Much to the dismay of screenwriters, movies scripts aren't always set in stone - and some of the best scenes are actually unscripted. They are often like living objects constantly evolving during the filming process. Some films, like Jaws and Annie Hall, don't even have a finished script when the cameras start to roll.
Actors and actresses are regularly ad-libbing, improvising or going off-script while reciting their lines. Sometimes the directors hate it - other times they love it. Occasionally the improved lines become immortalized as some of the most memorable in cinema history.
Check out these 32 great unscripted scenes - you may be surprised at how many of your favorite lines were off-the-cuff.
Last updated: March 31
This Page: Raiders of the Lost Ark, The Dark Knight & More
32. Raiders of the Lost Ark - Gun vs. Knife
While chasing Marion Ravenwood (Karen Allen) after she's been kidnapped, archaeologist and adventurer Dr. Indiana Jones (Harrison Ford) runs into a large sword-wielding bad guy dressed all in black. Instead of fighting him in what would surely be a losing whip versus sword battle, Indy simply pulls out his revolver, puts the man down with one shot and moves on.
The original Raiders of the Lost Ark script called for a long sword fight but a day earlier Ford got a severe case of food poisoning and didn't have the energy to film the scene as written. After a discussion with director Steven Spielberg, the scene was changed and became an iconic part of Indiana Jones mythos.
31. Zoolander - Why Male Models?
In this Zoolander scene involving former hand model J.P. Prewitt (David Duchovny) and the dimwitted male model Derek Zoolander (Ben Stiller), Prewitt - a conspiracy theorist - explains how the fashion industry has been behind every high profile political assassination of the last hundred years.
Zoolander asks, "Why male models?" Prewitt answers with a lengthy explanation, after which Zoolander responds again, "Why male models?" Stiller forgot his original line and just repeated his previous line instead. This prompted Duchovny to ad-lib his response "Are you kidding? I just told you like a minute ago."
The scene ends up reinforcing the movie's narrative of the brainless male model stereotype and Stiller turned a gaffe into one of the funniest parts of the film.
30. The Godfather - Don Vito Loves Cats
The Godfather's Vito Corleone (Marlon Brando) is more than the cold-hearted head of a powerful Italian mob family. That trait shows when he sentences a man to be beaten as retaliation for the beating of another man's daughter - all while gently stroking a cat.
Thing is, the cat was never part of the original script. Some reports say that Coppola plopped the feline into Brando's lap just before filming began. Other reports say Brando found "il gatto" roaming around the set, picked him and gave him an offer he couldn't refuse (heh).
29. The Fugitive - Tommy Lee Jones Doesn't Care
In this famous showdown between Richard Kimble (Harrison Ford) - a doctor wrongly accused of murdering his wife - and U.S. Marshal Samuel Gerard (Tommy Lee Jones), Kimble gets the jump on Gerard in the sewers. Instead of shooting the Marshal and making things worse, Kimble pleads his case to him saying, "I didn't kill my wife!" Gerard, with a sober tone and intense look on his face, responds with a simple, but brilliant and ad-libbed, piece of dialog, "I don't care."
The line wasn't part of The Fugitive's script but those three words reinforced to Kimble, and audiences, that it didn't matter to Gerard whether the doctor was guilty or innocent of the crimes for which he was accused. He was going to get his man - no matter what.
28. The Dark Knight - The Joker's Creepy Clap
As The Dark Knight's lead villain The Joker (Heath Ledger) waits quietly alone in jail after having been arrested by Jim Gordon (Gary Oldman), Mayor Garcia (Nestor Carbonell) shows up to look over Gotham's latest scourge. While there he also promotes Gordon to the position of Commissioner.
As the officers in the room applaud the announcement Ledger begins, unscripted, to slowly clap - never changing his facial expression. It was just a simple improvisation but one that was unsettling and darkly brilliant.
27. Robocop - Give Me My Phone Call
When antagonist Clarence Boddicker (Kurtwood Smith) is taken to the police precinct after receiving a solid whooping by Robocop (Peter Weller), Boddicker spits a bloody glob onto the paperwork of the desk sergeant, followed by the line "Give me my f*ckin' phone call!"
Smith and Verhoeven briefly had discussed the unscripted moment before filming the scene but neglected to inform the extras - which was evident by their real and disgusted surprise as the scene unfolded.
26. Pretty Woman - The Jewelry Box Surprise
In one of Pretty Woman's most famous scenes, Edward Lewis (Richard Gere) presents call girl Vivian Ward (Julia Roberts) with a gorgeous and rather expensive diamond necklace. As Roberts reaches out to touch the precious jewels, Gere - in an unscripted playful moment - quickly snaps the box shut genuinely surprising her.
Her laugh was so honest, and the scene so good, that Marshall decided to leave it in the film as is.
25. Being John Malkovich - Hey Malkovich! Think Fast!
Shortly after John Malkovich meets Craig Schwartz (John Cusack) on the side of the road he wanders off mad. As he does, a car passes by with a man leaning out the window. The man throws a can hitting Being John Malkovich's titular star square in the back of the head while yelling, "Hey Malkovich! Think Fast!" - causing the Oscar nominated actor to scream out in legitimate pain.
Neither the can throwing nor the reaction were scripted but the drunken extra in the car felt the opportunity was too good to pass up. Jonze thought the scene added to the character's frustration and left it in.
Instead of being fired, the extra was added to the final cut of the film and given a raise.