Kurt Vonnegut's eight rules for a short story

From the preface to Bagombo Snuff Box, 1999. He said Flannery O'Connor broke every rule but the first and was still the best short story writer of her generation.

01
Use the time of a total stranger in such a way that he or she will not feel the time was wasted.
this is the one that should hang over every first paragraph.
02
Give the reader at least one character he or she can root for.
03
Every character should want something, even if it is only a glass of water.
the lowest bar in craft advice and it still gets skipped constantly.
04
Every sentence must do one of two things - reveal character or advance the action.
05
Start as close to the end as possible.
reread this one before every outline. I front-load context out of habit and it kills momentum.
06
Be a sadist. No matter how sweet and innocent your leading characters, make awful things happen to them - in order that the reader may see what they are made of.
the rule people quote most and apply least.
07
Write to please just one person. If you open a window and make love to the world, so to speak, your story will get pneumonia.
08
Give your readers as much information as possible as soon as possible. To hell with suspense.
(check the attribution) this gets flattened online into 'no mystery boxes,' which isn't quite what he said.

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