Slither interaction

[The Total Package]

Can the spell Slither grab incorporeal creatures?

[Finoan]

There is definitely some ambiguity here.

The Incorporeal trait prevents corporeal creatures from attempting strength-based checks against them. So you couldn't Grapple an Incorporeal creature to apply the grabbed condition.

But Slither is a spell, not a corporeal creature. And none of its checks are strength-based. So the Incorporeal trait doesn't explicitly forbid it from working.

Strict RAW shenanigans aside, I would still not normally allow spell effects to cause conditions that are duplicating the effects of a strength-based check like the grabbed condition.

[Errenor]

Yeah. If it were at least a force effect, but it's not. And of course it doesn't say it overrules incorporeal. So I'd say the spell was not tuned for this and doesn't grab.

[Baarogue]

The incorporeal trait doesn't confer immunity to the grabbed or restrained conditions at all. The spell is described as creating "snakes made of shadow" and causes its effects based on a reflex save, so doesn't run afoul of incorporeal's limitations on str based checks. The mechanics and the fiction both support it working. I see no reason or justification to deny it arbitrarily

Take note that the specific incorporeal creature you use it on may affect the answer. If grabbed or restrained are on their immunity list, then that's final. They may also be resistant or immune to the damage, though that doesn't affect the condition effects

[Theaitetos]

RAW yes, incorporeal creatures would be grabbed by Slither.

If you want to explain it with flavor: Slither is a Shadow spell, that means it uses entities/energies from the Netherworld (formerly: Shadow Plane), which serves as a conduit between the Universe and the Void. Shadow (the one the snakes are made of) is partially incorporeal as well, is a perfectly reasonable take.

If you want incorporeal creatures to be "resistant" to it, but not fully immune, you can base it on the amount of damage the Slither inflicts: if the piercing damage is able to penetrate their damage resistance - as incorporeals usually have Resistance All - then they would be grabbed, otherwise not. That would be a middle way.