The protagonist’s problem

A story is about a problem. Your protagonist is the one experiencing the problem. Why? Because you, the writer, has designed him for it. The bigger the problem is, the bigger the person has to be, to be capable of resolving it. That’s why only your protagonist can resolve your story-worthy problem.

The 7 Phases of Character Transformation

Martha Beck (life coach) wrote a book (The Four Day Win, 2007) and dug into the world of science and looked into data from social sciences to discover the process people go through when changing their lives. She uncovered the Transtheoretical Mode of Change, which is pretty damn handy when writing a book, to make sure you have believable character transformation.