Scenes can come in all shapes and sizes: a one-sentence establishing, a half-page aftermath, a three-page reversal, the list goes on. And clearly there’s a lot that goes into crafting a great scene: start late; get out early; maintain conflict; keep lines of dialogue brief; keep action paragraphs short; maximize white space; avoid “I” and block pages; incorporate subtext and indirection; create audience connection through suspense, mystery, and revelation; and show the story in a visually interesting way, all while writing with a unique original voice. But that’s all execution.
Screenplays are built on “What happens next?” and, therefore, the root of every scene comes down to two fundamental objectives: (1) moving the story forward and/or (2) revealing character. The very best scenes do both.
But here’s the hard part, and something I call the 100% rule: if you’re not 100% positive that at least one of these two scene objectives is necessary, you must absolutely kill it! Even if you love it, even if it’s funny, or witty, or clever, if it doesn’t move the story forward or reveal some essential complexity of character, you simply do not need it.