Here's an article with a breakdown of some written and unwritten rules about speculative fiction
that should be broken. And my thoughts ...1) No third-person omniscient
Variable. My first-readers nagged me away from doing this. As a reader, though, I like it. The main drawback is, as was explained to me in the only writing workshop that was of any use, "Most people spend their entire lives in one head: their own. Jumping around confuses them." I have no way of relating to that, so I just nod and humor the limitation most of the time.2) No prologues
Variable. If you need one for a given story, use it. A concise prologue is better than blathering through an unnecessarily long setup, or leaving readers wondering what's going on.3) Avoid infodumps.
Valid insofar as it means "Don't bore your readers with long explanations." Ideally, information can be worked in seamlessly. When there's a lot, consider chunking it as an encyclopedia entry to somesuch; those sometimes work. Do not simply leave important details unexplained. Confused readers may find something else to read.4) Fantasy novels have to be series instead of standalones
Nonsense. Anything can be a series or a standalone. The mainstream stuff is just the opinion of a rapidly shrinking number of people.5) No portal fantasy.
More nonsense. Many of the classics are portal fantasies. Like any other motif, it can be done well or poorly. Fish-out-of-water stories are at the top of my favorites list, and chucking some poor slob through a portal is a great way to achieve that result.6) No FTL.
Still more nonsense. You want to write or read science fantasy, go for it. You want hard science, just look into quantum physics. There's more than enough wiggle room to fit your plot through if you are careful.7) Women can't write "hard" science fiction.
Downright offensive bullshit. Stab it with pencils and beat it to death with merry bundles of cash.8) Magic has to be just a minor part of a fantasy world.
Dependent on subgenre: this rule is valid for Low Fantasy but not for High Fantasy and most other subgenres.9) No present tense.
More valid than invalid, but not an absolute. It's a literary technique that works well for specific types of stories, but not so well for general use. Many readers find it awkward to read and would rather read the usual past-tense instead. Don't use it unless it's really needed.10) No "unsympathetic" characters.
A poorly phrased expression of valid concerns. 1) Make sure the readers have someone to root for. If all your characters are assholes, nobody will want to spend time with them. 1b) Don't make villains so sympathetic that readers are torn between sides to the point they'll be unsatisfied with the ending no matter who wins. That way lies throwing the book against the wall. 2) Make sure characters have motivations for what they do, even if the reasons are crackpot ones. If the actions don't make sense, that tends to annoy readers. 3) Engage the readers in caring about the characters. If the readers don't care, they will quit reading.
Note that it's easier to do this stuff with sympathetic characters than with unsympathetic characters, and that doing it also tend to make even evil characters more understandable and thus more sympathetic even if readers don't want them to win
. If you've got a good supply of sympathetic characters, they can carry one or a few unsympathetic characters. If the cast is all grayscale (anti-heroes and conflicted villains, etc.) then a completely unsympathetic character may capsize it.
Finally, look how many of these "rules" are really just fashion statements. They're backlashes against the fact that people have overdone a lot of good motifs. This especially applies to 1, 4, 5, 6, and 8. As a writer, write the stories that grab you and won't let go, regardless of how they fit -- or don't fit -- current fashion. Those are the stories most likely to grip an editor and readers with similar force. As a reader, read what you like. Don't let anyone tell you what you "should" like. They're your eyeballs, you choose where they go.