I like campaigns where magic items are special. So, assuming that magic items are not a dime a dozen, why not take the effects of enchanted items to their logical conclusion, and see what result that has on the setting? I was inspired by this passage in the Vornheim City Kit, about the medusa Eshrigel:

Once, demons ruled every universe, unchecked. Then came 12 sisters – medusae – they looked upon the demon kings and changed them to stone, and drove the rest away. The grey bones of this earth were hewn from the petrified bodies of these demon kings. Or at least that’s what the 12 sisters will tell you.

…

If Eshrigel is slain, all the statues will come to life. Their details are left to the GM. If the myths are true, about 1/12 of the stone on the planet (and 1/12th of the planet itself) should revert to flesh upon her death.

My first take was to riff directly on this idea. The wilds are peopled with fantastic statues of beasts, giants, and warriors. The statues are ancient, but still have incredible detail. Sages dispute the origin of these statues. Some claim that they were the work of skilled ancient stonesmiths. Others claim that they were the results of ancient wizardry, but still merely decorative work. Some demon hunters claim that the current plague of horrors did not always roam the wilds, and that in past ages when demons directly entered the world they would be turned to stone, forcing them to work from the shadows and control people by possession; this was ended when a reckless warlock figured out how demons could enter the world without being turned to stone and traded the knowledge away.

The truth is that an ancient magic-user ended a great chapter of the demon wars with a powerful wand of petrification. If the wand is ever broken, all creatures that were petrified by it will return to life. (Or perhaps it was a collection of 7 wands, wielded by a secret society of magic-users?) What silly adventurer will break the wand to free a petrified companion, and inadvertently unleash an ancient cosmic war?

I am sure that there are many other magic items that are usually treated with little fanfare, but which could have very interesting setting ramifications. Assuming that these items are essentially artifacts, and not something that can be manufactured, we don’t have the problem of magic-as-technology. I’m certainly not advocating any sort of naturalism. More like investigating what unintended consequences might come from some of those magic items. For example, Plato’s Ring of Gyges is, in D&D terms, just a ring of invisibility. And the sorcerer Thoth-Amon in Robert Howard’s stories derives his magic seemingly entirely from The Serpent Ring of Set, as when he looses the ring he has no power to resist becoming enslaved.