Not every moment of movie genius is written down in the script.

Take this collection of ad-libs and off-script moments, for instance…

Here are 10 examples of when an ad-lib or off-script moment went very, very right…

Taxi Driver: You talkin to me?

In the original script Schrader had simply written Bickle speaks to himself in the mirror.

Alone in his grubby apartment, De Niros loner sociopath character Travis Bickle is planning to shoot a politician.

In the mirror he is practising with the sleeve-holster he made for his gun.

Catching his reflection, he postures, repeating You talkin to me?

before whipping out his gun and taking aim.

The Shining Heeeeeeres Johnny!

Kubrick would scream and shout at her, and allegedly even slapped her across the face during one take.

Harrison Ford, playing our protagonist explorer Indie Jones, got a bad case of food poisoning and dysentery.

He was due to shoot a big fight scene with a skilled swordsman the next day.

And off-script movie magic is made.

The screenplay was based on the Philip K. Dick novelDo Androids Dream Of Electric Sheep?.

Hollywood legend has it that Martin Scorsese was originally interested in the adaptation but never optioned it.

That would have been interesting.

But we all love Scotts dark, moody, original and highly influential shoot which launched a thousand mimics.

And we especially love the Aryan, cold, violent Roy Batty, the perfect replicant (android).

Played fantastically by Rutger Hauer, Batty is LAPD Officer Deckards nemesis.

Ive seen things you people wouldnt believe.

Attack ships on fire off the shoulder of Orion.

I watched C-beams glitter in the dark near the Tannhauser gate.

All those moments will be lost in time.

Like tears in the rain.

Mad to thinkBladerunneris set in 2019.

Doubt well have such perfect androids in only ten years time.

Hes explaining that to make omelettes you gotta break eggs.

Illustrating Welles absolute cinematic brilliance, he includes the cuckoo line.

They produced Michelangelo, Leonardo da Vinci, and the Renaissance.

In Switzerland they had brotherly love, five hundred years of democracy and peace.

And what did that produce?

Midnight Cowboy: Im walkin here!

(John Schlesinger, 1969)

Okay, its been disputed as to whether this was off-script or not.

But its not past the methodical Dustin Hoffman to ad-lib such a brilliant line.

Hoffman beats the hood with his fist and shouts, Im walkin here!

is often cited as one of the worlds best movie quotes.

Its usually thought of as an improvised line, which Hoffman has claimed.

And he is certainly more than capable of this kind of fleshed-out character portrayal.

But producer Jermoe Hellman has always maintained that it was in the script.

Strangelovewere improvised that he is often cited as an uncredited co-writer.

And it is considered a study of retro-scripting, ie.

when ad-libbed lines are later written into the final script.

Dr. Strangelove is a wheelchair-bound German nuclear weapons expert, who has a past association with the Nazis.

This was entirely Sellers creation.

The word genius does get thrown around but, good lord, Peter Sellers really deserves the moniker.

Goodfellas: Funny how?

With relief, might I add.

It exemplifies beautifully how crazy Pescis character is.

Although he only has under twenty-five minutes of screen time, Hopkins won an Oscar for Best Actor.

All in a days work.

I ate his liver with some fava beans and a nice Chianti.

Hollywood rumour says that this hissing was just a joke thrown in by Hopkins.

Casablanca: Heres looking at you, kid.

(Michael Curtiz, 1942)

Ah,Casablanca.

What can we say?

Then, to our ad-libbed moment.

Crying, she tries to convince him to let her stay.

The American Film Institute often calls it one of the most memorable lines in film.

It is often quoted and parodied.

It was never in the original script at all.

Hes won Academy Awards for screenplays by dong this.

And it shows, as his work is some of the most interesting and authentic in cinema today.

Notable movies includeNaked,Happy Go Lucky,Vera DrakeandSecrets & Lies.

Christopher Guest works his movie scripts much like Larry David does forCurb Your Enthusiasm.