I said in a comment a couple posts ago that there are no writing rules -- meaning no hard and fast, unbreakable rules -- and I believe that. It's as easy to come up with the exception to a rule as it is to make one.
But of course there are rules floating around out there, and some writing teachers feel like their students aren't getting their money's worth unless they finish the class with a nice little portfolio of do's and don't's. But usually, if you follow these rules, you end up writing exactly like the writing teacher, and who wants to do that?
Here are some of the rules of fiction writing I've heard over the years. Some are more valid than others, but none are written in stone, in my opinion. What do you think? Have you heard any good, or bad, ones?
* Never write in dialect, that is, spell out how someone pronounces words. You should be able to to convey an accent through word choice and punctuation alone. (I follow this rule.)
* Dialogue should never convey information -- that's what exposition is for. (I like this rule, too.)
* Characters should never speak directly to each other in dialogue. There should always be an element of misunderstanding or not listening.
* At the end of a story, you should get all the characters together in a room. (This might not have been a rule, just a good way to end a story, but I'm not sure.)
* Never switch the point of view in the middle of a paragraph.
* Use no adverbs, ever.
* A word of Germanic origin is better than one of Latinate origin.
* Always say "fuck" instead of "make love."
* Never open with dialogue.
There have to be others, but suddenly I'm drawing a blank.