A “beat sheet” is a form of an outline. In this form, you can think of each beat as an individual unit of plot, so a beat sheet in an outline that’s specific purpose is to touch on each of those. (John August’s screenwriting.io).

Note that beat sheets are also commonly written after there is a draft of a screenplay. I’ve asked my assistants to do a beat sheet of a script I’m about to begin rewriting so that I’ll have a roadmap of how things are arranged. (JohnAugust.com)

You’ll find I talk a lot about “forty beats” in the pages of this blog, and when I say that I’m really talking about a beat sheet. A beat sheet is just a list of what happens in the story. It can be written after the fact, as a precis of what’s in the draft, or it can be written in the development process as you try to flesh out your story.

A beat sheet is an agnostic tool. A lot of writing “gurus” like to map out the beats according to their personal theories on how stories are told. Take these with a grain of salt, when talking with another writer or producer never try to impose conflate the concept of beats with a theory on how they should be used, it just leads to an argument.

So in brief, a beat sheet is an inventory of the key moments that exist in your script. They are commonly used after the script is written.

There are ways to create a beat sheet before you write your screenplay (most approaches that use index cards on a board create a de facto beat sheet that’s intended to help develop the outline and facilitate the writing of the first draft).

As an exercise, I like to have my clients test their story ideas in beat sheet form before they start writing. This is a good test to see if you have enough content to fill 100 pages. This is also the hardest exercise I’ve ever come up with, so hard that 90% of people get discouraged while doing it (when something’s that hard, it’s the fault of the dumb teacher who inadequately explained the exercise, me, than the people).

With that said, I’d like to break down the exercise a little more in my next blog post, in the hopes of making it easier and more useful. When done right, it’s a powerful development tool.