[excerpted from my current post on “Do You Know Where YOUR Story Is?]

• I don’t care if all the inhabitants of a planet are legless, have a single blue eye, gills, and live in a tank where they are dependent on water, melons, and cress to live. Just don’t suddenly have their out-of-town cousin travel in on the next train walking on three legs, smoking a cigar, and using four eyes to watch me out of the back of their head. It doesn’t fit the world you built.

• Writing romance? I know, love at first sight. But meeting a mysterious stranger, marrying them on the same page and going off to live in Saigon when you’re a celibate rocket scientist in the midst of a critical development is not going to work. That scientist, upon the entrance of the stranger, would more logically say, “Get out of my lab, I’m busy. Security!” If that romance is going to happen, it won’t be the way the writer wrote it the first time.

• Time travel; it’s tricky. There are various types of time travel, and you have to decide what rules yours is going to follow. Does the traveler control the travel? Do they remember their own time? Can they get back? And the all-important: will anything they do in the past affect the future they left behind? Whatever rules you choose, you have to work consistently within them or readers will call foul. I certainly will.

• Just as bad—not playing fair with the reader in a mystery. Mystery lovers want to solve the mystery along with the detective. Not letting them have the same clues the detective does isn’t fair. It’s fine if the detective doesn’t reveal what they’ve concluded from the clues—after all, you want that big reveal at the end. But you can’t hide the actual clues from the reader. (Although you can make them obscure.)

I’ve probably driven writers crazy harping on this, but it bears repeating.