Trying out for a game here with this theme got me interested in the concept, but when I looked around at the available material I noticed there wasn't a lot of information on the subject. I guess it's understandable given the nature of Dungeons and Dragons but I'd like to explore the subject further.
Originally Posted by AugustusGloop
It wouldn't be a problem in a barbaric society where'd noone knows anything about arcane magic, but what about the world that was very magic savvy? A world where professionals with divine magic and a lot of experience would be hunting you? How would you hide your magic items and powers?
Y'mean like Mage: The Ascension
from White Wolf? Point being, from whom are you hiding your magic? Hiding magical effects from those who know it exists is hard
. Really, really hard. A divine "witch hunter" will be more
familiar with the workings of divine magic than any arcanist. You might fool the rubes with a few ad-libbed "dominus ominus" and sketching a cross at the end of your somatic gestures, but you won't fool a priest ... let alone someone trained to recognize the ways witches try to conceal their vile arts.
A lot of it boils down to system. In the afore-mentioned Mage, as long as a PC performed "sympathetic" effects, the mortals of the world were none the wiser. It was only when they use Vulgar effects that mortals start asking hard questions. Paradox didn't care either way: it knew that sudden failure of the power lines that electrocuted the assassin was, in fact, a lightning bolt.
Hiding magic in a game based on D&D's 3.5 rules gets harder ... but there are rules in later supplements that allow for it. Reference the Beguiler class and several skill tricks. In a pinch, you could even use Bluff vs Spot, Spellcraft, or even Knowledge (Religion) to try to pass your spell off as a prayer.