There are very few rules in writing that you can’t bend, break, or ignore – if you do it right.  I’m a believer in knowing the rules and why they exist, but once you understand how to follow them, you can start figuring out how to not follow them effectively.  See, there’s no point flouting something just to flout it – in any arena, I’d say, that’s just a sign of immaturity.  You have to flout rules with a purpose in mind, if you want your writing to be stronger for it.

Some of the rules I will gleefully break if it suits my purposes, and which I enjoy seeing broken to good effect:

• Point of view.  Who says if you write in first person, that you can’t switch perspectives?  Well, plenty of people, but it’s been done by far better writers than me – Emily Bronte did it in Wuthering Heights in the form of a frame character.  Wilkie Collins did it in The Moonstone by having multiple characters give their accounts of what happened as testimony toward the effort of solving a mystery.
• Tense.  Yes, it’s important to keep your tense consistent, and no, you shouldn’t overuse the method, but from time to time dropping into present tense in a past tense narrative can be really effective for times of intense shock, conveying an immediacy and timelessness to a given moment.
• Chronological narration.  Not necessarily the only way to tell your story, although you want to tell it clearly enough that the jumps don’t confuse your readers.  Chuck Palahniuk’s books are narrated conversationally, memories and flashbacks building up on one another and altering the reader’s perspective on what’s currently happening in the storyline, so that what you thought was going on originally is not what you realize is happening as the story unfolds.  This is awesome in that not only are the characters transforming and the story progressing, but the reader is changing as the book goes along, too!
• Conform to a genre.  Yes, this makes your book far easier to market.  But, personally, I’d rather go out on a limb for my own original ideas on the chance that someone in the industry will love it and know how to package it for the masses, than write derivative, stereotypical work that sells just decently and has no impact on my readers.  If Neil Gaiman had written a typical ol’ fantasy novel in a typical ol’ fantasy setting, rather than the original twisted weirdness of Neverwhere, it’s possible there wouldn’t be a popular subgenre of underground urban fantasy now.
• Protagonist = Hero.  Doesn’t need to be.  I love a messy protagonist who does the wrong thing sometimes.  I love anti-heroes.  I love reading from the point of view of a person I’m glad I don’t know personally, but who is fascinating anyway.  If I liked perfect protagonists, I’d be a Superman fan instead of a Batman fan.  I wouldn’t relish Dostoevsky’s work or love Heathcliff of Wuthering Heights so much or have a voracious appetite for Tana French’s mystery novels.

I was told at an early age by an excellent writer that the only unbreakable rule of writing is Do What Works.  Thanks, Mom!