I started entertainment life as a Director in English Rep, with a regular company doing different plays every one, two, or three weeks. The actors needed to be (and were) versatile and wonderful-so I entirely disapprove of this whole chapter.
It is here because, alas, I know it to be all too true!
Suppose that you went out to the movies right now. As you buy your ticket, you look at the poster in the foyer, and you recognize all the names of the stars in the film you are about to see.
How many of those performances can you predict before you see the movie? Most of them? All of them?
You see, I have not told you if the movie is modern or set in ancient times; whether it is a mystery or a comedy; whether it is set in Paris or outer space; if it was written by a genius or a hack. Yet you know the performances (or most of them) by knowing the names of the actors.
This is what is known as typecasting.
Imagine a scene in a movie where the doorbell rings, the hero goes to open it, and there is the pizza delivery person, who says, "Here is the pizza you ordered." Imagine that the part is played by you. What will be the effect in the movie of you saying that line?
You might well reply that it depends on what you are acting, what you are portraying, what thoughts/emotions/memories are in your head. But you would be wrong.