It doesn't matter if a story IS true; it must SEEM true

Occasionally during my days at MZB's we would reject a story and get back a letter complaining, "But the story is true!"

Marion's rejoinder was always that it mattered not a whit if the story WAS true, it had to SEEM true to a reader.

This requires walking a fine line between oblivion and defensiveness. Picking a believable tone is important; there's no need to sound stuffy and academic, but your narrator must appear to be credible (or if not, this must be deliberate -- for instance you can create a pretty interesting story if you tell the same incident from three points of view, two of whom are the same narrator under different circumstances; in one of the circumstances, the narrator must appear to be explaining why he has lied in the other circumstance).

If your story is flat-out fantasy, you need to put in enough plausible details to bolster the illusion so that your reader can suspend disbelief enough to enjoy your tale.

-- Rachel Holmen