Tips On Taking Inspiration From Real-Life Myth, Lore, Tradition, & Legend Without Looking Pretentious, Ignorant, or Insulting
Taking inspiration from real-life lore and whatnot can be a great way to build up a setting, but if it's not done with a certain amount of care and caution it can backfire spectacularly - so here are a few tips to help you avoid making some of the bigger blunders out there when you're trying to do this.
First off, do a lot of research. You might find that something you're thinking about using is actually intrinsically linked to a much larger belief system or cosmology that doesn't actually mesh with what you're trying to do in your setting - in which case, it might be better not to use it lest your setting feel inconsistent and/or haphazardly constructed. Or you might find that a word you were planning to use doesn't actually mean what you thought it meant, and that you might be better off using another word instead. (EG, the word rune refers to a character of the runic alphabet. For magic symbols in general, the term you're looking for might be glyph or sigil). Or you might even thought that something you thought was part of ancient lore is actually from fairly recent history instead!
Also be aware that there are a lot of bunk sources. Unfortunately, there's a lot of nonsense out there, and it's not always easy to weed out. But there are a few red flags to watch out for - anything that talks about a whole continent or other large region as if it is or was a cultural monolith is definitely a source to be wary of. Same for sources that try to conflate deities or creatures from different mythologies with nothing more to connect them than the fact that they have few traits in common. Another thing to watch out for are sources that refer to deities as "the god/goddess of [1-2 traits]." (Few deities could ever be sufficiently described so briefly, and there was often overlap between their areas of influence!) Also, whenever you do your research make sure you look into multiple sources - don't trust any one source to have all the facts.
Don't turn somebody else's religion or spirituality into fantasy hocus-pocus. That mystical-looking person, holding that ritual with the chanting might not be doing anything more "magical" than a priest praying for a blessing is. That unfamiliar ceremony you see might not supposed to be any more "magical" than a Communion. So before assuming that somebody else's practices are supposed to be some sort of magical affair, do your research - make sure you're not turning someone's religion or spirituality into some kind of fantasy magic type stuff.
However, if it is or was commonly accepted to have no specific or exclusive religious connotations per se, then it's probably all good to use in a magic system. For example, the concept of magic crystals ties into old beliefs that certain stones had special properties, but as this concept doesn't hinge on any specific religious belief, magic crystals are all good. Likewise, the concepts of spells, magic wands, and potions aren't exclusively tied into a specific belief system, so they're good, too. The main question to ask yourself is, "is this done or believed in pretty much exclusively as part of a religious tradition, or does the concept exist without any specific or exclusive religious context?"
Remember that just because two things are similar to each other, doesn't mean they're the same thing or that one is another "version" of the other. If you do some research, you'll often find that even though two characters or creatures might be very similar in what they do and how they act, their origins and surrounding myths will reveal that they really don't actually relate to each other at all. Or you might find that just because its name has been translated to a familiar English word (EG, such as how youkai has been often translated into demon), doesn't mean it should be considered to be the same entity as the one you're familiar with.
Remember that not everything fits into the same paradigms and organizational structures. When researching lore and whatnot, we often try to fit it into structures we're familiar with, whether consciously or unconsciously. For example, many people familiar with Christianity tend to assume that everything should fit into some sort of good versus evil paradigm, when that's actually rarely the case. Those familiar with Greek mythology might assume that the gods of other pantheons must all fill the same archetypal roles as the Olympians, which just isn't the case. So when you do your research, try to set aside whatever preconceived notions you might have about the way things ought to be, and instead try and focus on what is.
Resist the urge to include or explain everything that strikes your fancy in your setting. Using just anything that strikes your fancy, regardless of whether it actually adds anything of substance to your setting, just comes off as tacky and gimmicky. Also, if you have to completely change around a defining trait or characteristic of something to make it fit into a core mythos you've already developed, or if you have to explain its existence in such a way that a defining trait or characteristic is completely negated, then you should probably just leave it alone - because at that point, you're probably trying too hard and are just going to end up making a complete mess of things.
Don't take something away from its originators. It can come off as patronizing, callous, insulting, and even mean-spirited to take something done or practiced by real people and portray it as having been part of your made-up mythos all along - doubly so if you paint those who actually do or did it as being nothing more than wannabes or shams. The same goes for taking a real-life tradition or practice and portraying it as something that those who were savvy to your made-up mythos invented and gave to these people. It also goes for using particular mythological elements as part of your worldbuilding, but failing to include the actual people it came from in any meaningful way - EG, your worldbuilding draws heavily from Chinese lore, but none of the main protagonists are or look Chinese.
Before you try to reinterpret or reimagine something, make sure you understand it - and understand why and how it came to be. You can't properly reinterpret or reimagine something without understanding what it was really all about in the first place. So if you wanted to do this with, say, Medieval werewolves, you'd want to look up both the lore surrounding them and the cultural context in which the lore developed. If you want to reinterpret or reimagine some witch hunt or other, you should first understand the reality of why witch hunts happen.
If you can't find something that really fits, consider borrowing traits and concepts instead. Rather than trying to shoehorn, say, some preexisting shapeshifting monster into a setting that really isn't a good fit for it, why not create your own shapeshifting creature? Sure, it's fun to borrow stuff from real-life myth and lore, but don't overlook the fact that stuff don't necessarily need to have years of lore and legend behind it to make for a good story.
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