[Basic] Advantage of the Week: Permeation

[johndallman]

Permeation [5 to 40] is an exotic physical advantage, usually supernatural or a super-power. You can pass through barriers of solid material, specified when you buy the advantage. The price depends on how specific the material is, and how rare it is as a barrier: the advantage has its own table for this. This advantage appeared at GURPS 4e, as a generalisation of the 3e advantages Move Through Ice and Transference.

You don’t disturb the material when you pass through it, or leave a tunnel. You just “soak” into, and out of, the surface. You aren’t Insubstantial, and don’t acquire any new forms of movement. You can be affected by any attacks that can reach you inside the material, and you’re vulnerable to attacks with the material, unless you buy that separately. If you want to be able to see through the material, or breathe while inside it, buy those abilities separately. You can take Can Carry Objects (+10% to +100%) to let you carry things, such as your clothing, or Tunnel (+40%) to create a tunnel. You can’t cause explosions by dropping carried objects (see p. B75), nor can you Tunnel through living things.

Powers adds a good deal: the ability to permeate through multiple materials, paid for like Alternative Abilities, or “Everything,” two enhancements for melding yourself with things you can permeate, a limitation for the maximum thickness you can get through, and alternatives, like Burrowing, Insubstantiality, or Diffuse with Infiltration.

In GURPS supplements, Permeation is fairly common among elemental creatures, and supernatural horror parasites. Infinite Worlds: Nightreign has a monster that got its Permeation approved by a very helpful GM, while Power-Ups 4: Enhancements has a version of Affects Others that lets you apply this advantage to other people.

Examples: Permeation (Flesh) is only [5] and if the GM will let you buy (Cloth) along with it, allows significant impromptu body horror. Permeation (Glass) [10] with Finite Thickness (one inch, ‑30%) and Can Carry Objects gets you into almost any TL6 or later mundane building, unless it has wired glass.

What have you got through with Permeation?

[Christopher R. Rice]

I've allowed Permeation for Electricity + Meld to phase into a power grid for electrokinetics.

[Pursuivant]

It's got the advantage of being a cheaper version of Insubstantiality that provides many of the mobility benefits but without the defensive benefits.

It's quite useful for modeling creatures of air, granules, or liquid that can penetrate various materials, assuming that you don't want to buy Injury Tolerance (Diffuse) with the Infiltration enhancement. The Takes Extra Time limitation is good for modeling slow permeation, like a liquid creature gradually seeping through semi-porous material. Assume that objects with gaps large enough to allow large particles to get through are Occasional, Liquid- or fine granule-permeable materials are Common, and gas-permeable materials are Very Common.

I have no idea why Permeation and Tunneling are separate traits. Effectively, Tunneling is Permeation (Earth and Stone) but with movement limitations, the Tunneling enhancement, and a hypothetical "Requires Skill Roll to create a stable tunnel" limitation.

Tunneling is the cheaper option if you want to bore through earth or stone relatively slowly and leave a tunnel which others can use. For example, Tunneling + Tunneling Move 5 is 55 points. By comparison, Permeation (Earth and Stone), with a -10% limitation for Requires Skill roll, and a +40% enhancement for Tunneling, costs 52 points, or 92 points if you can carry up to Heavy Encumbrance.

If you've got any level of super-speed, however, Permeation (Very Common) + Tunneling + Can Carry Objects is the better deal, particularly if you just want to permeate limited types of materials or don't plan to carry a lot of weight.

For example, Enhanced Move 3 [60] + Permeation (Very Common, Enhancements: Up to Light Encumbrance, +20%; Tunneling, +40%.) [64] = 124 points and Move 40 vs. Tunneling + Tunneling Move 40 = 230 points.

Admittedly, Tunneling lets you bore through anything at Move 80 while carrying up to Heavy Encumbrance, but given that Warp costs "just" 100 points, it's not exactly competitive. (But then again, neither is Permeation beyond a certain point. If you want to instantly move from one side of a thick barrier to the other, buy a limited form of Warp.)

[Kallatari]

In my campaign, I've added the following enhancement:

Cosmic, Works Against Attacks: While your Permeation is on, attacks made of the material you are permeable against will pass through you completely without harm - and may hit anything behind you, depending on the nature of the attack. This does not protect your gear and equipment (unless you also have Can Carry Objects). Cost: +300% enhancement

I found it was easier to plug in a Cosmic enhancement to Permeation than to mess around which a whole bunch of limitations on Insubstantiality that significantly altered what Insubstantiality was made for.

Yes, it does go against the typical GURPS design choice of not having any absolute immunity to damage traits, but it's a Cosmic enhancement and requires specific GM oversight to allow, so I'm fine with it and will only allow it in campaigns I want it to appear in (just as I would any trait).

And it does have drawbacks compared to actual physical immunity. Someone like Superman who is immune to bullets (high DR) could step in front of his teammates and take the hits, with the bullets hitting him and not harming anyone else. Other the other hand, someone with Permeation to bullets couldn't protect anyone or anything else. I therefore wouldn't allow a Supe Brick-like character to buy this trait as a means of achieving damage immunity against something as it really doesn't match the desired effects.

[RogerBW]

I thought I'd used this in my conversion of the empathic powers from Dark Conspiracy to GURPS 4e – but it turns out I took Injury Tolerance (Diffuse) with Infiltration (from Powers p. 53) as a slightly better match to the original effect. I agree with Pursuivant that there seem to be quite a lot of traits which do basically similar things.

[awesomenessofme1]

Meld is a really fun enhancement. I built a super with Permeation (Sand; Can Carry Objects, +10%; Meld 2, +300%; Super, -10%), for a total cost of a very affordable 40 points. With that, she can instantly teleport or have effective Clairsentience across an entire desert area, or even travel between any two ocean beaches on the planet in one second. It's... honestly a little bit broken, not gonna lie, but "cross the entire planet" is explicitly called out as possible if you have it for Earth, so it's definitely RAW.

[ericthered]

This advantage is really fun but really wacky. I don't think I've ever used it, outside of maybe a parasite build.


EDIT: wait, I take it back. I'm using it on the big bad that will destroy the world in a current game, and its possibly its most distinguishing characteristic. How did I miss that?

[naloth]

Originally Posted by awesomenessofme1

Meld is a really fun enhancement. I built a super with Permeation (Sand; Can Carry Objects, +10%; Meld 2, +300%; Super, -10%), for a total cost of a very affordable 40 points. With that, she can instantly teleport or have effective Clairsentience across an entire desert area, or even travel between any two ocean beaches on the planet in one second. It's... honestly a little bit broken, not gonna lie, but "cross the entire planet" is explicitly called out as possible if you have it for Earth, so it's definitely RAW.

This ability is powerful for 40 points, but only when you can somehow get to use it.

Furthermore, IME the melding to hide, spy, rest is much more powerful than the travel aspect. Sandy beaches only is a pretty severe restriction as a destination and you also have to start on one. It just wouldn't have been that useful in many games I've played in. Besides, if it a GM didn't want you to get to a particular beach, the GM could rule that rocky range separates it from other beaches.

[David Johnston2]

Originally Posted by awesomenessofme1

Meld is a really fun enhancement. I built a super with Permeation (Sand; Can Carry Objects, +10%; Meld 2, +300%; Super, -10%), for a total cost of a very affordable 40 points. With that, she can instantly teleport or have effective Clairsentience across an entire desert area, or even travel between any two ocean beaches on the planet in one second. It's... honestly a little bit broken, not gonna lie, but "cross the entire planet" is explicitly called out as possible if you have it for Earth, so it's definitely RAW.

That sounds wrong. Surely the beaches would have to be contiguous to permeate from one to another.

[ericthered]

Originally Posted by David Johnston2

That sounds wrong. Surely the beaches would have to be contiguous to permeate from one to another.

Its sand, not beaches. I don't know enough about ocean geography to say if that will let you traverse the world or not. Its great in some deserts as well.