[Christopher R. Rice]

Originally Posted by Icelander

Indeed.

I'm allowing 'enchantments' that are tied to the life force of a person attuned to them, i.e. "until the heart of John Thistlewaite beats no more". Haven't specified the exact energy, as this is background justification for how NPC magicians assisted PCs in making magical items they bought with character points at PC creation, but I want to make it fairly affordable. Of course, most occultists believe that tying ongoing magic to someone's life force will, at minimum, shorten their lifespan by draining vital energy every day (perhaps like smoking), and at worst, embroil those who embrace such magical workings in messy things like Destiny, Weirdness Magnet and supernatural Enemies, by making a person into an anchor or eddy in the preternatural tides of mana flow.

In 'realistic' terms, killing a person is usually simpler than getting royalty to pucker up and kissing amphibians, so while this is undoubtedly useful for adventurers (who tend not to care about their gear once dead), there is a metaphysical justification for making it reasonably energy efficient. Plus, of course, taking up a conditional magic slot and costing character points should serve as adequate balance against player abuses.

Cool.

Originally Posted by Icelander

While I'm not inherently opposed to using caster IQ, I categorically do not want to allow a caster to rely on it instead of the ST, DX and HT of the body that 'donates' the hand (or other body part).

It's a lot creepier and more flavourful for the caster to covet the beatiful hands of a concert pianist, for their delicate touch in performing surreptious sleight of hand, than to be essentially indifferent to donor Attributes and just as happy to take any old arthritic hand from a dying addict.

Either an average or the lower of caster's IQ or donor's relevant physical Attribute.

That's fair, but the guidelines to do something like this for RPM/RPM-like systems is p. 20 of GURPS Dungeon Fantasy 19: Incantation Magic..