Hardened Chassis

Your exterior is so tough that only the strongest of weapons can fully damage it. Choose one type of damage among bludgeoning, piercing, or slashing damage. You gain resistance 3 to that type of damage. This resistance does not apply if the weapon or attack is adamantine.

Enhancement Your chassis gets even tougher. Choose one of the following benefits: you gain resistance 3 to all physical damage, or your chosen resistance increases to a value equal to half your level (minimum 3). This resistance is still bypassed by adamantine.