Targeting hit locations with magic is fairly straightforward in most cases: If the damage type of the spell can’t target the location – then the spell can too. But what if you want to target a hit location with a spell that doesn’t allow it or specify a damage type (like many spells in GURPS Magic)? What about other magical systems? The following list is by no means exhaustive, but I hope you, dear reader, get some use out of it.
GURPS Magic System
Most spells have a damage type (Fireball is burning, Ice Dagger is impaling, etc.), but some spells have no damage type (Dehydrate), or are just weird (Sunbolt). To get past this, the GM may allow you to use the Adjustable Spells rule (GURPS Thuamatology, p. 39) and trade 4 FP and -4 to skill for the ability to target hit locations. This is essentially adding Selective Area/Effect (p. B108) to your spell.
Dungeon Fantasy Caster Power-Up
Precise Blast
Whenever you use a damaging spell or one that afflicts a condition the GM feels could be used to target body parts (using Decapitation to remove a hand or leg instead of the head), you can decide to spend an additional 4 FP and take a -1 to skill. If you are successful you can target a hit location you otherwise would not be able to. Do keep in mind that this is pointless for some spells, especially those that cause Fatigue loss.
Perks: Unique Technique (Precise Blast) [1].
Techniques: Precise Blast! (A) Exorcism-1 [9].
Ritual Path Magic
This one is pretty easy, just add Selective Area to the Damage or Affliction modifier for +4 energy. It’s probably going to only make sense for Internal Damaging effects, but external ones are possible too. Adding an enhancement like that to affliction is a bit iffy, but for this one particular enhancement to do this one thing, I don’t foresee any issues.
Path/Book Magic
Due to the overall lack of overt damaging effects for this style of magic, I’d probably consider using the rules for bog-standard magic or just creating a new ritual:
Twist The Hand, Bend The Bone
Effect Shaping: Path of Health-5; 1 hour; paralyze one body part per full multiple of its hit location+2 you inflict (e.g., if you succeed by four, you can paralyze one of the victim’s arms)*.
Energy Accumulating: 10 points, +2 per -1 of penalties for a paralyzed limb (as above).
You can paralyze a target’s limbs. You can target one limb per full multiple of its hit locations that you succeed on your roll. So if you succeed by eight, you could target both arms, or an arm and a leg, and so on. After you make your skill roll, roll a Quick Contest of Wills with the target, success means you’ve actually inflicted the paralysis, failure means he resisted.
* GMs may allow locations like Vitals or Eye to be targeted, if so just treat as Malaise (GURPS Thaumatology, p. 149).
Picking Over The Bones
There is no way I could possibly cover all the variations of magic systems that GURPS has to offer, for the most part, just see how you add enhancements and add Selective Area. Some might not need them and for others, it would just be redundant. That said, if you got a pet system, you want me to poke at – reply below.