Prerequisite(s): Holy Aura.
This spell is fourth of four armor-class-boosting spells that both clerics and priests may learn between level 1 and level 50. Characters of other classes, except for druids and (at lord tier) paladins, will never be able to learn it. It is included in Aegis but not in Awen. Its AC bonus may be modified by its caster's choice of worship (an atheist invincibility will give the target an extra -100 AC).
We are considering changes to the way the invincibility spell works: the intention is for it to perform as an Aura. This means, that invincibility can only be cast on oneself, but it will affect all members of the casters group in the same room. Each additional invincibility aura in the group will lead to a diminishing, but existant, additional protection.