The classic Western-fantasy adventuring party, appearing across a wide variety of media and baked into what Dungeons and Dragons in particular expects adventuring groups to be capable of, consists of four very different characters. By default, there is a “fighter,” who wears armor and specializes in swordplay or another close-range martial art; a “wizard,” who is a combination mobile artillery piece, library, and miscellaneous magical toolkit; a “rogue” or “thief,” whose specialty is stealth, lock-picking, smooth-talking, acrobatics, and similar skills; and a “cleric” or “priest,” who provides the favor of the gods to their allies, usually in the form of magical healing and defensive magic.
That last person raises difficult questions about the overall shape of the fantasy universe, which every D&D setting tries to answer one way or another. It’s not difficult to imagine a fantasy world where the term “cleric” means something more like what it means in our world, and refers to someone an adventuring party might visit afterward for wound-tending and soul-cleansing rather than a steadfast and magical battlefield ally. Ivanhoe is probably the work of fiction most famously within this tradition. But most Western fantasy assigns clerics and other agents of the divine power well in excess of the demonstrated abilities of real-world religious figures, including the power to raise the dead on demand, instantly heal deadly injuries multiple times a day, and brandish holy symbols to disperse zombies. The deities of a fantasy world that is home to this kind of priest are, thereby, much more powerful than the god of Ivanhoe and any deity associated with real-world religious practice, and have far more direct and overt effects on the world at large.
Inevitably, this creates a far more urgent version of the problem of evil: if the gods are so powerful, where are they? And why do they do almost all of their work through mortal proxies?
Most fantasy worlds establish a distinction between mythic time and historical time, while treating both as the true history of the world. In the world’s mythic past, the deities are active in constructing the world and, almost always, come into conflict with one another over its shape. In mythic time, the deities are accessible, physical beings who behave in human-like ways. Part of what makes Western fantasy worlds full of magic is that they were almost all created by deities in ways our world most definitely was not—but it is very hard to write a world with active deities where mortal heroes have something to do. So, fantasy worlds almost all rein in their deities, dreaming up cosmic pacts, depleted reserves, and magical barriers that prevent these otherwise nigh-omnipotent entities from rearranging coastlines and conquering empires at their leisure. Whether they move to distant planar abodes, climb to the top of Mount Olympus, or simply stop being around, eventually, the deities are no longer moving about the world and exerting their power over it. Eventually, the gods always switch to influencing the world via agents, usually mortal. Even deity-like creatures laboring under no such restrictions are distant and subtle, preferring to avoid direct attention even when it is plainly easier for them to just show up somewhere and squish some upstart beneath their clawed heels. Adventurers still at the “clearing giant rats out of tavern basements and putting out barn fires” stage of their careers have no recourse if Thor or Dagon decides they’re a problem worth personal attention. If the gods are active, then they’re the characters worth watching, and the mortals in the story matter about as much as ants in an ant farm. But if the gods are inactive, a whole new series of questions arises: Why do we care what they think? Why do I pray at roadside shrines? Why do I complete quests for their representatives? Why does what they want affect my behavior at all?
Active deities steal the show. Inactive deities are irrelevant. Every fantasy world finds a different compromise between these two facts, usually settling on “whatever you think about the gods, the clergy are magic.”
There’s a sense in which even worlds in which deities are explicitly real can’t really treat them that way without ceasing to make sense to their mortal explorers. Our world works the way it does because deities aren’t real, or more precisely, because our world’s deities can’t be distinguished from deities that don’t exist. Deities can be the hand-wavy justification for why the characters who call themselves priests can be way, way better at healing than the average apothecary, they can be the source of coy omens and the implied authority behind religious hierarchies, and they can even provide searing sunbeams of holy righteousness as weapons for the devout, but the moment they take an active hand in the world, the questions immediately arise:
What the fuck took you so long!? If you could deal with Monsterface von Bigbad just like that, what did you need us for!? Was this really all so you didn’t have to get up from your Sudoku long enough to save the universe!?
Most fantasy worlds have more evidence that deities exist than ours ever will. In most settings, one can physically visit the sun god’s palace, stand in front of them, have tea with them, discuss current events with them, and slap them in the face if they permit it. And one very well might want to, given the sun god’s habit of aggressively dictating mortal morals.
But with or without deities, the Western fantasy world is a mortals’ world. Mortals move events, mortals solve problems, and mortals make the decisions that matter. This is not just a narrative convenience. The world can be full of magic and manticores, but it needs to fulfill a baseline similarity with the real world to be comprehensible to players. This is part of the same verisimilitude that mandates that the world have gravity, integral to the world making sense.
That’s not a coincidence.