Re: How Low Can You Go: The Minimum Magic Required
other things that were considered occult lore included the particulars of human perception. most people still do not understand how this works and the best experts on the subject are mostly stage magicians. It is there understanding of how your perception works that permit them to do there stage tricks.
Re: How Low Can You Go: The Minimum Magic Required
Basic utility now and then is your bare minimum while still being useful. Little or no combat magic.
It's the 3.5 equivalent of casting a few level 1 spells a week. Maybe level 2 eventually. Utility spells are hard to use at all, so you'd have to have a high number of spells known, just a low total number of spells.
I've seen something like this done in Lone Wolf with willpower points. The spells were also super versatile and general in their application. Still somewhat powerful though not nearly D&D level. You could do something similar but even weaker. Or instead of general purpose spells just give out a large number of clearly defined weak spells. Willpower was also used for the rough equivalent of a will save or battles of the mind, so if you burnt too many you left your mind vulnerable.
So something simple to implement just as an example: You get a dozen or so WP. They heal 1 per day. Rare items might heal 1 more. You may cast any 3.5 sor/wiz cantrip using 1 WP. But if you go nova you'll have a sucky will save. After a few levels you get 1st, 2nd and at high level 3rd level spells. 2nd and 3rd level spells cost 2 WP each. Btw in terms of utility 3.5 spells have a big jump at level 2 instead of level 3 as it is with combat spells, so it works out. Since you know so many different spells and get to cast so few, utility spells to solve oddball situations are your best bet. Like mage hand, unseen servant, Tenser's floating disk and spider climb. The combat spells might even be banned for flavor and to avoid giving players traps. Of course in your gaming system you'll make up your own spells and tweak the points a bit. But you get the idea.
Healing could be handled via potions & magical medicines, basically alchemy and/or (magic) herbalism. If not rest and mundane means most of the time.
Re: How Low Can You Go: The Minimum Magic Required
Just look at Merlin, he may be the gratest wizard of history and very rarely he used magic.
Great wizards don't do magic willy nilly, they do most things in a mundane way, they are wise and are able to see beyond and they know that using magic is not free it always has consequences.