Slumber and outsiders - are they immune?

[Agata]

Outsiders can sleep but don't need to. Are they immune to a witch's slumber hex?

[Jeraa]

Agata wrote:

Outsiders can sleep but don't need to. Are they immune to a witch's slumber hex?

No, they aren't immune.

Constructs, dragons, oozes, plants, and undead are all specifically stated to be immune to sleep effects (in the case of dragons, immunity is only to magical sleep effects). As the slumber hex is stated to work as sleep, that also makes it a mind-affecting compulsion effect. That also makes vermin immune.

[Magicdealer]

They're not immune to a slumber hex, or other sleep effects by default. There is no entry under outsider traits that would give it to them unlike, say, undead traits which specifically list sleep as something they're immune to.