First, familiarize yourself with the basic concepts of chaos theory, like the butterfly effect. Then, think about how you can incorporate these into the fate - based world of your fanfic. For example, you could start with a simple event that has a far - reaching impact on the characters' fates.
To start a 'Chaos Theory Fate Fanfic', you should first decide on the scope of the chaos. Will it be a small - scale chaos that only affects a few characters or a large - scale chaos that reshapes the entire world of your fanfic? After that, you can start building your plot around the initial state of fate for your characters. Consider how different events, which seem random at first, can gradually change the course of their fates. It's important to keep in mind that every action should have a reaction in the context of the chaos theory, so plan your story accordingly. You might also want to do some research on different cultural beliefs about fate and how they can be blended with chaos theory concepts to make your fanfic more unique and engaging.
Begin by creating your characters and their initial fates. Then, introduce elements of chaos. It could be as simple as a random prophecy that throws everything into disarray. You need to make sure that your story has a clear direction, even though chaos is a major factor. You can also look at other fanfics or works in the fate genre for inspiration on how to set up the world and the characters' relationships.