Psychic Signatures
 

The use of powers leave traces. In Psionic Powers, they're called "Psychic Signatures". On p. 20 of that book, it adds the enhancement Low Psychic Signature. There are also ways given to Hide a Signature, and to Detect them.

I'm curious though, why was a "High Signature" or "High Psychic Signature" limitation not added? Was it a concern over abusability? An oversight? Or some other reason?

EDIT:
Obviously it's easy to just make your own: -5% for every +2 to detect. Still curious why it wasn't ever included anywhere.

Re: Psychic Signatures
 

There's no such thing as ordinary "High Signature" for non psychic powers either. I think that's meant to be covered by "Nuisance Effect: Obvious" -5%.

Re: Psychic Signatures
 

Joseph Curwen?


GAHHH!

Re: Psychic Signatures
 

I know, although there's no reason why it can't be even more obvious than -5% worth. Each +5% Low Signature represents a -2 to be detected, it would be a nice symmetry if it went the other way too, each -5% High Signature representing a +2 to be detected.

Also, a question regarding signatures - are they any rules or guidelines for the range / area effect of psychic signatures, or is that something left up to the GM on a case by case or campaign by campaign basis?

EDIT:
Forget the question about range / area effect. Stupid question.

Re: Psychic Signatures
 

That may be the oddest comment I've seen tonight.

Re: Psychic Signatures
 

Ah, I see my reputation has preceded me. Have any essential salts to trade?

;-)

Re: Psychic Signatures
 

Gyahhhh!

Back to the grave, foul sorcerer!

Re: Psychic Signatures
 

There is, actually. Once you are pretty sure to be detected by a typical psychic there's no further disadvantage.

Re: Psychic Signatures
 

Psychic signatures are detected via Detect, and that has penalties for range. Higher psychic signatures would cancel out those penalties, so your use of your power can be detected from farther away.

From 100 yards away (assuming their Detect doesn't have levels of Increased Range), they're at a whopping -10 to their Sense roll, and 100 yards isn't really all that far away. But if your power had High Signature -25%, giving a +10 to detection, they'd be just as likely to detect your power being used from 100 yards away as they would be to detect a normal, regular psychic signatured power at 2 yards away or less.

Being detectable from far away could be quite a big deal, depending on the campaign.

Re: Psychic Signatures
 

These both sound right. The appropriate Detect at short range is already reasonably likely to notice a normal signature, so (IMO) a more easily noticed one would have to be pretty obvious to rise to the level of a minor Nuisance Effect. I'm having trouble envisioning an effect based solely on noticeability that would justify more than a -5% NE... maybe in a game where detection (using Signature Sniffer and Psi Sense) is a major theme :?

Re: Psychic Signatures
 

You're right - at short range. But see my post above. At 100 yards, there's a -10 penalty to standard unmodified Detect. The more levels of what I call High Psychic Signature you have on your ability, the easier it will be to detect at long range. I would think that any game where Psi Sense and Signature Sniffer are significant as psychic residue senses would justify taking -5% for each +2 to detect. Imagine the equivalent for ordinary mundane signatures - at higher signatures, things like huge flashing lights, storm clouds, thunder claps, etc. The higher the signature, the easier it will be to notice from farther away.

Re: Psychic Signatures
 

Because Nuisance Effect is an existing limitation, and that's really what this is. Now, realize that such a limitation would not be worth -5% per +2! It's a mistake to assume that everything in GURPS mirrors on both sides of the line. For starters, a Nuisance Effect which makes your power nearly impossible to hide is only supposed to be a -5% limitation! So I'd say that +10 to your psychic signature is worth -5% and +20 is -10%. I wouldn't allow any further levels, because there's no way this should be more limiting than Visible.

Re: Psychic Signatures
 

I agree that it shouldn't be more limiting than Visible... if you could reasonably compare their effects. Visible's description is "a manifestation that makes it plainly obvious to everyone nearby" (emphasis mine). Range penalties to Sense rolls would apply to that. Rightfully, Visible should have levels too, to make it more "obvious" to people from farther away (adding bonuses to their Sense rolls to reduce long range penalties).

If you believe I'm wildly overestimating the problems and limitations that being more easily noticed from farther away would bring, please let me know, because it's entirely possible I'm just missing something. But to my mind there was a good reason that the rules give a -10 penalty at 100 yards (-16 at 1000) to Sense rolls (and it's not just about realism). Having your powers produce such strong signatures that they are noticed without penalty from 100 yards away seems worth -25%, and from a whopping 1000 yards at no penalty seems worth -40%. Not only does it definitively guarantee that people at ground zero won't really stand a chance of missing it, but people from all around will notice too.

If I was a psi with a power that gave a bonus to detection of +10 or +16 (or even lower bonuses), I doubt I'd use my power much (and I think my choice to limit my usage would scale with the magnitude of my signature), especially if I was in a world where psi activity is actively sniffed for and the psis hunted.

Re: Psychic Signatures
 

I was going to use the word "blatant", but changed it to "pretty obvious" to avoid off-putting connotations... your suggested levels make me think I should have just left it in :) Yeah... the fact that your particular ability is easier to spot than others doesn't amount to much when you think of Visible. Being detectable from further away isn't going to be as much of a problem if you have the distance as a buffer.

Re: Psychic Signatures
 

That makes assumptions about how big a factor distance really is. In real life, it's a big one. In a world with psionics, maybe not so much. People can have abilities that can work across vast distances (to affect or stop you from a distance), or they can Warp or have super-speed capabilities (to physically get there fast), remote senses (to see who caused the ruckus so they can come get you later, after they undo what you did when you're gone potentially).

A power that makes a flash of light is Visible and a big nuisance. A power that manifests as a several yard wide swirling vortex is harsh. A power that makes the noise of a gunshot is awful. A power that manifests with the effect of equivalent to noticeability of a bolt of lightning combined with a thunder clap heard for miles around is just terrible. Degrees, each one more limiting than the last, and IMO, with the limiting effects scaling with the magnitude of the signature based on how far out it can be detected.

Re: Psychic Signatures
 

Considering that making a rocket-powered-woosh noise combined with a big jet of light-emitting fire is only worth -5%, I think all three of these are still the basic Nuisance effect - and that flash of light isn't "turned on a flashlight" but more like "700 watt photographers flashbulb of augh I can't see my eyes oh my precious eyes" [1]


[1] Why yes, I've had my husband completely blow away my night vision with an overpowered studio flash once, why do you ask?

Re: Psychic Signatures
 

A 700 watt photographer's flashbulb is not a bolt of lightning (especially if it comes with the thunder clap too), or those big search lights like the one they use to call Batman (from potentially miles away). Those other things are more disadvantageous, more limiting. A flash that is blinding from 2 yards away will barely be a twinkle and won't register to anyone 100 yards away except on a really clear moonless night with no street lights.

Oh, and sorry about your night vision. :-)

Re: Psychic Signatures
 

The ability to generate a bolt of lightning is a power in its own right. If it's going to be that blatantly obvious at a distance, up close it's going to be devastating to anyone nearby, and therefore costs points — it's not a limitation.

Re: Psychic Signatures
 

I'm not talking about a real bolt of lighting. It won't cause damage, not even blinding. I'm talking about something (with the noticeability of a lightning bolt complete with thunder) that will be noticed for miles around. If your ability had a really high signature, such that it gave a +18 bonus to be noticed, then people 100 yards away (who suffer a -10 penalty to Sense rolls) will be rolling at +8, and people 5 miles away will be rolling at only -4 (compared to the -22 penalty that basically makes it impossible normally). To me that's worth -45% (-5% per +2 to detect), because everyone who can notice will notice for miles around, and can then act against you or against what you've just done with your power. The number of people that can notice will be growing I think geometrically as the "range" of the signature increases (the bonus to others' Sense rolls increases).

Re: Psychic Signatures
 

It's not because once your ability becomes that loud it doesn't really matter if the bonus is +10 or +20; either way you aren't going to use it unless you don't care if you are detected or not.

Re: Psychic Signatures
 

You might be right.

But I know the number and kinds of things I'd be willing to risk getting heard or seen doing or saying in a 100 yard radius (+10), especially in a pinch, are much greater than the number of things I'd be willing to risk getting heard or seen doing or saying in a 2.5 mile radius (+20).

And this ignores the fact that psychic signatures aren't like mundane signatures. Not everyone can notice them. In a world where there are maybe 50 psis, all capable of Psi Sense, living in a given large metropolitan area, my odds of not getting "heard" in a 100 yard radius are a lot better than not being heard in a 2.5 mile radius. I'd risk the +10 much more often than I'd ever risk the +20.

EDIT: I'd also like to point out that for each +1 on the Size and Speed/Range Table there are increasingly large gaps in distance. To me this covers entirely the possible "diminishing marginal cost" of "loud" powers.

Re: Psychic Signatures
 

In a world with supernatural abilities, the onus is still on the person with the supernatural ability to cough up the points. Joe Catburgler doesn't suddenly develop a disadvantage "Noisy Catburglary" because someone else on Earth buys the ability Detect Catburglary (Reflexive, Reliable +40) and Warp (Accessability: only to sites Detected with Active Catburglary).

Except possibly Enemy, if Anti-Catburglar-Man then takes it upon himself to teleport to the location of every act of catburglary to blow an airhorn or something.

This is one of the reasons why your Nuisance Effect: "really noisy psychic signature" is probably worth less than a comparable visible or audio signal - but as a GM I'd suggest that, for the same price as regular audio-visual noisiness, the alternative that it's so "noisy" that even the non-psychics get a psychic "ping" about you.

Re: Psychic Signatures
 

If we assume that only 50 individuals in the city can even detect your "High Signature" power, then it should be worth next to nothing. A gunshot on a crowded street (ie, "normal" signature for an Innate Attack) could be heard by scores or hundreds of people. A psychic signature would need to cover the entire city to be similarly "noticeable" if psychics are that rare.

Re: Psychic Signatures
 

A few psis that might "hear" you out of a possible 50, depending on their abilities and power levels, could be a lot more dangerous to you than scores of mundanes hearing you firing a gun (or the psi equivalent). They can affect you from a distance with their powers, you won't know what powers they can bring to bear against you, they might be able to get to you faster (Warp or super-speed or Projection), possibly harm your ability to use your power or undo what you've done afterwards, or they can use remote senses to "keep their eye on you" after you've caught their attention (in which case your privacy is shot to hell). And that doesn't even cover the possibility of randomly placed government psi-detectors placed secretly throughout the city.

Re: Psychic Signatures
 

If you discharge a firearm indiscriminately within city limits (especially in view of others) you'll soon have law enforcement or even the military breathing down your neck. Basically, my point is that High/Low Signature shouldn't be worth more points for something that fewer people can detect, even if those few people may be powerful and dangerous.

Anyways, I think I'll follow the good Reverend's suggestion of -5%/-10% for a +10/+20 to detect.

Re: Psychic Signatures
 

I don't think it's about "number of people who can detect", it's about how often your use of your powers will be detected, and maybe most importantly, how often you'll stop and think "hmmm... maybe I shouldn't use my power, stealth and subtlety are what's needed now, not signatures every psi in a 5 mile radius can detect".

But to each his own. I'm going to go with -5% per +2 because there's symmetry in that, and because it leaves the scale open-ended, and in the setting I'm planning it'll be important to operate with a soft touch.

I take and agree with RPK's point that not everything in GURPS can be mirrored on the other side (disadvantages and limitations costing the same as their advantage and enhancement analogues often may not work or be balanced), but I personally think this is not one of those times. I don't just believe that because it feels right to me, but because the ranges associated with the penalties to Sense rolls grow wildly as they progress; if they grew linearly I might be a lot more inclined to agree but I feel the chart's progression is justification enough for my position. The difference between 0 penalty and -1 penalty is only a yard, whereas the difference between a -10 penalty and a -11 penalty is 50 yards, for instance, and Low Signature levels really only stop people from noticing anything if they're right on top of the situation at ground zero. I'm honestly kind of confused by the brilliant focus and attention to detail put into things like Psi Sense, Signature Sniffer, Hide Signature, et al, if for the most part, it's all for rather short range effects that you have to be actively looking for.

Re: Psychic Signatures
 

It occurs to me that magical powers might also have signatures. Those attuned to magical signatures might, for example, find that a place "reeks of demon" based on its magical signature. If an individual mage becomes well-known enough his own magical signature may be recognizable so that attuned people know whether he cast that spell or whether he has cast a spell in the vacinity.

Of course, most mages are not well-known enough that just anybody attuned to magic can recognize their auras. It would usually require acute personal experience with that mage, as an ally or an enemy. (Demons are a different story -- you could usually tell there were demons around without having to know what specific demon it is).

Re: Psychic Signatures
 

From my reading of the Low or No Signature section on p. P103, I've always assumed that each kind of power source leaves "psychic signatures", traces that can be detected via a sense like Detect Signatures of This Source (or abilities like that). I certainly agree magic (it's specifically mentioned) will do that, but I think any power source that doesn't have No Psychic Signature: Undetectable +25% built into it will leave traces behind. I know using the word "psychic" feels more for psis, but really I think it's a generic enough term (and it is the official term as per Psionic Powers, p. 20) - after all, it's not "psionic signature". In any event, I agree with you and I think for mages having high psychic signature magic would be just as bad, if not much worse, as it is for psis.

You could always put levels of either to increase or decrease the signature of Magery so all your spells leave less of a trace behind.

Re: Psychic Signatures
 

While I'm generally leery of attaching modifiers to Magery that affect the properties of spells (rather than access to spells or casting method) in this case I like it.

The only other way I can think of to do this would be using the rules to add Enhancements to spells (Thaum p39). Hence, attaching No Psychic (or Magical) Signature to a spell would penalize the casting by -5. That seems kinda steep... but maybe it's appropriate.

Re: Psychic Signatures
 

Huh - I hadn't seen that rule in Thaum, thanks. It certainly is less of a blunt force instrument than adding it onto Magery.

Is there an official stance on adding general modifiers to Magery to affect the properties of spells? I can definitely see the need to be leery - and certainly nothing grossly abusive like "Reduced Time" or "Extended Duration" should be applied, I should think.

Re: Psychic Signatures
 

In general, such modifiers are forbidden, just as you can't add Armor Divisor to Striking ST or Weapon Master and have it apply to melee attacks. This was one of the key motivations of Imbuements, giving PCs the ability to add enhancements to traits not actually represented by powers. I think it's best to consider Magery to be an enabling trait like WM or TbaM, giving you access to cinematic skills, rather than being a power in its own right.

Re: Psychic Signatures
 

Makes sense.

Re: Psychic Signatures
 

How long are psychic signatures meant to last?

Is it like "seeing" a flash or some dazzling lights (metaphorical equivalents, of course) to the Psi Sense / Signature Sniffer, and then they're gone? Or do they linger over time gradually weakening until they're finally no more? Or are these details left to GM fiat?

Re: Psychic Signatures
 

Good point. The normal signature of an Innate Attack is compared to a gunshot, which has an immediate flash and report, and leaves behind certain material evidence (the residue of the gunpowder, the bullet itself, damage to the surroundings etc). But all of that requires special skills and equipment to detect and analyze. I'd treat the normal Magic or Psychic signature similarly - it takes special gear and techniques (Alchemical kit, Postcognition, etc) to find and interpret. A good application of High Signature would be a magical residue that can be spotted by anyone with Magery, or psychic reverberations that echo in the mind of Telepaths and Espers. This would probably be a -5% limitation (Persistent Signature) in addition to any modifier for Low or High Signature for the actual use of the power.

Re: Psychic Signatures
 

I like that idea of Persistent Signature - the "echos" thing could be a big deal, well worth the -5%. Telepaths could "hear" the initial burst of psychic signature, and then follow the "echos" back to the scene of the "crime" (or whatever it was, the use of the power).

Re: Psychic Signatures
 

it's not really an assumption, so much as the way things are. Being far away from someone you don't want to be near is naturally preferable to being close to them. That sensitives might notice you from further away still doesn't put them in a position to do something about it. That takes other gear, or points sunk into other abilities. And pricing limits (indeed, traits and mods in general) can't be done on the basis of what might be the case in a particular game, but must be done with an eye to the Universal, so that they will likely apply to the most settings. GMs are then free to tweak things as necessary to make things fit their own vision. If, as the game and RPK, are telling us, more obvious signatures aren't such a big deal, it seems most reasonable to me to assume that there's a case for the position, and work with that assumption to ensure that 'blatancy' does not become overly important. AIS, detection doesn't put them there, and even Precise, Nontargeting means they still need to pinpoint you with another sense to attack, which presumably will be more difficult if they sensed you from miles away.