Psi Sense and Passive Abilities

[Daigoro]

It says, "whenever anyone near you uses [psi]," which makes no reference to that use being active or passive.

I believe the designation of being active or passive is important for GURPS game mechanics in terms of what counts as a maneuvre, how many actions a character gets and so on. I would be leery of reading that as having a wider, more general, in-universe meaning.

[Plane]

Originally Posted by Daigoro

It says, "whenever anyone near you uses [psi]," which makes no reference to that use being active or passive.

I believe the designation of being active or passive is important for GURPS game mechanics in terms of what counts as a maneuvre, how many actions a character gets and so on. I would be leery of reading that as having a wider, more general, in-universe meaning.

P163 has the contrast basically under in two spots:

1. the left column under (2.)

If it's passive then only "special senses" can detect it. Active use abilities need to specify at least one of the four normal senses (vision/hearing/touch/smell) which can detect it.

Taste doesn't get mentioned so I'm thinking that folds into smell or is considered too niche.

2. the middle column under "Obvious Effects"

"isn't totally passive" is one of the three possible ways for avoiding this standard requirement:

buyer must describe a set of effects that are obvious to one or more ordinary human senses

The other two are:

* isn’t based on a .. trait with explicitly invisible effects (including "mental-influence advantages" with two examples given: Mind Reading and Mind Control)
* isn’t enhanced with No Signature

The phrasing could be summarized like this:

"If A isn’t E, isn't P and isn't N, then B"

Since A being B requires it not be E or P or N, any of E/P/N being true would mean that A is not B.

Lacking "No Signature" is the most obvious: that is all advantages by default, you just need to know if it's a modifier.

"Explicitly invisible" is a little subtler: it that truly meant to be "invisible" (can't be seen) or perhaps more broadly undetectable to other senses too?

"Totally passive" is also a little subtler: the use of the word "totally" implies some kind of higher requirement, like it acknowledges you can have ~sorta-passive but not TOTALLY~ abilities (like Aura)

P164 also uses the "totally":

Abilities that aren’t currently in use, or totally passive ones, are never detectable except with a specialty of Detect specifically designed to identify individuals who have those abilities.

The issue I think is maybe we don't necessarily have the clearest idea for every advantage which ones are "totally passive" vs perhaps just "semi-passive".

Armor of Faith (MH1p43: No Signature -20% in 2011) vs Force Dome (PAWSp9:Visible-10% in 2016) versions of DR would be another fun thing to dabble in.

I think that contrast could be resolved in remembering there's actually 2 forms of No Signature on B106, which gets weird because without separate names there might be some guesswork as to which one is intended when NS is listed. It's weird since it's written for an "attack", not DR.

My guess for how this could make sense is that if we assume wild DR functions like having the 1st type of No Signature: "almost completely unnoticeable" rather than "utterly undetectable by normal means, but leaves a magical or psionic trace"

I would think the latter might actually fall under one of the -5% "countermeasures" aspects of those power modifiers... but maybe not?

Armor of Faith taking -20% could be intended maybe to make it the "best of both No Signatures" where it's both utterly undetectable AND doesn't leave a trace?

Whereas Force Dome could basically be removing the "almost completely unnoticeable" inherent aspect of DR by making it translucent, which is not near enough to "completely" to be called "almost".

P103 also mentions that: "If the ability is obvious and traceable, buy the enhancement twice"

I'm thinking maybe we could call these something like "No Obvious Signature" and "No Traceable Signature" ?

That said I think the -10% mana-sensitive with the -5% countermeasures built into it makes "Detect Magic" stuff able to detect force walls... so does the -10% "Mystic" power modifier give that to Mysticism Abilities except Armor of Faith because it cancels that out?