When a reader picks up your tale, you want them to become invested. When you pick up a book, don’t you yourself want to relate in some way to what you are reading? Doing so helps one better understand the story. The thrill of the action, the twists, and the potential romance or heartbreak will hit harder, when the reader is invested. The best way to do so, is with the protagonist.
1) Do you care? Perhaps the protagonist doesn’t need to be the most likeable character of the story. But in my opinion, being able to root for the protagonist, makes the story worthwhile. There are goals that need to be achieved, and you read and experience the pressure, the frustration, the hope, and desires to reach those goals, alongside the protagonist.
2)Identity: What are the traits that make up your protagonist? That includes it’s backstory, because every full, rounded, character needs a back story. They were not dropped into their situation, they don’t make choices based on nothing. Who they are, and how they act throughout the story should reflect their backstory, as our own pasts influence our own decisions in life. Identity adds life and realism, which in turn helps the reader relate and invest in the character.
The characters you love, are the ones that remain in your mind, long after the last page of the book is read.