From the awesome source, Lee Lefever and Common Craft:


Simply put, writing a script has power. We recommend writing as if you’re writing a script for a three minute video – about 500 words. Whether you actually produce a video or not, this exercise will help you see your messaging in a new light.

We’ve provided points below that will walk you through the process of writing a script for YVOC video that has one big goal: understanding.

How an Idea Becomes a Script

You’ve probably seen the TV series South Park. Have you ever wondered where the magic happens? What is the secret to making South Park so entertaining? Hint: It’s the script.  Before the cameras roll or the computers start, serious work goes into thinking through the story and writing down what the characters will say. Your YVOC video is no different.
Of course, you can’t just dive into the script for an explainer video.  First you must consider a few major points:

  • Who is the audience and what do they need to understand?
  • What two or three key points can We communicate that will serve that need?
  • What do we want my audience to do once they understand?
Having thought through these points, it’s time to start writing. Start by getting ideas on the page. In your mind’s eye, picture a person you know who is similar to your target audience. What kind of language would they understand, and what would resonate with them? Put yourself in their shoes. Empathize.

Why and How

Most explainer videos answer two central questions: “why?” and “how?”
You’ll want to start with “why?” so that you can answer these kinds of questions for the viewer:
  • Why should We care?
  • Why does this product or service make sense?
  • Why does it matter to me?
By focusing on the question of “why?”, we will offer the audience a reason to stay engaged.
Next up is “how?” This is how something works, or how one goes about completing a task. The right balance of why and how delivers understanding. For now don’t worry too much about visuals. Make note of visual ideas, but keep focused on the script. We’ll get to visuals soon.

Explanation Stepping Stones

Explanation

As we mentioned, research shows that simply writing down an explanation helps you understand it better, so take time to write down the big points you want to make. When you do, consider the points below as a framework for your script. We provide them not as a template or step-by-step process, but a guide.
1. Build context.  Before diving into the details, set the scene for the world where your ideas live. Talk about the forest before the trees and you’ll build a solid foundation. In other words, show the audience why the idea matters first.
2.  Tell stories. Many of our explainer videos use a very simple formula: Meet Bob, he’s like you. Bob has a problem, he feels bad. Look! Bob found a solution and now he feels great. Don’t you want to feel like Bob? Your job is to help the audience see themselves in Bob.
3. Make connections. Look for opportunities to build on the audience’s existing knowledge. Use an example they already understand to introduce a new idea. For instance, here’s a very simple example for someone who’s never seen a boat: It’s like a car, but on water. Analogy can be powerful. Provide a foundation that they understand and build on it slowly.
4. Describe the steps and why they matter. If you’re explaining how to do something, keep it high-level, and limited to a few memorable steps. Explainer videos should focus less on documentation or discussing detailed processes, and more on motivating the audience to see the big ideas and why they make sense. Your goal is to inspire them so that they’ll want to learn the details later.
5. Call to action. Your video probably has a goal in mind. Now that your audience understands the main idea, what’s next? Can they learn more at a website? Can they download an app? Can they share the video? An explainer video is often a means to an end; be sure to show your audience the next step and encourage them to take it.
A note on length:  As a general rule, you’ll want to keep your explainer video short, usually under three minutes. The script is your first chance to work on length and you can do that with word count. At Common Craft, our rule of thumb is about 160 words per minute of voice-over time. Our goal is to write scripts of 400-500 words. Your mileage may vary.
The beauty of the scripting phase is that it’s cheap and easy to share and change. Iterate and ask for feedback.  Read it aloud. The script is the secret sauce of explainer videos, treat it with care.
We’ve provided this framework as a starting point. Every audience, situation and video is different and it’s up to you to create an explainer script that works for your audience.