Currently staff on a Neverwinter Nights RP server that is based on a Roman-esque country run by Baatezu within the layer of Cania. Long long story, enough fiction behind it to fill several books, anyway that isn't the purpose of this post.
The issue the staff is currently arguing over comes down to how magic wll be handled on the server. It's much harder to have the mysterious "No one knows, it just is" that tends to surface more often than not in Planescape considering we have multiple DMs and many players with conflicting view points. So we require an ironbound staff ruling on how magic is handled, even if the PCs don't ever need to find out.
So the issue comes down to two major questions the staff is pondering even now as we speak in a staff meeting:
1) Is magic finite in Planescape, or is it infinite in amount. Can one continuously drain the magic from an area if such a thing were possible until one remained? Or would such an act continue on forever or until the object draining it reached it's full and exploded or similar.
2) Do deity, nature, and arcane magics come from different sources? And therefore are they of completely different spheres? Or does all magic regardless of type stem from the exact same place?
Those are the questions. If anyone can city Planescape books or passages that would be excellent and is really mostly what I'm looking for. Thank you for your time.
Re: #1 I'm not sure I understand the context of this question. Could you fill us in on that so we know exactly which set of logic rules to apply? What spells are you thinking of to drain magic?
Re: #2 - It's the standard difference between arcane and divine magic as in 3rd ed. Which is to say - not much. Deific/druidic spells come from the hands of gods or the belief in a faith creates it. Arcane magics come from using proper techniques within reality to cause changes (like physics in the real world helping you create working lightbulbs).
Planescape (traditional 2nd ed Planescape) has some oddities with divine magic on the outer planes based on how far away you are from where your god makes kip. Basically it cuts down your level based on how far away you are from the place. Context matters heavily for your caster for which Power they worship. Druidic magics treat the Outlands as their 'home'.
Arcane magics (traditional 2nd ed Planescape) require spell keys. Basically 'they don't work correctly unless you are carrying X item. This applies to specific spell schools.
Those rules are included as an option in our version of 3rd in the PSCS, but may otherwise be ignored. Personally - I wouldn't bother to apply this as it would require you to have effectively a lookup table for 'X god/spell = Y modifier'. You'd have to look it up for each option you include.
Your biggest thing to account for in Baator is that there is no Etherial plane connection. It doesn't work. It's just not *there*. So spells dependant on those connections just don't work. No etherial jaunt for example. This applies to all magics.
I don't have my books on hand so I'll see what I can find when I get to them.