SRD:Ring of Energy Resistance
From D&D Wiki
|This material is published under the OGL|
Energy Resistance: This reddish iron ring continually protects the wearer from damage from one type of energy—acid, cold, electricity, fire, or sonic (chosen by the creator of the item; determine randomly if found as part of a treasure hoard). Each time the wearer would normally take such damage, subtract the ring’s resistance value from the damage dealt.
A minor ring of energy resistance grants 10 points of resistance. A major ring of energy resistance grants 20 points of resistance. A greater ring of energy resistance grants 30 points of resistance.