Invulnerability represents certain creatures' resistance to nonmagical weapons; it is often found on highly magical creatures like angels (Harbinger), and can be granted with the spells Stygian Skin and Invulnerability.
A creature's invulnerability value will replace its natural protection value against nonmagical attacks if it is higher. If a creature's invulnerability value is less than its natural protection, it will have no effect.
It is a useful ability for thugs that want to survive against swarms of mundane troops, but does nothing to protect them from counterthugs or elites with magic weapons.
Sources of Invulnerability
Temporary Invulnerability is mainly a Death effect:
The Stygian Flesh Bless
points of Invulnerability to Sacred
units; it requires 5
on your Pretender, and that they're on the map.
points of Invulnerability can be applied with the water of the River Styx. For this, the Stygian Skin
spell at Alteration Level 4
casters transmute regular water into Stygian Water to apply it to themselves, while the Stygian Rains
spell at Evocation
Level 7 lets 32
casters pay 2 to make the Styx rain on the entire battlefield.
points of Invulnerability can be self-applied with the Invulnerability
spell, a Level 5 Alteration that requires 3
Level 6, 4
mages can spend 25 to create a Robe of Invulnerability that also provides 25 points.