ToME: the Tales of Maj'Eyal

So if mindstars typically do either Mind or Nature damage, why do they have armour penetration as a stat? I'm playing a mindstar Marauder and I'm not sure if the armour pen is useful or not. I've found one or two rare mindstars which do physical damage, but they mostly do mind or nature.

I assumed that armour only applies to physical damage, but the fact that mindstars have ARP makes me question that thinking.

Armor applies to melee and archery attacks regardless of damage type. However, it does not reduce the damage taken by Earthen Missiles or other physical damage spells.

Thanks, that's very helpful. Not exactly intuitive that armour could reduce melee elemental damage but doesn't apply to physical spells.

How does armour apply to on-hit effects such as +5 (fire) damage? or do on-hit effects bypass armour?

Those bypass armor as well.

So basically any proc (like arcane blade spell proc) bypass armor while any type of direct melee/ranged damage are blocked. Nice to know, thanks!