Few Good Men was "you already have the truth," but he came up with this classic instead. And if you want more great movie lines, learn the 37 Movies Every Man Over 40 Should Be Able to Quote.

Joe Pesci's now-famous rant in Goodfellas was based on a story from his real life. He partially improvised the scene with Ray Liotta, while the other actors had no idea what they were in for.

This classic line from Casablanca wasn't in the original script. Rather, it was something Humphrey Bogart said to Ingrid Bergman when he was teaching her how to play poker offscreen, and he brought it into the film. And to see how not to end a movie, discover The 30 Worst Movie Endings of All Time.

It may be one of the most frequently quoted lines in film history, but all the credit for this iconic utterance goes to Dustin Hoffman. The actor was genuinely yelling at a car that tried to cut him off in the middle of shooting a scene for Midnight Cowboy when he came up with it.

Harrison Ford thought that saying "I love you too" to Princess Leia in The Empire Strikes Back would be out of character for Han Solo, so he said "I know" instead.

Robert DeNiro's famous scene with himself in Taxi Driver was entirely improvised. The script merely said that he "speaks to himself in the mirror," and DeNiro took it from there, coming up with this memorable monologue.

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Rutger Hauer's speech at the end of Blade Runner is regarded as one of the great death monologues in film history, made even more impressive by the fact that it was unscripted. Hauer changed the speech and performed it the way you see it without telling anyone he was going to, and some members of crew were so moved that they actually cried.

Not only was this line not written in the Being John Malkovich script, but neither was the beer can getting chucked at John Malkovich's head. Both were the idea of a random drunken extra, and the scream of pain you hear is very real.

During rehearsals for Voldemort's big speech in Harry Potter and the Deathly Hallows, Part 2, Ralph Fiennes never delivered his lines the same way to keep all the extras and actors on their toes.

When filming the final line for Good Will Hunting, they shot take after take, with Robin Williams improvising a different line each time. However, this ad-lib was so perfect it made it into the movie's final cut.

Arnold Schwarzenegger has so much practice dropping one-liners that this classic line from Terminator 2 is 100 percent him.

Whoopi Goldberg had some fun with the script for the movie Ghost, as evidenced by this iconic ad-libbed line. She must have been onto something, since she ultimately won an Academy Award for her performance.

So much of This Is Spinal Tap—including this beloved line—is improvised that the three main actors are all given writing credits.

Malcolm McDowell decided to start singing "Singing in the Rain" during the home invasion scene of A Clockwork Orange. Director Stanley Kubrick liked it so much it made it into the film.

This line ad-libbed by Cary Grant in His Girl Friday is especially notable since Archibald Leach was Grant's actual name.

After spending the entirety of Dr. Strangelove sitting in a wheelchair and stifling Nazi salutes, Peter Sellers dropped this ad-lib as the perfect line to end the film.

Originally, there was nothing in the Reservoir Dogs script about Michael Madsen talking into an ear he'd recently severed, but apparently inspiration struck in the moment, and now the movie has this memorable, if grim, joke.

Nick Frost's descriptions of the pub-goers in Shaun of the Dead were all improvised, so Simon Pegg's laughter was a genuine reaction.

In Tootsie, Bill Murray was tasked with coming up with dialogue to make it seem like he'd been sitting at a table and talking all night, and that is exactly what he did, offering up some of the funniest lines in the movie.

Major spoiler alert! Director Joe Russo let Tom Holland improvise Spider-Man's final words in Avengers: Infinity War, giving him only the direction to act like he wasn't ready to die. Holland's final lines left audiences around the world who couldn't believe what they'd just seen heartbroken.

Director Rob Reiner let Billy Crystal have some fun with the dialogue in When Harry Met Sally, which resulted in several now classic moments. That includes both the infamous deli scene and the charming interplay between Crystal and Meg Ryan that had them both speaking alliteratively in wacky voices.

John Belushi's impersonation of a human zit in Animal House was a totally improvised moment that brought both gross-out comedy and Belushi himself into the mainstream.

Orson Welles made up this little speech in The Third Man, which kind of makes sense. After all, you'd basically have to be Orson Welles to have the courage to mess with a script written by Graham Greene, who is widely considered one of the great writers of the 20th century.

Marlon Brando showed up for Apocalypse Now very overweight and not knowing his lines. The end result is a lot of footage of Brando hidden in darkness saying made-up nonsense like this.

Marty Feldman's hump frequently switched sides over the course of Young Frankenstein, but perhaps the best hump joke was this unscripted moment when Feldman acted like he was unaware of the hump's existence.

This bit of snark in The Devil Wears Prada wasn't in the script. Rather, Emily Blunt heard a mother say it to her daughter at a shop and decided to bring it into the movie.

There was quite a bit of improvising in Wonder Woman, and Chris Pine definitely had some fun in this scene on the boat, according to director Patty Jenkins.

Fresh off an Oscar win for best original screenplay, Matt Damon must have been feeling pretty confident when he improvised an entire story during filming of Saving Private Ryan.

In Bridesmaids, Melissa McCarthy had a lot of fun improvising innuendo and flat-out dirty comments to the air marshal on her flight, which makes sense. The actor playing the air marshal, Ben Falcone, is McCarthy's husband in real life.

The line Tommy Lee Jones was originally supposed to say in The Fugitive after Harrison Ford asserts that he didn't kill his wife was "that's not my problem." But Jones went with "I don't care" instead.

When Sean Connery tossed out this ad-lib in Indiana Jones and the Last Crusade about how he knew a woman was a Nazi, the entire set burst out laughing, and the line stayed in the film.

Anthony Hopkins only had 25 minutes of screen time in Silence of the Lambs, but that was enough to garner him an Oscar, thanks to creepy moments like this one, where he followed up a line about eating a census taker's liver with a disturbing hissing noise that was not in the script.

Actor Richard Castellano's original line in The Godfather was simply "leave the gun." Castellano decided to have a little fun and added on "take the cannoli," and in doing so, he created one of the most popular lines from the film.

Caddyshack director Harold Ramis told Bill Murray to make up a speech in the style of a sports commentator, and Murray delivered this classic monologue about a real Cinderella story.

Josh Gad got to have some fun during the production of Frozen, but even he was surprised when the line "I've been impaled," which he improvised during recording, made it into the movie.

Former drill sergeant R. Lee Ermey came up with pages and pages of insults for Full Metal Jacket, and only the best (or worst, depending on your perspective) made it into the film.

The script for Lost in Translation originally called for Bill Murray and Scarlett Johansson to hold hands. Instead, they kissed, and Murray whispered something into Johansson's ear. Only the two actors knew what was said, and both refused to tell.

Ben Stiller improvised this line in Zoolander when he forgot what he was supposed to say. Rather than break character, he decided to repeat his last line again, and David Duchovny stayed in character to respond, which gave this ad-lib a permanent spot in the movie.

Donald Faison decided to say "I'm keeping it real" in Clueless because he heard a kid in his neighborhood say it and decided it would add a little authenticity to his part.

Bill Paxton improvised these lines in Aliens, which James Cameron kept in the final cut.

Jim Carrey was on a roll during the filming of Dumb and Dumber. Much of the film was improvised, including the "most annoying sound in the world."

The moment when Aragorn kicks a helmet, then drops to his knees screaming wasn't in the script for The Fellowship of the Ring. It was actor Viggo Mortensen's reaction to accidentally breaking his toe.

The notorious waxing scene in The 40-Year-Old Virgin was completely improvised. Judd Apatow basically set up a camera and filmed Steve Carell getting his chest waxed for the first time. Carell's pain, and ad-libs, are very real.

Tom Felton made up this little insult in Harry Potter and the Chamber of Secrets, and it stayed in the final cut, helping to paint a picture of Draco Malfoy as a little bully. And for more zingers from little kids, check out The 20 Funniest Jokes from Kids' Movies.

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