I already see things in my post I wish I had qualified. For example, an argument can be made that Nurse Ratched isn't really the antagonist in "Cuckoo's Nest"; that it's actually McMurphy, and that Chief Bromden is the protagonist. I've usually leaned towards the view that McMurphy is a protagonist who "refuses to change" and dies at the end. Some teachers will tell you that "death is not a change" (a blunt way of warning screenwriters not to kill their protagonists) but I don't know if that rule applies in the case of a movie about a protagonist who "refuses to change". (i.e. "Mishima" ends with a suicide--but I digress.)

It's a lot of fun to think about these things.

But I always hesitate to make concrete assertions about such matters!

Good luck with your writing. Writing for stage must be fascinating. I'm guessing you can really focus on casting a spell over the audience because you can spend more time in one place, and are not constantly interrupted by scene changes. Just watching characters interact over a longer period of time can be so interesting.

(It's a movie, but I'm thinking of how thrilling something like "My Dinner with Andre" was in spite of it just being two people talking for more than ninety minutes. I also recall being riveted by the film of the play "Carnage", and I like Mamet's early plays.)

Would love to know more about stage writing.