Gaudivore

Gaudivores are creatures with the ability to steal joy and convert it to energy.
The Gaudivore meta-trait is described on page 12 of GURPS Horror. Despite being listed under "sample Afflictions" it is actually an Affliction Linked to Leech. It has some unique aspects.
==The components of the two parts==
Both Affliction and Leach have Link and Malediction. Affliction has Based on Will grating the primary disadvantage Killjoy with a secondary disadvantage of Chronic Depression (6). Leech has Accelerated Healing, Only Joy, Ranged, and Steal FP
==the key modifier==
Firstly, Leech has the Only Joy limitation which is absent on the H21 list for that advantage. It is interesting since Joy is somewhat hard to quantify.
The ability explains
:"This attack drains the target’s joy, transferring it to the attacker as FP".
This is strange because the ability doesn't mention the -20% Only Heals FP limitation...
It might have been intended that this was built into it, so that Only Joy is an additional -30% on top of it totalling -50%.
Joy might be intended to function like a Hazard, except "FP lost to unhappiness" is not a standard defined one.
==standard modifiers==
The Steal FP aspect is straightforward, the +50% is the same as the Succubus has (FP to 0 then HP). Same thing with Accelerated Healing, which just makes a 1:3 ratio into 1:1:
==Margin-Based==
It then elaborates:
:the attacker can steal total FP (or HP, if the victim is at 0 FP) equal to his margin of victory, at the rate of 1 FP per second after the attack, without needing to roll again. These heal his FP.
Normally, using a Leech+Malediction, a quick contest has to be won every singe second to drain them.
Basing total points stolen on a margin is seen elsewhere: Obligate Metuovore which is -50%. In that case it is a 1-sided MoF, not a MoV: the margin a Fright Check is failed by.
This appears to substitute a fright check for the Quick Contest Will v Will which both linked abilities use (introduced by Malediction: in the case of Leech this defaults to Will as a defense while Affliction took the "Based on Will" enhancement to shift it away from HT)
This is basically how the Margin-Based enhancement works for afflicting disadvantages, based on Secondary Effect, which this Affliction also uses (Killjoy > Depression)
==Marginal math==
Margin-Based from Psionic Powers is 3x cost for a leveled enhancement for which MoF/MoV levels actually happen, up to a maximum of 10.
*Metuovore is not exactly like that: there is no cap of 10 points mentioned
*Doleovore conversely can't have pain penalties go so high, the maximum is +6 for LPT and Terrible Pain.
*This is from Psionic Powers but it needs to be tweaked because 10 levels of Leech bonus is NOT possible, at least not for pain (it is for fear)
Assuming minimum Will is 3 (notably Fearfulness cannot buy Will below that) the maximum MoF is probably 15 points (rolling an 18)
*higher MoF seems like the only downside to Will 3, determining MoF and severity of failure, since actual failure isn't any more likely than with Will 4: both only succeed on critical successes
Pricing this on a higher possible range means it would go beyond merely 3x cost, maybe 4x.
The pricing scheme for Doleovore (pain) isn't based on resistance or margins at all and woudl need to be calculated totally differently but apparently works out to the same fina l one.
Knowing the Obligate limitation functions like an Accessibility on Leech's basic quantity:
this would be applied to the "value" or a stolen HP point
==Link==
Normally, you would make two quick contests (one for Affliction, one for Leech), they appear to be combined as a zero point feature, guaranteeing that FP is only gained if at least some joy is lost (Killjoy).
This is based on B106:
:If you link two attacks into one and give them identical Malf., 1/2D, Max, Acc, RoF, Shots, and Recoil, you can treat them as a single attack with one attack roll but separate rolls for damage.
==Safe feeding==
1-4 FP can be gained without inflicting chronic depression.
Category:Meta-Traits