It is what we need to see in order for the story to move forward. It is a moment of drama or comedy 鈥� of action, of import, of change.
Scenes in which things are just explained or related are not scenes 鈥� they are exposition, because nothing really happens. In scenes, something significant must happen 鈥� however cataclysmic, or however tiny and subtle.
So ask yourself 鈥� in what way is the scene moving the story forward? What purpose does it have in the story, and in the drama or comedy? If you can鈥檛 answer either question, then does it need to be there?
Scenes show the conflicts and tensions, dilemmas and decisions, actions and reactions, of the characters driving your story. But they aren鈥檛 only about what can be shown explicitly. Great scriptwriting has subtext 鈥� things going on, things playing out, silent conversations being had, that exist below the surface and beyond what is being 鈥榮aid鈥�.
Ask yourself these questions of every scene you plan to write:
1. What effect does this scene have on the character within the moment?
2. What effect does it have on the subsequent events of the story?
3. What impact does it have on the world of the story?
4. What else is going on below the surface and beyond the text?
Scenes aren鈥檛 just about themselves in isolation. Juxtaposition is crucial. Where it is placed in a sequence of events can define what a scene does and means, and how well it works. So what comes before? What comes after? Do they have a related effect on a sequence of events? If not, do they have an effect on how the audience sees and makes sense of the events?
Different kinds of scenes can come at different points in the story 鈥� if all your scenes look and sound and feel and seem similar, then the story will be dull. Each scene needs a specific and unique purpose in the story. Work that out, and you鈥檒l save a lot of wasted time recapping the story and treading water as you go.
