Priests and Mages in the same setting
 

In one setting, mages perform magic using ritual magic (M200, Thaum72). Astrological modifiers apply, and mages need some sort of applicable correspondence to cast any spell, even if it’s just a bit of iron for a Fire spell. That being said, I’m thinking about allowing non-mage priests to work miracles, subject to various limitations: the ceremonies are lengthy, require a sacred place in which to perform the ceremonies, and though the ceremonies only absolutely require the sacred place, appropriate attire, incense, offerings and other such trappings are very beneficial. I’m wondering which systems to use for priestly magic. Oh, and there are mage-priests. They can and do perform normal magic in addition to priestly miracles.

Re: Priests and Mages in the same setting
 

Have you looked at Divine Favor?

Re: Priests and Mages in the same setting
 

It sounds as if Mages and Priests both use Ritual Magic, but have quite different requirements and sets of bonuses.

You may wish to reserve some spells, or even colleges, for one or the other kind of spell-caster. You probably also want to use Power Investiture as a required advantage for priests who can do miracles.

Re: Priests and Mages in the same setting
 

I think my best option is for priests to use Path magic and Power Investure. Generally speaking, since Religious Rank, in a hierarchal church at least, mostly relates to political and administrative prowess, Religious Rank and Power Investure are unrelated. There are even some individuals who have Power Investure without Clerical Investment, though this is rare.

Though I’m inclined to restrict most of the college of necromancy, as well as other spells dealing specifically with spirits (Awaken Craft Spirit, for example), to priests, this does lead to a fairly obvious problem: what kind of a god would empower demon summoning, the creation of the undead, and similar?

Re: Priests and Mages in the same setting
 

This is only a concern if your setting is monotheistic instead of having a pantheon. But there's always the option of either reskinning the demons summoned to divine punishers and the undead as "blessed dead". You could also just fiat that priests do not have access to the "evil" spells.

A third option would be that priests do have access to these spells, but those are temptations from demons, evil spirits and entities like the Outer Gods from Lovecraft's writings.

Re: Priests and Mages in the same setting
 

Assuming a monotheistic paradigm with a benevolent god, there are a few options. As already noted, you can reskin the entities involved ("demons" actually being an unfallen subtype of angels - I recall in Chrno Crusade it's stated that the demons are actually servants of Heaven with the purpose of punishing evildoers - for example), ban the "evil" spells, or have the evil spells be things that are used as temptations; after all, if the benevolent god is also omnipotent (implied by monotheism), they've already allowed Evil to exist for some purpose unfathomable to mortals, so allowing such spells wouldn't be out of question.

If you tone down the omnipotence (which might just be another of those "unfathomable" bits), it may be that your god doesn't have the option of taking granted power back, and those that use their divine magic for wicked ends are simply acting without permission.

And also keep in mind that, in many cases, what matters is what one does with a spell rather than what the spell is. Summoning a demon in order to deliver punishment to said demon for their own wicked deeds (or even to redeem the demon, if that's possible in your setting) - or use it to appropriately punish a particularly vile evildoer - probably would be considered acceptable. Raising an army of skeletons from the local graveyard in order to protect the descendants of the bodies' owners (who still live in the town) may similarly be considered acceptable. If you cannot think of any situation where a particular spell could be used for good, it may be appropriate to ban it, but otherwise it can be justified to be in the priestly repertoire, even if the above ideas don't work for you.

Re: Priests and Mages in the same setting
 

I don’t quite follow how a pantheon answers the question. Why would any god want their priests to summon demons or create undead? The setting is more or less pulp fantasy, but I have a problem with gods that are straight up evil. Dangerous? Certainly. Best kept at a distance, propitiated rather than actively worshipped? Absolutely. The gods of plague, famine and similar come to mind. But as I said, straight up evil gods give me problems unless the cosmology incorporates Good and Evil as fundamental forces.

Re: Priests and Mages in the same setting
 

I mean, it depends on what you mean by undead, but it sounds like a really useful thing to me, and power is power. Make a deal with me, and I'll bind your soul to a temple and you will live as long as the temple stands? That's a great deal for both sides. Servants who can walk under the water? great. Your loyal servant isn't going to die of old age? fantastic, you can keep him forever.

Demons have a lot of baggage and limitations, but they still represent power, and power is useful, you just have to be careful.

Re: Priests and Mages in the same setting
 

The obvious answer, if you want priests to be able to raise undead and summon demons, is to posit that such are not evil. Undead are easy - the bodies of the dead that have been animated by magic, either via binding spirits into them (in some cases, possibly the original owner of the body) or using some other form of animating force. That's no more evil than turning an animal's bones into tools, clothing, tents, etc. Now, I could see a position where doing this to the bodies of sapients is considered evil, but undead can be made from animals (corrupt priests might do it to sapients, however, abusing their Gift).

For demons, as already noted you can just make them a different flavor of divine servitor. But if you do want them to be evil, and presumably in opposition to the gods (who appear to be related to natural processes), a natural option is to steal from Judeo-Christian concepts and make them rebellious/fallen divine servitors, those that have cut ties from their masters. In that paradigm, the ability to summon demons is actually a case of glitching or hijacking the Gift - they still have a divine spark of sorts, making them possible to summon just as proper servitors are, but their own corruption twists the process into something different, something the gods never intended (or did if going the "a god's mind is unknowable to mere mortals" route).

Re: Priests and Mages in the same setting
 

If objective Evil doesn't exist, then necromancy isn't objectively Evil. (Yes, this is a tautology.) Some deities might be perfectly okay with raising corpses and it might be a rite of their faith. This is not a problem - it only looks like one because "undead are evil" is the default assumption in fantasy.

Now, demons are another story - but honestly, if objective evil doesn't exist and demons do, then you need to define what demons are in your setting. (This is a flaw in the default GURPS magic system, because it got rid of Gygaxian alignment but kept Gygaxian demons.) If demons are "just" dangerous extradimensional beings, though, then they probably have their own gods who can be worshipped and called on.

Also, just because there aren't gods of evil, and there isn't an objective standard of morality, doesn't mean there aren't gods who are, from any reasonable human standpoint, evil. Most of the Olympians come to mind, especially Zeus - but not Hades, he's a pretty cool guy except in the Persephone story.