The idea that every character in a script has to have an arc is a screenwriting canard that needs to die. Would you want Spiderman’s Aunt Mae to change drastically? What purpose would it serve for Madea to tone down her act?
We can delight in characters who don’t change as long as they are dramatically active and they have compelling personas.
Being dramatically active means they are essential to understanding the fictional world. Their insights and point of view make the world shimmer. They can serve as a critical fulcrum for the dueling ideas in your script.
Where did this pressure come from? Actors. It can feel more interesting to play a character who changes drastically. It feels like “acting.” Producers who have read the gurus who harp on character arcs.
Thinking through the relationship between story and character arcs is the essence of craft. Which characters will change? To what degree? And the all important, why?