One thing to avoid is going too far from the established lore of the 'Game of Thrones' universe. The fans are very familiar with the world, its history, and the rules. If you deviate too much, it might not be well - received. For example, changing the basic nature of the White Walkers without a good explanation. Another thing is creating out - of - character behavior for the main characters. If you make Arya act completely unlike herself, it will seem off. Also, try to avoid over - using clichés like the 'chosen one' trope too much in your story.
When writing a 'Game of Thrones' fanfic, you should avoid inconsistent power levels. In the original series, the development of a character's power, like how a wizard or a warrior gets stronger, is usually a slow and well - thought - out process. If you suddenly make a character super - powerful without proper build - up, it will break the immersion. Moreover, don't just copy the plotlines of the original series. While it's okay to be inspired, your fanfic should have its own unique story. And of course, as mentioned before, avoid any inappropriate or offensive content that doesn't fit the general tone of the 'Game of Thrones' world.
Avoiding plotholes is crucial when writing a 'Game of Thrones' fanfic. The original series is known for its complex and interwoven plotlines. If your fanfic has big holes in the story, like a character suddenly disappearing without any reason or a major event that has no consequences, it will be a turn - off for readers. Also, don't neglect the cultural and geographical aspects of the 'Game of Thrones' world. Each region has its own distinct culture, and if you don't respect that in your writing, it will seem less authentic. And finally, stay away from writing a fanfic that is just a vehicle for your personal biases, for example, making a character you don't like always be the bad guy without any real development.