Suspension of Disbelief (part 3)

I've often asserted that it is much more difficult to write sci-fi than fantasy because it is so much more reality-based. With fantasy, the writer can create the very laws of his universe, but a sci-fi writer cannot stray too far from reality without offering clear, reasonable explanations for doing so. However, with both genres, one simple concept undergirds everything the author writes—once he has established the “rules,” he cannot violate them without a warning and adequate explanation. While small violations can be overlooked by some, they may still remove the audience from the experience enough that they will not give a positive rating to the overall experience. Frequent violations, or even one or two major violations, will probably anger the audience to the point that they will give up, walk away, and give a very poor rating to the overall experience. It is key that the writer should avoid writing anything that will remind his audience that what they are experiencing is just a story.