I like the idea that Clerical magic is inherently different from Wizardly magic. It makes sense at a basic level given that while nothing aside from losing the intellectual capacity (i.e., Intelligence) to memorize and cast spells can actually take the Magic User's spell casting ability away from him, a Cleric's god DOES NOT have to grant him spells. that is, coming directly from the god worshiped, if the PC fails to behave in accordance with the belief system of his Deity, then he should lose his ability to cast the Clerical spells the god bestows.
[NOTE: I found the 1st Edition Spells on a website for easy reference when we started playing this game (
http://pandaria.rpgworlds.info...ules/adnd_spells.htm) and note that they provide the following at the beginning of the Clerical spells list, which sort of underlines that there is a moral obligation related to spell use by Clerics that does not exist in the same way for Magic Users:
The reversal of some spells might well place the cleric in a questionable position with respect to alignment. The use of spells which promote weal must be shunned by evil clerics in many cases. Likewise, spells which are baneful may be used only at peril by clerics of good alignment. Incautious use of spells will change the cleric's alignment, if such usage continues unchecked, and it is up to the player to guard his or her character's alignment with care. In any event, the cleric must decide which application of a reversible spell will be used prior to learning it i.e. it is not possible to have one spell both ways. In like manner, the mere request for a spell (or its opposite) through prayer will not guarantee that the spell will be given to the cleric. As the spell level becomes higher, confidence will decrease that that deity will concur.]
This doesn't mean that morals and ethics don't apply to Magic Users, this is what Guilds and other mundane organizations are supposed to be providing/ensuring (this is also where witchhunts, etc. come in to play), but it does mean that their spellcasting is reliant only upon their own training and innate capability to cast. Whereas a Cleric's is entirely based up his standing with the Deity granting the spell.
So, as long as the game is being run and played properly then either making it that Divine Magic is not affected by Magic Resistance
OR making Magic Resistance specific to types of magic (i.e., Non-Divine or Divine) would be reasonable. That said, since the latter is not implicit already in the rules and stats of Monsters, et al. it adds a layer of complication, and the former might unbalance the system?
In other words, this is exactly the sort of reason I hate each edition of D&D. Please don't misunderstand me, after 36 or so years since being introduced to AD&D and through it rpging I have a sentimental affection for it and the highest regards for Gygax and Anderson and everyone else that created the original system. HOWEVER, since those days as rpg systems have become ever more sophisticated there are systems that manage this sort of stuff elegantly and effectively without accretion like this adaptation would effectively be.
Thanks for letting me get that off my chest.