Ever read a bestselling novel in which the hero was a construction worker?
It's a story-telling basic that writers – even published authors – tend to forget. It's the reason Stephen King's characters tend to be novelists. It's the reason we haven't seen Khaled Hosseini stray too far from the Middle East. Or Jeffrey Eugenides from Detroit. And it's the reason bestselling authors rarely deviate from their chosen genre.
Write what you know.
It's almost silly how often I see a proposal come through from a published author who suddenly wants to take a stab at writing for teens. Or African Americans. Or the thriller/adventure crowd. And yet that author has done nothing to understand the basics (let alone the complexities) that surround their new target market.
And if we're seeing this from published authors, imagine the type of stuff we see from unpublished ones.
The goal of a novel, however off-the-wall or hokey the plot may be, is to get the reader's buy-in. With it, the reader is able to fully immerse themselves in the story and, to some extent, believe in what's happening. Without it, the reader spends his time picking it apart, analyzing the details and scoffing at its overall ridiculousness.
This is because when authors write outside of their expertise, the sense of reality that should surround their story starts to deteriorate. Readers begin to notice inconsistencies and begin to question whether the author has ever even seen the Eiffel Tower or heard an M-16 fire or ridden on Chicago's 'L'.
A story can only be as good as the reality behind it, you see, and readers tend to be extremely educated in their genre-of-choice.
So, if you're a homemaker, living in a suburb of Cleveland with field experience in Nursing and a few Horse Jumping trophies in your closet, it's probably not a good idea to come to us with your idea for a nuclear warfare novel that takes an ex-Marine and a young Mediterranean fisherman and turns them into Israeli diplomats (not to mention best friends, of course).
Unless you've done a lot of research.