I just read The Writer's Journey which has some pretty good stuff. It takes The Hero with a Thousand Faces and makes it more accessible and practical for modern screenwriting. It's different from other screenwriting books in that it details character archetypes (which were more or less useful). I've started to realize how often the mentor archetype gives a gift to the protagonist for him or her to use later. It's how James Bond gets all his cool shit!

I've found Snyder's 15 beats in his book Save the Cat to be incredibly useful as a more detailed and practical breakdown of the 3-act structure. A simple list of the beats is available on his site, but obviously for more in-depth descriptions of the beats and how they work, you'll have to buy the book.

http://www.blakesnyder.com/tools/

There is something to it.

Still for me a slavish 3 act structure with a time diagram a la Syd Field is the end of true art. It makes a movie a mathematic theorem. You cant push or press emotions in a corsett like that. A good story develops its own life, makes its own choices and decides how much room it needs.

Something like @shian 's diagram can in my opinion only be a first orientation if you are totally new to dramaturgy.

Luis Bunuel once invented a script machine (it was an ironic idea of him) to write movie stories just following those structures. A terrible caricature of a lot of Hollywood work. Like a machine without soul. This can of course work. Hollywood has worked on those standards for decades. The audience wants the same boring story told 1000 times, 10 years ago it was Jennifer Aniston, now its Mila Kundis who is the audiences darling for those roles. But no Bergman, Bunuel, Kurosawa, Bresson, Tarkovksy etc etc would work like that.

You dont have to be as drastic as Tarkovsky, abandoning classic dramaturgy and saying a poetic structure is the closest to life. But i think many of his ideas are true.

I read a book once that is based on Joseph Campbells theories. http://www.amazon.com/Soul-Screenwriting-Writing-Dramatic-Yourself/dp/082642869X

Its a nice book. Still, Hollywood has also used those structures for almost 4 decades now, especially after their success in Star Wars. After that everybody tried to make scripts like that, hoping to emulate the sucess.

In my opinion those structures are just a small assistance when you get stuck in the developement of a story.

I said that if you stick by it slavish it kills everything and i admitted it works for some :) I just think its wrong to asume that once you follow these steps you get a good story :)

@shian: thats just partly true. I was working at a tv station that was producing or co-producing some of europes biggest arthouse cinema, for example the d'ardenne brothers who won in Cannes. We got like 10-20 scripts or exposees a day. Not all scripts were in 3 acts in a slavish manner.

Also, watch movies like tarkovskys "mirror" or bunuels phantom of the opera, kurosawas "rashomon", you wont find 3acts...

but i agree 90% of the movies are made after the 3 act principle...but the basic original principle of story telling is closer to the heros journey by campbell than the 3 acts principle.

And its also true, the more established you are, the more creative freedom you are granted. But if you write a super duper script that has nothing to do with 3 act structure it will get produced. A good reel or filmography certainly makes a lot of things easier. I saw someone like Christian Petzold who won the Berlinale this year just had to reach in a 2 paper rough cut or sketch and his stuff was produced...