I’ve been throwing around the term fictional reconstructionism for a little while now and the longer I sit with it, the more I like it as a term for what I do.
Fictional recon is a kind of pop culture paganism. It would include things like Serenitism and the Season Guardians but not writing, say, a Buffy-themed spell. Reconstruction is the process of looking at the record we have of a no-longer-extant religion and rebuilding it; fictional recon is applying that same combination of textual analysis and trial and error to a fictional source instead of a historical one.
Looking at, say, LotR or Dr Who and wondering what those religions looked like. How would it work? Who would you call on? The way you come to understand a religion like that is as a framework on which you hang your own understandings and preferences in a religion. Fictional recon is also an exercise in self-knowledge because you need to know what you want to get out of a religion.
In building a relationship between yourself and a “fictional” deity, you’re reaching out to the Powers and saying ‘this is what my life is missing; does it exist?’ and preparing to accept the answers.
Some people doing things that would be classed as fictional recon are no doubt doing it as soft polytheists, monsters, or even atheists. I personally approach it from the POV that I am reaching out to see if anything answers to these names and paradigms. Not every experiment is successful, and not every successful experiment results in a relationship I want to pursue. But if a being answers to the Doctor, and he quacks like the Doctor, and he offers jelly babies like the Doctor, well, when he offers me a ride in the TARDIS, I’m going to go with it.