Unless you’re writing the type of artistic film where you only show time lapses of moss growing or something, you’re likely going to need characters to populate your script. They may be a hodgepodge group of high schoolers or even anthropomorphic cars.


The most important of which is your main character. And they should do more than just go through the motions.
Your main character needs to be interesting. Infuse them with details, quirks, dialogue that makes the reader, and eventually audience, enjoy going on this ride with them.
How do you do this? Start thinking details. Are they funny? Smart in a really unique way? Do they see the world in a way others do not? Do they have a personal struggle and you can’t help but root for them?
Do they have a general disdain for humanity but also the propensity for curing everyone’s ills?

You want to avoid stereotypes in your main character. Instead of having a genius doctor, you have a genius doctor who lacks a bedside manner, has a physical disability which leads him to a dependency on narcotics.
So let’s talk round vs flat characters.
“A round character is deep and layered character in a story. Round characters are interesting to audiences because they feel like real people; audiences often feel invested in these characters’ goals, successes, failures, strengths, and weaknesses.”
https://www.masterclass.com/articles/round-vs-flat-characters-in-fiction
Round characters are more interesting and make your reader and audience more invested in the story.
“A flat character is a two-dimensional character lacking depth or a real personality. Usually, flat characters have just one or two perfunctory traits. Often considered “stock characters,” flat characters can often be summarized in one word (like “bully” or “love interest”) and never digress from or transcend their role.”
https://www.masterclass.com/articles/round-vs-flat-characters-in-fiction
A flat character lacks the great detail that makes a compelling character. They fall into stereotypes — the distracted professor, the overworked single mom, the ditsy cheerleader… we’ve seen these time and again. It’s fine if they populate the rest of your world a bit, but for the characters we follow? We want more.
How to write a round character:
- Character Traits. What are their character traits, both good and bad? What is the flaw your main character possesses that might cause them grief later in the story?
- Details. What are their likes/dislikes? What is their appearance? What sports do they play? Where do they work? You might not use all of these, but it will help you make more informed decisions on how your character will act.
- Believability. Your main character has believable reactions to events based on their character traits. A generally mellow person won’t just blow up at a minor inconvenience. It wouldn’t fit their character. Don’t lose your reader, and later your audience, by making your character behave strangely.
- Conflict. Give them an internal and external conflict. The main conflict may be the fate of the world ending, but the internal conflict may be a father regaining the love of his estranged daughter.
- Dialogue. Your character has a voice, and it should be a distinct voice. If you cover up the names of all the characters in your script and read the dialogue, you should be able to tell who is speaking. Don’t let everyone sound the same.
Building a really interesting main character is one part of writing that great first script.
Sources:
https://blog.reedsy.com/round-character/
https://www.masterclass.com/articles/round-vs-flat-characters-in-fiction