“Use the time of a total stranger in such a way that he or she will not feel the time was wasted.”
On first blush, this seems very general and very obvious. Of course, people who read your screenplay or eventually see your movie want to feel that the time they’ve spent with your story has been worthwhile. The audience should feel that they’ve learned something, felt something (joy or fear or loss or longing and always some sense of satisfaction) and have been transported for a brief amount of time to another world.
But this maxim can also be applied specifically to the art of screenwriting. “Why are we watching this story, now?” If you cannot answer that question with conviction, you need to rethink the story you are trying to tell. A well-constructed script doesn’t begin a moment before or after it absolutely has to begin. Usually (but not always) a screenplay opens with a protagonist who has a need and an event occurs (inciting incident) that endangers that need. The need may be obvious before the inciting incident, or it may be revealed over time. Jake in CHINATOWN has a need to atone for a case gone wrong in his past; the Mulwray case gives him an opportunity to do that – or fail. The script starts with Jake telling a broken-down client that his wife his having an affair. He’s a PI, not particularly high class. Moments later Jake is hired by the fake Evelyn Mulrway (with only a character beat of a dirty joke to establish Jake as a rapscallion and someone who sometimes acts before he thinks.) In ORDINARY PEOPLE – a tricky case because it’s debatable who the real protagonist is – Conrad has just come home from the hospital after a suicide attempt. The first sequence shows scenes from a happy, normal family – son at choir practice, affluent parents out for an evening. The only hint that not all is well is dad asks Conrad if he’s called a doctor. The sequence ends with breakfast the next day at home – a dynamic scene between Conrad his mother and father. When his mother dumps his breakfast in the trash, the question is will he survive? (Other people say Conrad’s father is the true protagonist – the inciting incident is Conrad coming home from the hospital and his father’s need is to have a happy, stable family again.)
The same precision should apply to each and every scene in your screenplay. The rule of thumb is a scene should start as late as possible and end as soon as possible. Every bit of dialogue, every action needs to be purposeful and have a reason. The reader/viewer wants to be guided by a masterful hand. If two characters have a chat about the lake house in act one – the script better travel to the lake house by act three. (Or a body needs to be discovered there – take your pick.) In screenplays there is no such thing as small talk.
Be ruthless with your work (not necessarily in the first draft.) Look at every line of dialogue, every description – is it necessary to tell your story? If not, you probably don’t need it.