Shared HP Pool Advantage

[smathers]

Is there an OOB Advantage that would allow two creatures (such as a Mage and Familiar) to share a Hit Point pool for damage purposes?

I don't recall coming across it even in 3rd edition, but I wanted to check the hive mind to be sure.

[ericthered]

There is at least some ability to do so via dupes, but the rest of the advantage isn't a superb fit for a familiar.

[JulianLW]

Pyramid 3/75, Christopher Rice's "A Familiar Path," might give you some ideas for how to build this.

[RedMattis]

I suggest basing it on Ally + Sympathy Limitation, -25%.

Just set the HP of both creatures to the same value. Sharing a hp-pool seems like a feature with comparable pros and cons. A Healing spell on one heals the other f.ex.

[Plane]

Originally Posted by smathers

Is there an OOB Advantage that would allow two creatures (such as a Mage and Familiar) to share a Hit Point pool for damage purposes?

This isn't purely out-of-book but it's pretty canon-adjacent IMO...

1) either you or your familiar buy a "Vitality Reserve" per http://www.sjgames.com/gurps/faq/FAQ4-5.html#SS5.1.5

2) buy "Affects Others, 1 person, +50%"

The precedent for use of the AO enhancement for Energy Reserve (and thus Vitality Reserve since it's based on that) is in Pyramid 3/1 under "Improved Zombie" which Kromm wrote in his "Necromantic Tools" article.

Kromm gave it "Area Effect" too. Without that, you would need to remain in physical contact to share the advantage: AE allows it to be shared at range w/o maintaining contact.

Sharing VR or ER is simpler than trying to apply Affects Others to HP or FP.

You probably COULD but it could lead to complicated record-keeping since those base stats have things which take effect at certain %s and as access fluctuated to your ally and the ability came and left, you'd need to be constantly recalculating what % you were at instead of having a fixed cutoff.

Another approach might be to buy Vitality Reserve and use the "Drains Familiar" limitation from Dungeon Fantasy, except instead of draining FP you say it drains HP.

[Balor Patch]

Extra HP 5 (Granted by Familiar/Master -40%, Drains Familiar/Master -50%) [5] & [5]. When one loses HP so does the other, and the HP go away entirely if they are distant from each other.

[Plane]

-50 includes the -40, doesn't stack to -90 per Kromm

so instead of buying +1 to HP for 2 points, each could spend those two points on +2 to HP with a mutual injury caveat. Perceiving it as a "shared pool" is basically conceptual.

For recovery I think you would use whichever is lower of either's healing rates?

This is probably not as attractive as ER that drains since you have control over that (it isn't drained like FP, doesn't get hit first to stop loss of FP)

Your approach (both taking 'drains X' limitations) suits OP's request better.

With your approach (advantages which vanish when other is not in range) it still begs the question of whether or not dependent energy pools remain full or empty out when turned off.

This does make me wonder though... if you have an ally who has an ER that drains YOU, isn't that some kind of disadvantage?

Taking that limitation on the ally's ER would lower their point value and make them cheaper allies (or allow them to have other abilities without costing more), which is actually beneficial.

It's actually like having a disadvantage (like a dependence) built into allies as a metatrait... Sympathetic Injury being similarly mixed.