The Ultimate Guide to Harry Potter Fanfiction

Canon: When to Change it and What to Change

First and foremost, there are some fundamental rules to this that go for almost any fanfic.

1. Never change characters' personalities
Unless you're writing a fanfic where Harry and Draco become friends in first year, for example, where of course Harry would turn into a completely different person. Basically, don't change their personalities for no reason. If you're writing a "what if" type of fanfic, where you're exploring what would've happened if a crucial detail had been changed, like the example above, or if Ginny Weasley had been sorted into Slytherin and thus shunned by her family, or something, then obviously, personalities would be changed. The teenage years are pretty important for shaping who you are as a person, and when a major change like that happens in a story, everything turns out different for that character, at the very least. That's when it's perfectly fine, and almost necessary, to change a personality.

Now, the times when you shouldn't change a personality are when there's no reason for it. Say you're basically writing an OC insert story. Just because you happen to dislike Hermione doesn't mean you should make her the brattiest jerk to ever walk Hogwarts' halls. She is still the same person, and you have to show that. You also shouldn't change the personality of a character for the sake of a romantic pairing. I don't read many fanfics about non-canon ships these days (mainly because I don't read many romantic fanfics these days, though I'll have to read some for when I write romance chapters...), but I remember from the days that I was obsessed with Dramione and read many a cringeworthy fanfic. A big problem I started picking up in a lot of them was that they always changed Draco's inherent personality (or, if the fanfic was a little weird, Hermione's) to make their ship work. That is not okay. Changing a personality for the sake of a ship is frankly cheating. It's so very interesting see personalities change over time due to circumstances the characters can't help, and I'd much rather fanfics that include all that rather than Knut-a-dozen romance scenes.

Long story short: don't change a personality without more than enough reason, and without outlining the circumstances that brought this change about.

2. Never change the laws of the wizarding world unless its crucial for what you're doing
For example, Rowling said the Dementors were taken out of Azkaban when Kingsley Shacklebolt became Minister of Magic, but in my fanfic I need the Dementors in Azkaban for spoilery reasons. It's not very hard to put a little research in and find out all about the Ministry of Magic and the Trace and anything else Rowling ever mentions in her books concerning Magical government (there's literally a Ministry of Magic website, guys, and I heard someone opened it up to Muggles, even). Trust me, if it's mentioned, there's a Pottermore article about it. If you're writing a second generation fanfic, you get some leniency, because obviously things will have changed in 19 years. However, things should be fundamentally run the same.

This section also goes for things like how it's completely impossible to conjure food out of nothing, or Apparate into or out of Hogwarts. Things like this are like the laws of nature in the Muggle world — you can not break them. It's impossible. Trust me, I have tried conjuring food, it doesn't work. And it's quite obvious when people don't put in the tiniest bit of research it takes to discover things like this.

3. Never change what a spell does!
Ever! If you want it to do something else, find a new spell! Or, make one up, because that is perfectly all right. I've done it myself. There are thousands of spells in the wizarding world, and if you need one to, say, change a light bulb, go on Google translate and find out what the Latin word for light bulb is (lux bulbus), and then make it sound more like a spell — luxa bulbiem. If you really want to be fancy, add the word for change, as well. Mash the words together, and there you go. You could also take an English synonym for the word, like phosphorescent for light, and mash it with the (a?) Latin word for change, recensere. End up with something like Recephosphium. It's that simple. Sure, maybe no one will look into your made-up spells name, but if they do, you'll only gain their respect for putting that much effort into your story. Anyway, it's really fun (why do you think I made one of my characters start creating spells?).