Sexual Energy

Sexual Energy is an item of Dependency (B130) specified for two monsters in GURPS Horror:
#Succubus GURPS Horror, p.66
#Ardat-Lili GURPS Horror, p.93
==Dependency Math==
Like "Leeched HP" (P96 defines as Common for Trigger) the -30 when nightly (daily = x3) means the base cost of -10 is "Common". Unlike Infants' Breath it does not appear to be illegal, but if it were then this would instead make sexual energy "Very Common".
==Leech v Leech==
The common element of both forms of Leech which both demons have is that the restore HP to the user. Both have Accelerated Healing (1:1 not 1:3 ratio) and Leech 2 (2 per second) however there are differences in what they actually take from victims:
*Succubi take FP until it's down to 0, then take HP
**Steal FP is not to be confused with Heals FP or Only Heals FP: "steal" refers to what is taken from a target, not what is restored to user
*Ardat-Lili always take HP
There's also difference in attack prep time:
*Succubi have TET 10 meaning they need 8 minutes of continuous ready maneuvers before each attack
*Ardat-Lili have an instantaneous Leech, but it's Link+10% to an Affliction with 1 minute of prep time. Since it's not "Immediate Prep" they can still attack instaneously, just not continuously.
There's also difference in attack circumstance:
*Succubi's Leech has Contact Agent (must touch skin, or possibly have skin-to-skin contact since Leech may be considered in the Touch-based Malediction category) plus Requires sexual intimacy (unclear if that requires just one or both parties and how broad the acts may constitute)
*Ardat-Lili's Leech has no limits except being male-only so it can work through clothing. The linked Affliction OTOH does have contact agent. This means if they drain a man through clothing they'll get the HP but he won't be vulnerable to Ecstacy.
==Leech as Daily Dose==
This seems to be part of a broader pattern where "HP or FP gained via the Leech advantage counts as common for fulfilling Dependency or Trigger requirements"
It does not likely meet the descriptor "touch or carry an object" meaning it would fit one of these two descriptors:
*regularly ingest a substance
*spend time in an environment
Either may relate to the attack Leech which has the enhancement Steal FP and Accessibility of Requires sexual intimacy.
The "ingest a substance" interpretation could refer to the FP gained after a successful attack, which due to TET 10 requires a series of 1x2^9 readies (1s-2s-4s-8s-15s-30s-1m-2m-4m-8m) before the attack maneuver. This is the most difficult, since any interference would prevent fulfillment.
The "spend time" interpretation is a bit looser, as even interruptions prior to the 8 minutes would still count as time in the environment of sexual energy, so failures could still add up to time in the environment. However this could take a longer period of itme.
The fluff "drain their essence through the sex act" probably favors the harder 1st interpretation where energy/essence is the HP that Succubi or Ardat-Lili gain after a successful 8 minutes of prep.
Normally the touch/environmental interpretation could be a drawback (time spent must be equal to damage interval) which is 60 minutes required. This is still longer than the 8 minutes required to leech 1 FP, assuming it succeeds. But it still might be beneficial if the 8 minute prep was failed for some reason.
One such reason could be that Leech inherently requires a grapple or ongoing contact.
This is the Steal (Other Score) mentioned on P96. Since it is +50 and not -25 this means that HP is stolen after HP reaches 0, explaining the fluff "often killing them". Since a Succubus recovers HP from the points stolen, this presumably allows her to recover HP lost due to not being able to fulfill her Dependency. The Nightly rate (alternate phrasing likely due to being Nocturnal) would be equivalent to Daily which is 1 HP per hour after missing a daily dose.
One thing that is not entirely clear is whether or not the "sexual intimacy" accessibility is required just when using the attack maneuver at the end, or if the conditions of accessibility must also be fulfilled for the preparatory ready maneuvers.
*this is similarly unclear for the grappling requirement: if the grapple is needed just during the end attack maneuver, or also for the 8 minutes of readying.
Succubu have two Malediction afflictions GURPS Horror, p.12 they can use with Concentrate maneuvers: Nightmare and Sleep. Sleep gives at least 100 minutes which would be enough to fulfill the 1 hour requirements of environmental/item contact for Dependency, or twelve 8-minute periods of preparing to Leech.
The "deep slumber" is not sleep as the ability implies but actually Unconsciousness which is worse: they cannot be roused. B429 explains unconsciousness but doesn't seem to cover sleep.
Despite that, Nightmare says "only on sleeping subjects". But it presumably applies to unconsciousness too.
==References==
category:rules