on Writers Helping Writers:

How to handle a character’s backstory is a universal struggle for all of us writers. How much should we include? How long should a flashback be? When is it okay to give a character’s backstory? Is backstory even necessary?

As an editor, I’ve seen it all. Books that start with a long flashback, books that don’t provide the reader enough footing in a character’s past, and books that nail the balance of keeping the front story moving while sprinkling in backstory.

First, the undeniable truth: Whether we like it or not, backstory is necessary. Otherwise, that inherent feeling that your character needs whatever you have planned in the front story isn’t there, spurning your reader on to find out if this story will help them be okay. Backstory is the battery pack that fuels your novel, giving it purpose.

The good news is that you only need to develop that which is relevant to whatever made the character not okay in the first place.