Some of the most memorable movie moments weren’t created by writers—it was all improvised on the spot. Whether actors were cracking each other up, responding in the moment, or simply sensing their character was going to go a different way, these spontaneous treasures wound up becoming iconic. Here are ten of the best improvised lines in movie history—counted down in reverse order, just for kicks.
10. “Sublime!” – Barbie (Ryan Gosling)
Ryan Gosling’s Ken wasn’t even amusing due to what was on the page—he kept slipping in his flourishes. Best of all? His over-the-top “SUBLIME!” when Barbie says yes to his half-baked girlfriend’s request. Margot Robbie later said that Gosling’s improvised lines brought the entire cast and crew to tears, and it’s not hard to understand why this one took hold.
9. “I didn’t know you could read.” – Harry Potter and the Chamber of Secrets (Tom Felton)
Tom Felton, only 13, threw in a superbly smarmy Draco Malfoy put-down when Crabbe and Goyle (in reality, Harry and Ron in disguise) were having a hard time explaining themselves. His improvised line got precisely the laugh the scene required—and landed a permanent place in the movie.
8. “He stole my line.” – Good Will Hunting (Robin Williams)
Robin Williams was known not to leave scripts alone, and this sweet line is one of the most popular of his ad-libs. As the final shot of the movie, after reading Will’s letter, Williams improvised the response. Matt Damon has called it his favorite unscripted Williams moment, and the director knew in an instant that it had to remain.
7. Hannibal’s hiss – The Silence of the Lambs (Anthony Hopkins)
Anthony Hopkins’ chilling hiss after detailing his gruesome dining rituals to Clarice wasn’t in the script. Hopkins had been playfully teasing Jodie Foster, then thought, Why not? And tossed it in while filming. The result? One of the most—best-ever shuddery moments in horror history.
6. “I love lamp.” – Anchorman (Steve Carell)
When director Adam McKay told Steve Carell to “just say something” in character, Carell glanced around and blurted, “I love lamp.” Will Ferrell immediately played along, turning a random improv into one of the most quoted lines in comedy.
5. “I’m walkin’ here!” – Midnight Cowboy (Dustin Hoffman)
Filming on real New York streets meant surprises—like when a cab nearly hit Dustin Hoffman. Staying in character as Ratso Rizzo, Hoffman slammed the hood and shouted, “I’m walkin’ here!” He later admitted he almost yelled, “We’re making a movie here!” but changed his mind mid-sentence. Good thing he did—this ad-lib became pure New York legend.
4. “You talking to me?” – Taxi Driver (Robert De Niro)
The script simply said, “Travis talks to himself in the mirror.” Robert De Niro took it further, improvising the now-famous “You talking to me?” monologue. Screenwriter Paul Schrader later admitted it was the best part of the movie—and one he never wrote.
3. “You’re gonna need a bigger boat.” – Jaws (Roy Scheider)
The cast frequently cracked jokes about the too-small support boat employed during filming, and Roy Scheider incorporated the line into his dialogue a few times. When he spoke following that initial frightening shark encounter, it was so ideal that it became instantly iconic.
2. “I know.” – Star Wars: The Empire Strikes Back (Harrison Ford)
Leia tells Han Solo that she loves him. Han Solo was expected to say, “I love you, too.” Harrison Ford thought that didn’t sound good—so instead, he said, “I know.” The alteration not only suited Han so well but also turned out to be one of the greatest one-liners in film history.
1. “Here’s looking at you, kid.” – Casablanca (Humphrey Bogart)
Bogart employed the line off-camera while instructing Ingrid Bergman in how to play poker. He inserted it into the movie when the cameras were rolling. The writers enjoyed it so much that they had him deliver it over and over again. Decades on, it is one of cinema’s most lasting romantic lines.
What all of these moments demonstrate is straightforward: occasionally, the greatest moments of a film are not scripted. A misplaced word, an off-the-cuff joke, or a gut feeling might become a line that defines a character—or a film in its entirety. Whether improvised or not, they remind us why films feel so real: because sometimes the greatest magic occurs when nobody anticipates it.