myself hate the way D&D and other fantasy games treat polytheism as an objective fact of the world. That is, rather than treating polytheism as something that some cultures believe (with different cultures having different beliefs) it treats the various gods as things that absolutely DO exist and everyone KNOWS they exist. This leaves no room for any other types of beliefs to exist.
How is that different from any religion? If a religion believes in God then they are going to treat it as a thing that absolutely exists and everyone knows it exists. Some how that does not stop any other type of belief though.
The difference seems fairly clear to me: the various campaign books, which are full of information about the campaign world, tell us that there are multiple deities. That is, they present polytheism as a fact about the world.
I guess it would be
possible to treat the campaign guide as, in fact, a religous tract written by a particular adherent. But that's not how D&D campaign guides are presented. (Compare, say, Glorantha, which does present the cosmology from various ingame perspectives, and so does not settle theological disputes in the voice of the impersonal, factual, third person narrator.)
I'm fairly confident in my point here. DND has always been polytheistic.
And I'm equally confident that classic D&D, with clerics and paladins wearing heavy armour and wielding heavy weapons, and performing miracles most of which have a fairly obvious provenance in real-world traditions, makes it trivially easy to run the game as implicitly monotheistic. Even moreso when anti-clerics and evil high priests are treated as foul sorcerers and traffickers in demons (with their spells that animate the dead, inflict injury and death, cause darkness, etc).
It's only the change to spheres of clerical magic, domains, specialty priests etc that makes this harder. Which is why I, at least, would single out later editions.
Which in my view immediately makes the world polythestic by definition, in that as far as I'm concerned the ability to grant spells is what makes a deity a deity...which means those dark spirits just got promoted.
Well clearly there are real-world beliefs about the ability of dark spirits to grant magical powers which don't involve attributing the status of god-hood to those spirits. I am envisaging that one would understand anti-clerics and evil high priests (and the dark spirits that empower them) through the same sort of lens.
The concept of divine providence is not unique to monotheism: "A plague killed your crops and infant child? You must have done something to offend the gods, so go to the temple and sacrifice a bird or offer some grain offerings." This strikes me as an inherent problem of the cleric class, as it mechanically cordons off miracles to the realm of clerics (and paladins, to a lesser extent).
I agree with this. In my 4e game, I handle it in an informal way: because 4e is quite relaxed/flexible in respect of improvisation, the contrasts between power sources and their origins, the ingame meaning of dice rolls or power expenditure, etc, it is fairly easy to allow the narration of outcomes to encompass divine phenomena (if that seems appropriate to the player or the GM) even when the character involved is not wielding the divine power source.
I think approaches to D&D that take a stricter view of the things that 4e is relaxed about, though, probably make the issue harder to smooth over via informal devices.