What's a fair price for instant death when a certain condition is fulfilled?

[awesomenessofme1]

This isn't a huge deal, as it will be exclusively for NPC use, so the point value doesn't really matter. It's more of a thought experiment.

Here's the basic parameters I'm trying to simulate:

A group of people who used to be dead are being preserved through supernatural powers. This is channeled through a glass bead embedded at the point where their spine connects to their skull. It's beneath the skin, but outside the bone. If you know where to look, a simple cut and pull can remove it. If this bead is removed, they die instantly, no chance to resist, no questions asked.

What's a reasonable price for this? My initial thoughts are to base it off either Dependency or Terminally Ill with a Mitigator.

[Aldric]

Terminally Ill will probably not kill you fast enough even if you remove the mitigator.

A Rare constant Dependancy would give you about 150 points, and will still not kill you right away if you lose the item.

Being Unnatural and instantly dropping dead at -HP would help shorten that time, but it's still not instant and we're already at the 200 point mark.

[awesomenessofme1]

Originally Posted by Aldric

Terminally Ill will probably not kill you fast enough even if you remove the mitigator.

A Rare constant Dependancy would give you about 150 points, and will still not kill you right away if you lose the item.

Being Unnatural and instantly dropping dead at -HP would help shorten that time, but it's still not instant and we're already at the 200 point mark.

Technically, Terminally Ill at -100 is just "Up to one month". A nanosecond is technically "up to one month". But I think it might be a bit underpriced that way compared to Dependency.

[Aldric]

Too bad you can't buy down your HP to 0, buy them back up to a desired level with a gadget limitation, it would actually do exactly what you need. Lose the item (have it removed or damaged) and your HP drop to 0, instantly killing you.

[Pursuivant]

Originally Posted by awesomenessofme1

A group of people who used to be dead are being preserved through supernatural powers. This is channeled through a glass bead embedded at the point where their spine connects to their skull. It's beneath the skin, but outside the bone. If you know where to look, a simple cut and pull can remove it. If this bead is removed, they die instantly, no chance to resist, no questions asked.

Not to sound dismissive, but how is this different from an ordinary human's vulnerability to a targeted attack which kills by severing the spine at the C-1/C-2 vertebrae?

A sword slash which hacks through the neck is going to kill whether it's by severing vital nerves and blood vessels or by crushing the magic bead. Ditto for surgical procedures designed to kill rather than heal.

If they can be killed by severing their link to the ambient mana then your NPCs have Dependency (Mana (Common), Constantly) [-50].

If they can't die except by knocking them unconscious and surgically removing the bead, that's Unkillable I.

If they are super-vulnerable to thrusting/impaling or crushing attacks to the vertebrae at the back of the neck, call it a quirk, "Additional Vital Area."

[malloyd]

Originally Posted by Aldric

Too bad you can't buy down your HP to 0, buy them back up to a desired level with a gadget limitation, it would actually do exactly what you need. Lose the item (have it removed or damaged) and your HP drop to 0, instantly killing you.

I think that's on the right track. It's actually quite closely analogous to some robot builds - they "actually" have quite a low number of hit points (maybe 0, however many it takes to pull the bead) which is their "real" body. They happen to also control this bioshell/corpse that has some different number of hit points, but they don't actually "die" if you destroy that.

[Flyndaran]

That looks like a nice way to avoid the "abuse" of a fragile character that could easily die from other sources getting the same points as a super tough character that's hard to kill otherwise.

[ericthered]

I like the build on Ravens 'n Pennies (its a blog by a gurps author). The article pulp hunters has templates for immortal for use in monster hunters campaigns, including one for "object based immortality"

Object-Based Immortality:
You gained your immortality thanks to an object. You must keep the object hidden and safe as its destruction results in your immediate and messy death.
Hard to Kill 1 [2]; High Pain Threshold [10]; Regeneration (Regular) [25]; Regrowth [40]; Unkillable 1 (Achilles Heel, Damage from loss of object, -10%) [45]; Weakness (Loss of object; 1d/second; Quickened, +120%) [-22].

You want the weakness at the very end. It won't result in an INSTANT death, but its pretty close, and you're taking shock penalties in the mean time.

[David Johnston2]

Originally Posted by awesomenessofme1

This isn't a huge deal, as it will be exclusively for NPC use, so the point value doesn't really matter. It's more of a thought experiment.

Here's the basic parameters I'm trying to simulate:

A group of people who used to be dead are being preserved through supernatural powers. This is channeled through a glass bead embedded at the point where their spine connects to their skull. It's beneath the skin, but outside the bone. If you know where to look, a simple cut and pull can remove it. If this bead is removed, they die instantly, no chance to resist, no questions asked.
.

That sounds totally impractical to exploit unless you've already disabled them.

[Varyon]

Originally Posted by David Johnston2

That sounds totally impractical to exploit unless you've already disabled them.

Depends on what options are available to exploit it. If the bead is fragile enough to shatter from blunt force trauma, it means you can one-shot them with a mundane punch, provided you aim it right. If it's indestructible - or if the amount of damage needed to destroy it would cripple and possibly kill the target - then it's at best a Quirk. If the target cannot be killed without removing/destroying the bead, that's an Achilles Heel on Unkillable 2 (possibly Unkillable 1, if you treat the "total body destruction" at -10xHP as sufficient to remove the bead).

In general, I think a hybrid of a few of the options mentioned works for a "kill switch" Disadvantage. To kill quickly with damage, use Weakness (Everything; 2 HP/second) [-150]*, Fragile: Unnatural [-50], and sufficient Reduced HP to drop your HP to 1 [variable]; these three together are the Disadvantage Kill Switch. Now, buy the item as Negated Disadvantage: Kill Switch with appropriate Gadget Limitations (and don't forget to include Unique). Characters with Advantages that would prevent the above from killing them (such as Unkillable 2/3) should take said Advantages with the same Gadget Limitation.

If the item is "stolen" (a literal kill switch would be approximated with Can Be Stolen) or destroyed, the character immediately drops to 1 HP. His Weakness is activated, and the first cycle drops him below -1xHP, causing him to die instantly thanks to Fragile: Unnatural.

*Going off of the values from Limited Defenses (which is what Vulnerability uses) to try to extrapolate the cost for Weakness (Everything). With Rare at -80% and [-10] for 1d/min, this implies a base cost of [-50]. Occasional -60% and [-20] for 1d/min is the same. Common -40% and [-40] implies a base cost of around [-65], while Very Common -20% and [-60] implies a base cost of [-75]. With Weakness (Everything), I felt it was appropriate to go off of Very Common, so [-75]. That's enough for 3.5/min, but we want at least 2/sec for instant death (technically, this would still be instant, due to GURPS having Weaknesses deal full damage at the start of the cycle; this would mean even the 1d/30 min level would work, but honestly I think of this more as a rounding artifact). Ghostdancer's Quickened is +20% per x2 speed (or per 1/2 time, depending on how you look at it). Going from 0.0583 HP/sec (3.5/min) to 2 HP/sec is around x34 to speed, or right around 5 doublings (which would be x32 to speed), for +100% and [-150]. Once could argue that this would still take a full second to kill the target, justifying buying up one more level to make the death instant, but I opted to go with [-150] instead of the resulting [-165] because it looks neater. Optionally, instead of reduced HP and 2 HP/sec (or 4 HP/sec for the [-165] version), you could instead keep HP where it is and adjust Weakness to deal 2xHP/sec (or 4xHP/sec for truly-instant). Above, an HP 10 character would be at [-218] before adjusting for the Gadget by the first method (or [-233] for truly-instant). By the second method, such a character would need x342 speed (x684 for truly-instant) for 20 HP/sec. That's closer to x256 than x512, so round down to x256 and 8 doublings for an end cost of [-245] ([-260] for truly-instant). To work this out for any arbitrary amount of damage, multiply needed damage per second by 60 and divide the result by 3.5; this gives you the needed multiplier.