Armor

Armor is a form of secondary Health available only to heroes, gained through certain cards and Hero Powers. Damage taken will always be deducted from Armor before Health. Only when a character has 0 Armor will they lose Health from a damaging attack. Armor can effectively extend a hero's Health far beyond the 30 points otherwise allowed. All regular heroes enter play with 0 Armor, although bosses and Tavern Brawl heroes often start with some Armor.

When present, Armor is shown on the centre right of the hero, just above the Health icon, set against a silver, unbroken shield.

Armor is most strongly associated with the warrior class, followed by the druid class. Notable sources of Armor include the warrior Hero Power Armor Up! and the druid Hero Power Shapeshift. Some cards have more novel relationships with Armor, such as Shield Slam, which uses a warrior's Armor to deal damage to a target minion.

Fixed bugs

 * It was possible to have 0 Health but 12 Armor as a substitute. Although it was hard to replicate, it made the player experiencing that in a glitched state where it cannot be interacted by any means of an effect.

Random effects denied the player, and minions couldn't be directed to attack the player in that glitched state, because they became unresponsive until they directed to attack a valid target like minions.

Strategy
While Armor serves as a substitute for Health, loss of Armor will not reduce the summoning cost of Molten Giant. Warriors with Shield Slam can likewise benefit from Armor more than from Health, and Armor is not affected by Alexstrasza's Battlecry, making it an effective defence against this card. A low Health or damaged status can also be useful for cards like Battle Rage and Mortal Strike.

For these reasons, Armor is generally considered to be superior to Health. Where possible, it is usually therefore preferable to take any damage before gaining armor, such as by attacking with your hero before then using Armor Up!. This way the player can benefit from Zombie Chow's Deathrattle, having its hero's health restored and keeping the previously gained armor.