Some of the best, most iconic scenes in cinematic history are improvised. Actors are fluid, much to the writers dismay, and they sometimes go off script or throw in an extra line that wasn't meant to be there. Usually these accidents call for a re-shooting of the scenes, but in some cases the director loves it and these scenes become the most memorable of the whole film. Check out these top 10 unscripted scenes and you might be shocked to find that your favorite movie moment was never actually planned.

1. Blade Runner-1982

Blade Runner

The most famous adaption of a Stephen King novel, The Shining, has scared generation after generation with it's creepy twists and its insane characters. Jack Torrance, played by Jack Nicholson, is a writer who moves his family into a shut down hotel for the winter. Slowly, Jack starts to go crazy and in the most famous scene of the film, he tears down the bathroom door with an axe and yells "Here's Johnny!" as he sticks his head through. That iconic line was improvised by Jack Nicholson (inspired by the Tonight Show starring Johnny Carson).

6. Pretty Woman-1990

In this light-hearted romcom starring Julia Roberts and Richard Gere, there's a cute scene where Edward (Gere's character) is giving Vivian (Roberts' character) a gift of an expensive and beautiful necklace. But as Vivian reaches for it, Edward closes the lid of the box snapping Vivian's fingers making her laugh. That whole incident was not scripted, Gere just wanted to surprise Roberts and Roberts' reaction was caught on screen.

7. Jaws-1975

Jaws is a classic "scary" film everyone has seen at least once. With the giant animated shark terrorizing the oceans, what's not to love? When Police Chief Brody and Captain Quint finally get a good look at the killer shark, Captain Quint utters the most famous line from the whole franchise, "You're going to need a bigger boat." This line was not scripted, Robert Shaw (who played Quint) went completely off script and the directors kept the line in.

8. The Godfather-1972

This epic film follows a mafia family in the 40s who are trying to protect their legacy from rival families as there is a power switch from father to son. In the adorable violent scene where Vito Corleone (Marlon Brando) is ordering someones death while petting a cat. The cat was unscripted and there is a bit of mystery of where it came from. Some claim that the director, Coppola, gave Brando the cat right before filming the scene. Others say that Brando just found the cat wandering around set and picked it up and brought it with him during the scene.

9.The Silence of the Lambs-1991

The famous "hsssss" that Dr. Hannibal Lector (Anthony Hopkins) makes during his story of eating liver with beans which he recounts to FBI agent Clarice Starling (Jodi Foster) is completely unscripted. Hopkins used the hssss noise to freak out Foster for fun, but the director found that it was so in character that they kept it in the scene.

10. The Dark Knight-2008

In Heath Ledger's creepiest role, The Joker, Ledger really got into his method acting, so much that even some cast members were afraid of him. A lot of Ledgers scenes in The Dark Knight were improvised. One scene, were we see the Joker locked up in jail, there is a promotion going on within the police force. As there is a huge applause for the one who just got promoted, the Joker starts clapping as well, never changing his facial expression. It's an creepy scene and the director found it to be so in character they kept it in. There was also the scene where he blows up a hospital and is fidgeting with the remote control. That whole scene was also unscripted, but Ledger took the opportunity to create more of his character.