So, if you want to write a story in a fantasy world, you need a fantasy world to work with first. You knew that already and I know you knew that. But did you know that the people who knew it fifty years ago were way cooler than we are? Yep, the past sure was totally amazing, but unfortunately we live in the present and that’s what we have to work with. We can look back at bits and pieces of that way more spectacular time to be alive, but we’re stuck in the now. Gee, wouldn’t it be awesome if we could just choose to live in that time instead?
If you haven’t already caught on to my point, what I’m getting at is the tendency of many fantasy authors to make past ages of their constructed worlds markedly better than the present. If you’re writing a Fantasy book with that concept, I’m begging you to stop here and now. I am 93.6% certain that you’re doing it because Tolkien did it, and that’s the worst conceivable reason to do anything in Fantasy. Not because Tolkien was bad, of course, quite the opposite! But Tolkien effectively made the genre what it is now. And yes, much of his material was collated and modified from Celtic mythology, but his particular blend of it still dominates the genre to this day. You may already be aware that the word ‘genre’ is linked with the word ‘generic’ in more ways than one. So the reason not to do something that Tolkien did is simply this: the mere fact he did that thing means everyone’s probably burned out on it already.
This brings us to my topic du jour, or the mystic devolving world phenomenon. While this is arguably a valid use of certain laws of physics concerning matter and entropy, it happens far too quickly and in entirely the wrong way. Let’s take a look at Middle Earth. In the beginning, there’s one obscenely powerful over-god. He creates a number of less-awesome but still pretty damn powerful deities, and decides to have them sing the world into existence (which is great and I have no issues with). The most powerful of these sub-deities, however, is a self-important jackass named Melkor. Melkor thinks he should control the new world they create, and after a number of divine shenanigans he comes up with the genius idea of plonking himself down on the world and basically ruining everything. In the meantime Elves and Men become a thing. Melkor renames himself Morgoth and divides his power up among a ton of weaker servants, which later turns out to be a tremendous mistake. He is the first Dark Lord and several hundred times more powerful than Sauron ever was (not a canonical estimate, do not use). This is the kind of thing that would be murder for the significance of present action in the books if not properly accounted for.
But it was okay for Tolkien because ‘everything passes on’ was sort of a theme in Lord of the Rings. That was part of what he was going for. Unfortunately everyone still knows about The Lord of the Rings, so you can’t just go nicking its best ideas the way you would with novels that only sold a respectable number of copies. AND DON’T LET ON THAT YOU’RE DOING THAT! It’s not classy for authors to admit that they’ve actually read someone else’s book at some point, and thought some of the ideas in it deserved more attention. What often seems to happen is that some authors notice Middle Earth gets more middling as time goes on and assume that’s what makes a Fantasy world. Not the exploration of a different reality or even the stereotype trappings of Elves, Dwarves and humans, but the idea that things get crappier over time.
Again, this isn’t inherently bad. But unless everything is carefully written to accommodate it, the reader will begin wondering why the author chose to present the most pitiable part of the world’s history to them. This doesn’t raise the stakes, it razes the stakes. I’m sorry, that’s horrible. But you get my point. Most of the world is already screwed up, so what’s the big deal? At this point it would almost be kinder to just let everything self-destruct. It’s not as if there’s much left of the world to salvage anyway! If you want your world to have a history, that’s fine, and if you want everything to be a bit awful so there can be plenty of conflict, that’s also fine. A sort of post-downfall narrative is just fine for stories that aren’t about saving the world. If what you want to do is write a story about living in that kind of world without any prospect of fixing it, wonderful! Make it happen, that could be fascinating. That also makes the ‘decay’ theme far more powerful, since characters are looking at something which has been lost and (insofar as they’re concerned) will never be recovered.
You can also dodge this by taking the opposite route: namely, the world is actually in pretty good shape. It’s just different from what it used to be. Now your contextual history stuff can function properly as context. The past can be discussed idly because there’s plenty of future, and if the present’s pretty great too, then how dare anyone complain? But please, please don’t point to some ancient set of ruins and have your characters effectively say, “Gee, I wonder what this place looked like when it was awesome and not even a little sad. Too bad nothing like this exists now, huh?” You run a pretty serious risk of making the reader irritated that they can’t see the awesome thing, and then they may become irritated because (rightly or not) they suspect that you don’t actually know how to portray the awesome thing.
But maybe that’s fine, if your story is an inverse-Lovecraftian affair where things used to be so wonderful that humans can’t comprehend them. After all, you can break any rule in writing, you just have to break it the right way. Except that rule I just wrote up, that one’s kind of an absolute. I think. These answers were much clearer back during Romanticism.