No matter how meticulous the script, many film directors give their actors at least some leeway when it comes to improvisation. As Guy Richie, director of Lock, Stock and Two Smoking Barrels, once said: “I like to think that we’ve got a plan, so let’s stick to it. That said, once we’ve stuck to it, we’re allowed as much improvisation as anyone cares to indulge themselves in.”

The power of true improvisation reveals itself in some of cinema’s most quoted lines, from Robert De Niro’s “You talkin' to me?” to Jack Nicholson’s “Heeeere’s Johnny!”

But some famous movie quotes frequently cited as improvised aren’t quite what they seem. When Princess Leia tells Han Solo she loves him, Han responds with the now-iconic line, “I know.” But while Harrison Ford did come up with the line, he had discussed it previously with director Irvin Kershner. The same is true of Rutger Hauer’s “Tears in the rain” monologue in Blade Runner — often said to be improvised — which he wrote the night before the shoot.

The following quotes are all examples of genuine improvisation: famous lines that were never in the script and never discussed with the director, and that went on to become classic moments in movie history.  

Here’s looking at you, kid.
– Humphrey Bogart in "Casablanca," 1942

Bogart improvised this classic line, although he had used it before in Midnight in 1934.

Mein Fuhrer, I can walk.
– Peter Sellers in "Dr Strangelove," 1964

Sellers improvised many of his lines in this Stanley Kubrick classic, including the final line (spoiler alert) when Strangelove steps out of his wheelchair.

Hey! I'm walkin’ here!
– Dustin Hoffman in "Midnight Cowboy," 1969

Hoffman shouts this iconic line when he almost gets hit by a cab. There’s some debate as to whether it was improvised or not, but Hoffman claims it was spontaneous.  

Leave the gun, take the cannoli.
– Richard Castellano in "The Godfather," 1972

The original script just said “Leave the gun,” but Castellano, who played Clemenza, improvised the rest after a suggestion from his onscreen and real-life wife, Ardell Sheridan.

You’re gonna need a bigger boat!
– Roy Sheider in "Jaws," 1975

Sheider’s famously improvised line was actually an inside joke among the crew, who had been given a tugboat too small for the shoot and used the line among themselves, totally unaware that it would become part of cinematic history.

You talkin' to me?
– Robert De Niro in "Taxi Driver," 1976

One of the most iconic lines and scenes of all time was completely improvised by De Niro. Director Martin Scorsese asked the actor “Can you say something to yourself? In the mirror?” and so was born the famous scene.

Heeeere’s Johnny!
– Jack Nicholson in "The Shining," 1980

Nicholson’s axe scene remains one of the most chilling moments in horror history, and his most famous line was totally improvised.

Game over, man! Game over!
– Bill Paxton in "Aliens," 1986

Paxton was improvising when his character, Private First Class William Hudson, starts to freak out after his dropship is destroyed. He had no idea at the time that his ad libbed lines would become one of the most famous quotes in sci-fi movie history.

You can't handle the truth!
– Jack Nicholson in "A Few Good Men," 1992

The original script had Col. Nathan Jessup saying, “You already have the truth,” but Nicholson improvised a line that was far more memorable.

I love carpet. I love desk. I love lamp.
– Steve Carell in "Anchorman: The Legend of Ron Burgundy," 2004

Carell’s weatherman Brick Tamland is one of the highlights of Anchorman, and his lamp scene is one of its funniest moments. He improvised the scene because director Adam McKay told him he didn’t have any written lines, so “Just say something.” And that’s exactly what Carell did.

I am Iron Man.
– Robert Downey Jr. in "Iron Man," 2008

When Tony Stark reveals to the world that he is, in fact, Iron Man, Downey Jr. wasn’t following the script. He improvised the line, which became one of the most iconic quotes in the Marvel Cinematic Universe.

I've been impaled.
– Josh Gad in "Frozen," 2013

Olaf the Snowman is one of the most beloved characters in Frozen, which at the time of its release was the highest-grossing animated film of all time. Actor Josh Gad, who voiced lovable snowman Olaf, was surprised when one of his ad libbed jokes made it into the final cut, perhaps because impaling isn’t typically a subject for a family movie.

I don’t want to go.
– Tom Holland in "Avengers: Infinity War," 2018

Major spoiler alert: One of the most heartbreaking lines in the superhero movie comes from Holland's Peter Parker moments before he fades away. Co-director Joe Russo didn’t have any lines for the young actor, simply telling him to act like he doesn't want to leave. Holland improvised the now-classic line, and delivered it perfectly.

Photo Credit:  Juskteez Vu/ Unsplash