Was skimming through the blog of an author I recently read, Wen Spencer. She has a few posts about the story telling process.
She had the useful definition of Act 1 being about introducing the main players and problems. The transition from Act 1 to 2 is when the main characters change from being reactive to being proactive (so not just getting bounced around, they make a plan). Act 2 you can introduce new problems or characters, but they shouldn't be major ones. Act 3 is about tying up the threads, no new stuff, this is the act where you have the big showdown, and then let the readers bask in the after glow for a while (let the readers enjoy a taste of the happily ever after they've earned with the characters).
Another interesting idea (to me at least) was knowing your acts by word count (which works minute wise in film). So her books are 100,000 words long, so each act is 33,000 words. Each scene is about 1000-2000 words. So she only has 15-30 scenes to set up her main characters, introduce the problem, and get the team together enough to make a plan and get to work. So when you break it down that way, each character really only has a handful of scenes for us to get to know them, there's not really time for not getting right to the point.
*All these "write a screenplay" books basically point back to Aristotle and 3 Act structure, taking it for granted that that's the way to write a story (and admittedly it can make very strong stories). But I am really curious about what other cultures take for granted as the basic building blocks and essential parts of making a story, if any one reading this has any insight please chime in :)
*think I need to split up the story and character label, though they are pretty integral to each other