Recently, spoofs of John Travolta's famous movie lines went viral, after the actor fumbled while introducing the performance of Idina Menzel at this year's Academy Awards. Following the name flub, parody articles popped up overnight, making fun of some of the classic dialogues by Travolta. 

A film's story is always a definite plan. It is written and finalized months before the actual filming. The script goes through an entire army of professionals from writers, directors, producers to studio officials.

But some of the most memorable scenes in cinema have been created on-the-spot. Talented actors and actresses have been known to break into impromptu lines, gestures and monologues on different occasions.

Let's take a look at some of the most iconic scenes that were unscripted and were never supposed to be a part the film.

Pretty Woman (1990) - The scene where Edward Lewis (Richard Gere) presents a glittering and rather expensive diamond necklace to Vivian Ward (Julia Roberts) went on to became a famous one. As Roberts reaches out to touch the necklace, Gere - in a spur of the moment - shuts the box and leaves Roberts surprised. As a reaction to that, Roberts came out with an endearing and honest laugh. Director Garry Marshall was so impressed with the scene that he decided to include it in the film as it is.

Saving Private Ryan (1998)- While waiting for the German assault, Captain John H Miller (Tom Hanks) takes a break and sits down with Private James Francis Ryan (Matt Damon) on French Street. They both get talking about their families and exchange stories about what is it like at home. When Ryan asks Miller to tell him about his wife, Miller refuses, saying that memory is for him alone. But the story that Ryan clearly remembers of his brothers and how they burned down the barn was spontaneously made up by him at that moment. The details about his family background were never a part of the script.

Good Will Hunting (1997) - During one of Will Hunting's therapy sessions, his therapist Sean Maguire (Robin Williams) tells him a personal story to make Hunting (Matt Damon) open up to him easily. He tells a story about his flatulent wife to which Damon laughs hysterically. His genuine laugh can be easily spotted in the scene. This story was made up by Williams on the spot. So much so, that the story even cracked up the cameraman. If you look closely, the camera can be seen shaking a tiny bit in the scene. Williams was nominated for Best Supporting Actor and won his only Oscar for his spectacular performance as the therapist in Good Will Hunting.

Reservoir Dogs (1992) - In one particular scene from the film, a cop is seen tied up, has his mouth taped. Vic Vega (Michael Madsen) is torturing him. The song "Stuck in the Middle With You" starts playing in the background and Madsen breaks into a jig. He then goes near the cop and chops off his ear with a razor. Director Quentin Tarantino did not have any dialogue or gesture for him after cutting off the cop's ear but Madsen improvised on the spot, held up the bleeding ear and talked into it: "Hey, what's going on? You hear that?"

Casablanca (1942) - The one line that everyone recalls as soon as this epic film is brought up is Rick Blaine's "Here's looking at you kid". This famous dialogue by Humphrey Bogart was improvised by him on the set itself. It was never a part of the original script and later became one of the most iconic lines in cinema history.

The Godfather (1972) - Just when Peter Clemeza (Richard Castellano) is stepping out to have Paulie Gatto killed, his wife tells him to pick up some cannoli on his way back. After Clemenza's goons handle Gatto in a parked car, he instructs them: "Leave the gun, take the cannoli". The dialogue as per the script was just "Leave the gun" but Castellano decided to add some impromptu humor to the scene and came out with a memorable line, with just a little tweaking.