Lists, such as "25 Symptoms of...," "50 Reasons Why...," etc.
Stories in script format. This is only acceptable if it's in genuine screenplay format and is extremely well-written.
Songfics with 5K of song and only 1K of story. Properly written, songfics are just like any other story, only they have the lyrics to a song inserted at appropriate places.
This site has a screening process for quality control. There is a Committee of authors who review stories that are submitted to the site and vote on whether or not to approve a story for posting. If a story is rejected, the Committee members will give them advice on what they can do to improve their story and their writing. This helps authors to improve their work, and keeps the quality of stories on this site at a level that the readers have come to expect. If your first story is rejected, don't give up. Many authors have had several stories rejected before they get a story approved for posting, and there's always a drastic improvement in the quality of their writing.
Not Necessarily Rules, But Things I'd Like People To Avoid:
No flaming/trolling. This means no reviews along the lines of "This story sucked" or "You suck because you had Cloud fall for Tifa." That doesn't mean your reviews have to be glowing, but it does mean you need to offer constructive criticism. If you don't like a story, give real reasons for why you didn't like it. Also, no author bashing.
Reviews will be monitored to ensure that these rules are followed.
Over 600 fanfics have been rejected since the advent of the Fanfic Approval Committee back in October of 1998. There have been many reasons why stories have been turned down; these are some of the most common. Keep in mind that, for the most part, these are general guidelines and if done correctly, many of these rules can be bent or broken. These tips are not meant to scare away new authors. They are meant to help people improve upon their writing skills. Breaking a few rules doesn't necessarily mean your story will not be approved. However, breaking some of the top rules (spelling, grammar, tenses, etc) can prevent approval.
The tips above the break are the most important ones. The ones below it are merely tips and advice.
Bad spelling. Read through your story again and run a spell check. Make sure you don't have words misspelled, misused (there, they're, their, etc.), or otherwise incorrect. Always be sure that you're spelling the names of the characters and locations correctly, too (it's Crono, not Chrono; Aeris, not Aeries, etc.)
Bad grammar. Make sure you don't have any run-ons, sentence fragments, or comma splices. Look your story over to make sure it's free of grammar errors.
Mechanical errors. This would include switching tenses back and forth (for the record, it's always recommended to use past tense in your writing,) the misuse of punctuation and capitalization, and spacing errors.
Start a new paragraph when a new character speaks! This is a huge mistake that's made all the time, and it can be a killer.
Don't insert Author's Notes into the middle of the story. Wait until after the chapter to do so.
Never, never, never use emoticons in a story ( :-), ^_^, etc.)
Don't write short chapters. Chapters that are only a few paragraphs aren't nearly long enough and should be expanded or combined with other chapters.
When you submit, be sure that there's enough for us to judge by.
Lack of detail. I can't stress enough how important detail is. It lengthens the story and makes it more interesting. Detail also helps to prevent the plot from making sudden jumps. It's the old adage of "Show, don't tell." Don't just write:
Remember that fanfics are stories, not games. That means certain elements need to be removed, such as HP/MP, save points, and overuse of healing spells and ultrapowerful offensive spells such as Knights of the Round.
Stories should be longer than a page. Most SHORT stories have absolutely no detail and no plot, and even if it's a good short story, people will probably automatically look down on it because it's short. Almost nothing can get said in a page. A story must have a beginning, a middle, and an end.
Pointless comedies. Don't write a piece just because it seems funny to you. If there's no point to the story, there's no point for us to pass it. This doesn't mean that comedies are bad; far from it. Comedies can be extremely good if they're done correctly. However, correctly doesn't involve a screenplay format, game show parodies, or the cast of FF7 sitting around cursing with the South Park kids. Write the comedy within the boundaries of what could possibly happen to the characters in the game or series being written about. Humor is generally funnier if it's set in a realistic setting. Also, steer clear of pointless character bashing (e.g., EHEHE RINOA SUX SHEZ A FUKKIN AIREHED), immaturely poking fun at traits of characters (e.g., Tifa's breasts), overdone pop references (I've seen things from Eminem to McDonald's to Springer), and there's just a lot of shallow "humor" within the fic (e.g., Barret: *smacks Cloud in back of head* | Cloud: MY HAIR! *dies*).
Pointless crossovers are a no-no. Don't just have two games mix without a good reason. Also keep in mind that the characters from different games don't know each other, so write the story as such.
Be original. There's already a ton of stories out there on the following topics:
Try to avoid using a title that's already been used on the site. This doesn't prevent your story from being accepted, but it does help to avoid confusion.
Always spell out any numbers less than one hundred. It's really obnoxious to read about 6 types of materia or a 2 year old brother. Really, it's not that hard to type out those two extra characters, and it's much more pleasing to look at.
Use synonyms. Don't repeat the word "said" over and over again.
Characterization. This is mainly relevant to authors who introduce their own characters. Don't just bring in a new character and expect people to automatically care about them. Give the people a reason to like/hate your character. Give them a history, relations, and everything else you would expect out of a character. Introduce the character slowly; don't just cram him down our throats.
Plot development. This goes along the same lines as characterization. Make sure your plot is believable.
Don't have a character act out-of-character for no reason, such as having Gremio suddenly burn down a village simply because he was bored. Know the characters' existing personalities and histories before you start writing.
Characters such as Kefka, Sephiroth, and Aeris suddenly being alive again for no reason. Face it, they're dead. If you insist on bringing them back, at least have a really good explanation for it. Your best bet, however, is to just let them rest in peace (or pieces.) If you really want to write about them, write about something that happened before the game.
Excessive violence and sex. These are usually just thrown in there for shock effect. Guess what? It doesn't work. It just detracts from the story, is usually out of place, and seems juvenile. Violence is fine if it fits with the rest of the story, but don't throw it in there just for the heck of it. Sexuality is fine, but just keep in mind that if it's overdone or done wrong, it looks like it was written by a 13 year old kid. Sex is acceptable if done in a tasteful way (and no, that doesn't mean that Tifa spits) and if it isn't gratuitous.
Vulgarity and cursing are fine, but use them in moderation, and don't throw them in just for shock value (again, it doesn't work.) I'm really leniant on cursing, so a story probably won't be rejected for language unless the author just goes overboard and is cursing for the sake of cursing, or if it's intentionally offensive (racial slurs and the like.) Avoid cursing in narration unless it's from a character's POV. Lastly, if you're going to curse, go all out. Don't ever say "d@mn," "S&%$," or "F*^#." Use the actual words (comedies can be an exception, but even then it's not always a good idea to censor.)
In battles, write descriptions of the moves rather than naming them (don't say "Crono cast Luminaire" or "Squall cast Ultima." If you're going to cast the spell multiple times, at least describe it the first time; then it's slightly more acceptable to simply name it afterwards.) Also refrain from using HP/MP, status conditions, or turns. Those make it seem like a strategy guide.
Watch your dialogue. Make sure that it isn't cheesy, and make sure that it is believable. It helps to go back through your story and read it out loud to make sure that the dialogue sounds natural.
Remember the normal patterns and nuances of speech. In real life, people joke, interrupt each other, pause mid-sentence, stammer sometimes, etc. Nothing's worse than a scene where two people just spew canned lines at each other and "take turns" saying things.
Don't use real-world references in a game where they don't belong (popular songs in FF7, movie references in Xenogears, etc.) There are very few games where these types of things would fit (Parasite Eve being the most notable.) Pop culture suddenly makes a fanfic a crossover with the real world, with no meaning for the crossover or further representation of why it occurred, leaving a big gaping hole in the plot.
If you're going to kill off a character (especially one from the game,) be sure you have a good reason for doing so. Don't kill a character simply for shock value. Make it matter.
In after-game fics, don't always feel compelled to introduce a new villain whose power goes far beyond that of the final boss of the game.
Be careful with your villains. Give them some real motivation. "I want to rule the universe" is an old standby, but it's becoming quite overused. How many people would really want that? How many could handle the responsibility? It's also helpful if you can see the human side of the villains and bring that out, making them a three-dimensional character instead of some cardboard cutout that wants to DESTROY ALL THAT IS GOOD. As someone famous (whose name escapes me right now) once said: "The audience hates a good villain, but loves a great one."
Love pairings for the sake of creating a new pairing (not to mention making combinations of two people's names to form a "cute" portmanteau word (e.g., Quiefer = Seifer + Quistis)...I can tell you one thing: it's NOT cute). Pairings aren't very good if there isn't any chemistry to begin with, but they're even worse when there's no development to help make up for/create that chemistry. But if you can make it believable and make sure that it works, then by all means, go ahead.
Only decribe stuff relevant to the story, unless it's a stream-of-consciousness story. Nobody wants to hear about underwear in the middle of a battle, unless the main character is actually trying to take his mind off the killing.
Don't use slang unless a character is saying it. The quality of a story suffers when people use tons and tons of slang that's NOT in dialogue. (slang in dialogue is okay as long as the character who's doing the talking is one who would actually USE the slang. [ie: Vincent would NOT say "That's totally whacked, dude."])
Please don't insert music into a fanfic. It usually takes away from the story, and odds are very slim that your readers will actually have all the songs readily available to them. Actually, there's a good chance that they'll never have heard of most of the songs.
No new technology should be in a fic without an explanation of how it works or why it's there. Period. You don't say, "So and so stepped into the atom regenerator and their wounds healed."
Never, NEVER rush the story just to 'get it in' before someone else does, or for instant fame...or for whatever reason. Believe it or not, a good story takes time. And nothing destroys a story faster than lack of time spent for thinking/writing. And who knows? If you spend just a little longer on it, your story might turn out original, even if you weren't the first to "post" the idea.
For a quick checklist, you can look over Jerm's Guide. Note: This is a joke, and by no means scientifically accurate, but it still has some valid points.