...Oh! Now I remember!
SO, Fanfiction. Here's my dig on it, partially influenced by various discussions with friends and justifications on my own part. Fanfiction is an art and should be treated as such. Therefore, there are things you should know to write good Fanfiction.

First. TRUE fanfiction requires lots of attention to in-game detail and, in the case of games that take place in areas other than those that the author frequents at any given time (which is most of them), a truckload of outside research. If you're American and the game is taking place in Tokyo and you're setting your Fic in Tokyo, for heaven's sake DO RESEARCH ON TOKYO. Know what the difference is between Shibuya and Shinjuku and what the station signs look like in each. Google maps is a blessing in this. The same goes for any potential Grand Theft Auto fanafics, of which I would really like to see. If you don't live in New York or Wherever and aren't part of a crime family, LOOK UP STUFF ON CRIME FAMILIES. Don't just pretend you know everything, because you don't. I don't.

Second. Know the game inside and out and even upside down. Play it so many times you get sick of playing it. If there's a story, know it. Know all the characters' motives. If there's a part of the game that's sort of part of the story but undoubtedly a game mechanic, consider getting rid of it. Don't write pokemon battles like an RPG and expect the audience to enjoy what you're talking about. If it has nothing to do with the story, KILL IT.

Third. Try to be canon. If there's something you don't like and really can't stand, then yes, perhaps change it. But consider what that will do to the game universe and decide if that is what you really want. Readers are going to expect certain things from good fanfiction, and really what you're doing in any fanfic is retelling a story. Retelling is not synonymous with overhauling.

Fourth. GRAMMAR. PLEASE. PLEASE PLEASE FOR THE LOVE OF GOD IF YOU BELIEVE IN ONE, AND IF NOT JUST PLEEEAASSE.

And lastly; go ahead have fun. Let your imaginations soar and your creative instincts take over. Just don't lose sight of the fact that you're playing in someone else's pen and therefore should abide by certain rules. If you aren't abiding, consider ditching the game metaphor altogether and WRITING YOUR OWN STORY.
I apologize to any of you whom this entry insults. If you care to comment, feel free. I'd love to hear from you (*redies +5 tower shield*).