Well, considering I’m in the middle of writing my third mass crossover fanfic, and am planning a fourth, I thought I would discuss this topic.
Crossover fanfiction–it’s not original, it’s not popular, but it’s been done multiple times. The question I want to ask is, why is it not popular? I mean, putting two stories together, and I presume that these two stories have their own fanbases, what’s not to like? The fact is, there are a number of things that can go wrong.
Yes, you have to prepare before you can actually start writing the crossover. Before I wrote mine, I’d seen the Lord of the Rings movies about fifty-two times (the theatrical versions and extended versions) and I’d seen Kingdom of Heaven about fifteen times (theatrical and director’s cut). I’d done a literature research for school on the two texts, focusing mainly on Balian’s psychological growth, and how Legolas and Gimli learnt to accept each other and become friends. I’d also read the LotR books a few times, and done some reading on the Crusades. To write a crossover, you need to know the character very well so you can write how they deal with being thrown into this bizarre situation. You also need to do some research about the characters’ backgrounds, and think about how this would affect them as people.
I cannot stress how important this is. People only read crossovers because they’re interested in those characters, and how they will react in this entirely strange situation. They want to see the characters they know and love, not people who share the same names and nothing else. You need to be able to describe things in relation to the character’s experiences. For example, Balian compares everything in Middle Earth to his village in France and the Holy Land, because those are the things he knows. If I’d had, say, a Roman soldier in Middle Earth, he’d be comparing everything to Roman things.
Tip: I suggest sticking to the original canon plots as much as possible, and only changing what you really need to change. However, you have to take into account the fact that because you’ve merged these two or more stories, the plot is definitely going to change. The visitors should not change the plot too much though. A good way to prevent this is instead of having them as the centre of everyone’s attention, have them on the periphery, and then tell everything from their point of view. That allows you to step into their shoes. Also, research their background and the sort of world they come from. If it’s a modern insert, then you probably can use your own experiences, but remember, if you’re trying to do period pieces, people are going to think differently from the average modern day person. Research is everything, and anything that research doesn’t answer, you can fill in with your own imagination.
This is much easier. For my first crossover, I just followed the plot of Lord of the Rings, with an extra character or two. Sometimes, the characters want to do one thing but you want them to do something else. Go with the characters. They know what’s best for your story. Your job is to write down what they think they ought to do, and throw in some random events so they can have a reaction. I suggest not changing any of the outcomes of the original story, if you’re following a canon plot. You can take a slight detour — in fact, that is encouraged.
Use of movie/book dialogue
Sometimes, it’s impossible not to use lines from the movie or book, but try to keep it to a minimum, since if your readers want to read a rehash, they can just search out the script. And I suggest you add your own commentary if you have to use the movie lines. If you don’t think you can do the characters justice with your own dialogue, then perhaps you shouldn’t be writing the story at all, since you don’t know the characters well enough. Do not, and I stress this, do not write out the script and then insert a few lines about your other character here and there. It doesn’t work.