Iconic movies with scenes you may not know were improvised

"I'm walkin' here!"

Those three words have become synonymous with New York life, but you might not be aware that it was a line in the classic Academy Award-winning film "Midnight Cowboy"—and not just that, it was fully improvised.

Dustin Hoffman explained that the film was made on a shoestring budget, so they couldn't shut down the city streets despite filming there. Thus, Hoffman's response to a cabbie jumping out in front of him was wholly organic: "I wound up saying, 'I'm walkin' here!' But what was going through my head is: 'Hey, we're makin' a movie here! And you just f----- this shot up.' But somehow, something told me you'd better keep it within the character."

When Henry Hill (Ray Liotta) makes an offhand remark about Tommy DeVito (Joe Pesci) being funny, it becomes a tense, life-threatening moment almost no one saw coming. The unforgettable scene from Martin Scorsese's "Goodfellas" was not only nowhere in the initial script, but it was actually based on something Pesci really experienced in his youth, which he'd relayed to the cast during rehearsal.

Only Pesci and Scorsese knew the story would be improvised within the scene to get genuinely surprised reactions from the other actors; however, the real improvisation happened during rehearsal, which was then written into the script.

The simple, laconic, thrice repetition of the word "alright" has become inextricably linked to Matthew McConaughey, originating from a scene in Richard Linklater's teen comedy "Dazed and Confused." Because it's so simple, it might not be shocking to learn this now-iconic turn of phrase was totally unscripted. While prepping for the role, McConaughey listened to a live album by the Doors and gravitated toward a moment when Jim Morrison said "alright" four times in a row. It was inspiration enough for McConaughey to draw from it for his portrayal of chill party boy David Wooderson.

While Martin Scorsese is known to strictly adhere to a script, one "Taxi Driver" scene had no instruction for Robert De Niro's Travis Bickle. The only note screenwriter Paul Schrader wrote was that Bickle "looks in the mirror and plays like a cowboy, pulls out his gun, talks to himself." Ultimately, Scorsese and De Niro had to figure out what to do, so with the rest of the crew off-set and the two workshopping, the line practically emerged out of thin air, and they went with it. "You talkin' to me?" is now probably the line of dialogue most people associate with the actor and his legendary career.

Even a golden age classic like "Casablanca" was not immune to the kind of movie magic that could be surmised from a little bit of improvising, and fans can look no further than what is arguably the picture's most famous line. At the conclusion, when Rick (Humphrey Bogart) helps his lost love, Ilsa (Ingrid Bergman), get onto a plane to escape authorities with her husband, he says, "Here's looking at you, kid."

Believe it or not, that line wasn't in the script. Apparently, during production, the script was still a work in progress, and Bogart ended up ad-libbing the line during a different scene—the screenwriters included the phrase a couple more times in the script, and it stuck in that now-quintessential scene.

When Jack Nicholson breaks down the door and screams, "Here's Johnny!", while on his murderous, supernaturally influenced rampage in "The Shining," he's referencing Johnny Carson's former nightly intro on "The Tonight Show." The line has since become aligned with "The Shining," perhaps more so than "The Tonight Show." What's more, it was ad-libbed by Nicholson on the spot. As director Stanley Kubrick was infamous for his meticulous shooting and numerous takes, it's a miracle the improv'd line made it into the finished film.

The most famous line from Steven Spielberg's seminal horror blockbuster "Jaws" came about in the moment, but it wasn't wholly organic. Even so, Roy Scheider's utterance of "We're gonna need a bigger boat," about the size of the shark they're up against, has gone down in movie history.

A real-life problem inspired the line: a barge meant to carry set equipment and craft services "steadied by a small support boat that was too tiny to manage the job." Apparently, the producers were stingy guys, and, well, the crew kept telling them… they're gonna need a bigger boat.

Han Solo's response to Princess Leia's admission of love for him with two simple words ("I know") is one of the most romantic exchanges of all time, and rumor has it the line was a moment of brilliant improvisation on Harrison Ford's part. However, maybe not so brilliant.

The truth is the line was never in the script and was born from a moment of on-set actor-director workshopping between Ford and Irvin Kershner. Nevertheless, it was Ford's idea to say the line in the film, and that counts as a bit of movie magic.

Not long after Jack (Leonardo DiCaprio) and his friend Fabrizio (Danny Nucci) win their way onto a doomed trip on the Titanic, they joyously run to the ship's bow and Jack hollers, "I'm the King of the World!" One of the classic romance film's most quotable lines was actually a moment of pure improvisation—not on DiCaprio's part, but on director James Cameron's.

Apparently, while filming, Cameron struggled to come up with a line that perfectly encapsulated the euphoria Jack felt at that moment, and when he eventually landed on "I'm the King of the World," DiCaprio himself was a bit unconvinced—that is, until he ran the scene through, and movie history was made.

"Leave the gun. Take the cannoli" is just one of many unforgettable lines from Francis Ford Coppola's "The Godfather," but it just happens to be the line that came about from a moment of pure inspiration. In the script, the line stopped at "leave the gun," but actor Richard Castellano added a little addendum incited by his on-screen (and real-life) wife, Ardell Sheridan. She suggested Castellano "riff on an earlier scene where she had asked him to pick up the dessert."

Yet another Martin Scorsese film that features some famous improvisation—this time, not a line but a replicable action devised by Matthew McConaughey in his brief role in "The Wolf of Wall Street."

Playing veteran stockbroker Mark Hanna, who mentors Leonardo DiCaprio's Jordan Belfort, the two have a lunch meeting where Hanna gives Belfort advice. Then, he meditatively hums and thumps his chest, encouraging Belfort to emulate him. McConaughey used that same ritual to clear his head before takes, which DiCaprio suggested he incorporate into the film.

Comedy flicks are typically rife with improvisation—and sometimes wholly founded on improvisation with simply an outline of a script to move the narrative from scene to scene. Still, it's often hard to tell which jokes were scripted and which came from organic riffing between actors, especially in a film as joke-filled as "Anchorman." As it turns out, one of the film's most famous lines was improv'd by Steve Carell—whose dimwitted Brick Tamland ran out of lines to say on the page, so director Adam McKay instructed Carell to "just say something."

"You can't handle the truth!" is one of the most repeated movie quotes of all time, uttered by the legendary Jack Nicholson in Rob Reiner's legal drama "A Few Good Men." It's so iconic that you may be surprised to learn Nicholson ad-libbed it on the spot, changing it from the original line, "You already have the truth!" While a slight alteration in wording, it changes the entire intent of the line and benefits the character far better.

Something as beautiful and heartrending as the late Rutger Hauer's "tears in rain" monologue in "Blade Runner" surely must have been in the original script. Well, it was, but Hauer rewrote and improvised a shorter, more poetic version than what was written on the page for his replicant character, Roy Batty.

Speaking with Radio Times in 2017, Hauer explained that he only kept two lines from the original monologue and improvised the rest himself, explaining, "On the day of filming itself, crew members allegedly applauded and cried when the scene was completed."

In Mel Brooks' hysterical send-up of classic, Universal horror films, Marty Feldman plays Igor, Dr. Frederick Frankenstein's creepy assistant who sports a hump on his back. According to behind-the-scenes commentary for the film, Feldman was secretly moving the fake hump around on his back, unbeknownst to director Brooks. When Brooks got wise, he loved the sight gag so much that he wrote it into the script, leading to one of the film's most famous lines: "What hump?"

Anthony Hopkins' chilling portrayal of Hannibal Lecter in "The Silence of the Lambs" earned him an Academy Award with only 16 minutes of screen time. Still, it's one of the most memorable performances ever. And being such a skilled actor, it may come as no surprise that one of the most quoted moments of the film included some improvisation on Hopkins' part.

While the line Lecter says to Clarice Starling (Jodie Foster) about eating a man's liver with "some fava beans and a nice chianti" was in the script, the bizarre slurping hiss he does at the end—an effective complement to this creepy scene—was not; apparently, Hopkins was randomly making the noise while on set and decided to throw it in.

The famously speculated moment of Sofia Coppola's "Lost in Translation" comes at the end, when Bob (Bill Murray) and Charlotte (Scarlett Johansson) share an emotional parting embrace, and Bob whispers something inaudible into Charlotte's ear. While the whisper was intended for the scene, what Murray whispered to Johansson remains a secret.

Moreover, Coppola had not intended for the whisper to remain silent—she was originally going to record their dialogue for the whisper in post-production. Speaking of the scene for BBC Four's "Life Cinematic," Coppola explained: "In the editing, we were like, 'Oh, it's better if it's just between them and the audience puts their own interpretation.'''

The "Harry Potter" film series isn't known for being particularly comedic. Still, one of the funniest moments of its seven films was unscripted, courtesy of a young Tom Felton, the actor who played Draco Malfoy.

In the second film, "Harry Potter and the Chamber of Secrets," Harry and Ron Weasley drink a Polyjuice Potion and go undercover as Malfoy's goons, Crab and Goyle, to glean information about the Chamber from their arch-nemesis. Their identities are nearly revealed when Malfoy asks Harry, disguised as Goyle, why he's wearing glasses; Harry answers that they're for reading, and a confused Malfoy replies, "I didn't know you could read."

According to Felton himself, he forgot his actual line and came up with one on the spot.

Probably one of the most repeated superhero movie quotes of all time, Michael Keaton's simple, growled utterance, "I'm Batman," in Tim Burton's 1989 film cemented Keaton's Batman portrayal as one of the superhero greats—even if his casting was controversial at the time. Well, the "I'm Batman" line wasn't even in the script—it resulted from Burton and Keaton agreeing on a last-minute change. And believe it or not, according to Keaton, there were more improvisations in the film where that came from.

You probably wouldn't consider "James Bond" legend Sean Connery a master of improv, but he got to flaunt his skill during a scene with Harrison Ford in "Indiana Jones and the Last Crusade." Arguably the funniest installment of the "Indiana Jones" franchise, much of which can be credited to Connery, who plays Jones' father. Connery is credited as having devised one of the funniest scenes in the film on the spot. When Indy asks his dad how he knew an art professor was secretly a Nazi, he replies, "She talks in her sleep," everyone causing everyone on set to burst into hysterics.

Next time you watch "Good Will Hunting," look closely to see if you notice the camera shaking during one particular scene with Robin Williams—that's because the cameraperson was laughing at Williams' improvisation. The scene where Maguire (Williams) and Hunting (Matt Damon) are discussing Maguire's deceased wife veers wildly off-course when Maguire states, off-the-cuff, that his wife "used to fart in her sleep." Hunting erupts into laughter at the line, which was Damon's genuine reaction.

Sometimes, a film's most iconic line comes about from a moment of pure revelation; sometimes, that line just happens to be the most of that actor's career.

As director James Cameron revealed to The Hollywood Reporter, that was indeed the case for Arnold Schwarzenegger's brooding threat in "Terminator 2: Judgment Day," "I'll be back," which was never in the original script. "In the script, it actually read, 'I'll come back,'" Cameron explained. "And there was something about the way Arnold said it with his then-quite-thick Austrian accent that didn't sound quite right. So I just said, 'We will just switch it to I'll be back.'"

Stanley Kubrick's seminal satire on the Cold War features multiple unforgettable performances from comedy icon Peter Sellers. But George C. Scott's portrayal of the snarling General Buck Turgidson is just as amazing, perhaps most in the scene where he trips and falls in the War Room and then smoothly gets up as if it didn't happen.

Well, that fall wasn't improvised; it was a complete accident. And even though Kubrick is known for his exacting filmmaking style, the fall fit the tone so well that it stayed in the picture.

Comedian Whoopi Goldberg portrayed medium Oda Mae Brown in the classic supernatural romance "Ghost," but director Jerry Zucker was initially concerned with bringing her on, worrying her natural comedic aura might ruin the film's tragic tone. Yet she did the opposite, delivering a career-defining performance and an improvised line of dialogue that everyone who's seen the film can't forget.

When the ghost of Sam (Patrick Swayze) attempts to convey—through Oda—to his lost love, Molly (Demi Moore), the same threat that killed him, the script called for Goldberg to tell Molly, "He's saying you're in danger." Instead, Goldberg said, "Molly, you in danger, girl," and it couldn't have captured her character more perfectly.

After its debut in the first film, "Yippee-ki-yay, motherf-----!" has become the defining battle cry of Bruce Willis' unlikely hero John McClane of the "Die Hard" franchise. However, "Die Hard" screenwriter Steven E. de Souza revealed in a Radio Times interview that the original line was actually "Yippee-ki-yay, a--hole!" in the scene where McClane speaks to antagonist Hans Gruber (Alan Rickman) over their walkie-talkies. Or at least de Souza is pretty sure he never wrote "motherf-----," crediting it instead to Willis' suggestion.

Story editing by Cynthia Rebolledo. Copy editing by Paris Close. Photo selection by Clarese Moller.