A protagonist is the main character in a novel or story that all the action revolves around. They are the hero of the story, the one we are rooting for from beginning to end. We follow their life, learn about their problems, and know their feelings and thoughts.
A protagonist needs a weakness. Even Superman, known as the Man of Steel, had a weakness, which was Kryptonite. This weakness can be anything from something that physically makes them weak to an event from their past that had put fear in them.
In my series, my main character has supernatural powers and a form of Kryptonite that hurts her. She also has many scars from her past that resurfaces during the course of the series.
A protagonist also loves. In every book, from every genre, the protagonist loves. If they don’t actually fall in love then they should show love. Another emotion a protagonist must reveal, at least once throughout the whole story, is fear. Fear is the most common emotion; it makes us human, and as I’ve mentioned before you need to make your characters as real as possible. (See: Blog #19 Characters Make A Book) Even my main character, that is known to be fearless, experiences fear in each novel.
Most of all, a protagonist must struggle. Life is all about struggle. There needs to be conflict that the protagonist has to overcome whether it is beating cancer, putting a crumbling marriage back together, finding true love, or saving the world.
For tips on how to create a "good" antagonist go to: http://writewithfey.blogspot.com/2012/08/protagonist-vs-antagonist.html
Blog #19 Characters Make A Book: http://writewithfey.blogspot.com/2012/05/characters-make-book.html