Tough as Nails

Tough as Nails Passive Increases Armor by 25% and damage done with Thorns by 100%. After a while, the scars serve as their own layer of armor.

Tough as Nails is a Barbarian passive skill in Diablo III, unlocked at level 30.

In-game

Armor bonus is not multiplicative with other similar modifiers.

Barbarian Skills

Primary Skills
Bash • Cleave • Frenzy • Weapon Throw
Secondary Skills
Hammer of the Ancients • Rend • Seismic Slam • Whirlwind • Ancient Spear
Defensive Skills
Ground Stomp • Leap • Sprint • Ignore Pain
Might
Overpower • Revenge • Furious Charge • Avalanche
Tactics
Threatening Shout • Battle Rage • War Cry
Rage
Earthquake • Call of the Ancients • Wrath of the Berserker
Passive Skills
Pound of Flesh • Ruthless • Nerves of Steel • Weapons Master • Inspiring Presence • Berserker Rage
Bloodthirst • Animosity • Superstition • Tough as Nails • No Escape • Relentless
Brawler • Juggernaut • Unforgiving • Boon of Bul-Kathos • Earthen Might • Sword and Board • Rampage