No, this is not a post about how to hide the fact that your car is stolen. Among fan-fiction writers, the expression ‘filing off the serial number’ refers to the act of removing all references from a fan-fiction story and turn it into an original one which you can then publish or sell.
I’ve decided to turn two stories I’ve plotted out - and in one case written completely - as fan fiction into original ones. One, already written, is “The Lady of the Dead” which is based on the “Johannes Cabal” series. The other, “On An Adventure”, is set in a possible future of the world of the web comic “Girl Genius”. Both of them, however, share little with the original intellectual property they come from.
“The Lady of the Dead” is, theoretically, featuring two granddaughters of Horst Cabal, Johannes’ older brother, but is set in a time shortly before the actual series (the setting of the series encompasses elements from late Victorian times through to the 1950s).
“On An Adventure” is set in a time after the events of “Girl Genius”, as two of the characters are descendants (at least great-grandsons) of characters to be found in the series. While the setting - and especially the Steampunkesque technology, which plays a large role in the web series - remains similar, I am not using any real characters and the references to specific families can be removed. As only one story of “On An Adventure” is written already and five are not, changes can be made easily before I commit to the stories.
In case you also want to do that - as others have already done with great success (“Fifty Shades of Grey” started its life as a “Twilight” fan fiction, for instance) -, here are my suggestions for what to consider and what to do if you want to file off a serial number and turn a fan-fiction story into something that will work on its own.
The very first step here is to ask yourself if you really, really, really want to do that. It’s a very long and very challenging process and it might sometimes be faster to write a new story with the same plot points, but with original characters in an original setting.
If your fan fiction is set in an alternate world (an AU, as fan-fiction writers call it), chances are you will already have an original setting and you might already have made quite some changes to the characters, too. Yet, you are still relying on the audience to be aware of the characters and their background and the general plot beats of the original story. All of this will no longer exist, once that serial number is off.
If your fan fiction is very close to the original setting, on the other hand, if you add scenes or an additional story to what is canon, then it will take a lot of work to break away from all of that and make it something original.
Don’t forget that, in both cases, your new audience will have no reference for anything which happens - setting, characters, and back story will have to be explained again because they’re not part of a known intellectual property any longer. Instead, you will have to provide them.
If this sounds like an awful lot of work, that’s because it is. It will in many cases probably be easier to write a new story, drawing on the plot points of the story you want to transform, than to turn this finished fan-fiction story into something original.
At this point, ask yourself if it’s worth it - if you believe enough in your stories to invest that time. I do believe in both of my stories or I wouldn’t do it.
Once you have decided to file off the serial number, the next step is to go through your story, as you would during a content edit, and mark every reference to the original you worked off in a strong colour like red - names, specific expressions, references to the canon stories, whatever is connected to the intellectual property you worked with. All of this will have to go. After you did that once, do it again - trust me, you’re always missing something on the first time through.
After you’ve marked everything and have an idea of what you need to replace (a lot, normally), the next step is to figure out what to replace it with. Names are usually the slightest of your problems - everyone can come up with new names. Other expressions are similar to that. Background information like the characters’ back stories or the history of your setting are much harder to do. Worldbuilding is always challenging. Now, if you have an AU, worldbuilding will already be done and things will be a little easier.
Another thing you need to think about is how to convey all that new information. In a fan fiction, you can assume that the audience knows about all those things - because people usually don’t read a fan-fiction story unless they’re familiar with the original intellectual property. With your own story, you need to give people all the information about the world they need to understand everything happening.
For instance, “On An Adventure” starts with Maria, one main character, having the choice between two suitors from the same powerful clan - in the fan fiction, those are descendants from the Heterodyne and Wulfenbach families (yes, I ship Agatha and Gil, if only because it would drive Gil’s father bonkers) which play a major role in the web series. I can no longer use those, so I will need to fit in something about the past of the world and how those two houses rose to power. I need to recreate the background for all of my main characters, because they’re all related to important families of the “Girl Genius” web series.
On the other hand, “The Lady of the Dead” has a few references to Horst Cabal and his nature as a partially-healed vampire. These will be easy to remove and play no large role in the narrative. I can simply ‘invent’ another daywalker or suchlike. Apart from that, because of the changed setting and timeline, “The Lady of the Dead” is pretty original already. There are names to change, there are some small changes in the narrative, but the story of Joanna and Alice (who used to be Johanna and Alisha - since the name ‘Horst’ has no female version) can play out very much the same way without serious exposition dumps.
Filing off the serial numbers can be a step from the world of fan fiction into the world of a professional author, even if that author might still be self-publishing. Yet, do remember that filing off the serial number is only one part of the process of publishing your own work. Once the story is completely free of other people’s content, it still needs serious editing and revising before it can be put out for all to see - and read.