When asked to define character arc, most people think it has something to do with how the Main Character changes within a story. While in some respect this is correct, it is inaccurate to assume that this means every Main Character needs to undergo some major transformation. Understanding the difference between growth and change is essential to the proper implementation of character arc in a story.
Without a doubt, Main Characters need to grow. A story cannot develop organically if the principal characters within it do not grow and adapt to the shifting dramatic tides. When an act progresses from one area of exploration to the next, the Main Character needs to progress as well. That’s how stories work. Therefore, it is easy to see how growth, and in particular the Main Character’s growth, is inherent in the mechanisms that run story.