Armor rating

Armor rating (AR) is a statistic that determines how much damage a creature will take from most sources of physical damage and elemental damage.

Characteristics
Armor reduces the percentage of certain types of damage done to a creature. In broad terms, every gain of 40 points of armor rating cuts 50% of non-armor-ignoring damage and every 40 points lost of AR doubles that same kind of damage. For example, creatures with an AR of 100 take half as much damage as those with AR 60 and twice as much as those with AR 140. Accordingly, it is critical for a character to use armor sets with the maximum armor rating possible.

Each piece of armor protects only one part of a character: a character with 4 pieces with AR 80 and headgear with AR 40 will take double damage any time they take a hit to the head; they will not have AR 360. However, bonuses from a shield, focus item, weapons, or skills are global; those will affect every hit, no matter where it strikes.

Each location has different odds to be hit. The chest has the highest chances (three out of every eight attacks), followed by the legs (two out of eight); the feet, hands, and head have the lowest chances (one in eight). Armor costs and bonuses reflect this, with the material costs and insignia bonuses typically tripled for the chest and doubled for the legs.

Armor ratings and stats vary according to a creature's profession. This means each profession will have a different maximum armor rating, different stats and different protection against various types of damage. See basic armor for more information.

The damage multiplier can also be found for non attack skills if the attacker is the same level as you with the equation



Overview
In general, physical and elemental damage is reduced by the target's armor rating. While the majority of attack damage falls under this category, a number of skills, especially under the Mesmer, Necromancer, and Monk lines, deal damage that ignores armor. All bonus damage from attack skills is armor-ignoring, so all Warrior and Ranger skills that confer +XX damage deal the specified damage regardless of armor level; the base attack damage inflicted at the same time as these skills is affected by armor.

Having 60 armor rating is regarded as the baseline, so a spell that reads "Deals 100 fire damage to target foe" would deal the full 100 damage to a foe with 60 armor but only 50 damage to a foe with 100 armor. The armor rating for creatures in PvE is dependent on level where the actual armor rating can be typically calculated by (creature AR = 3 * Level + Armor bonus), where armor bonus is profession specific. Many creatures in PvE do not follow this formula and may be significantly resistant or vulnerable to certain types of damage.

Note that some effects increase (Frenzy) or decrease (Dark Escape, Mantra of Flame) damage without modifying armor; these are effective against all damage regardless of whether it respects armor.

Armor penetration directly reduces the effective armor rating of the target, thereby increasing the damage dealt. For example, hitting a 60 AR target with 25% armor penetration will reduce the effective armor rating of the target to 45, thus increasing damage by approximately 30%.

Armor enhancing skills do not stack beyond +25 armor; without this restriction a player could easily acquire an extremely high armor rating making them nearly impervious to armor-respecting damage. A single skill can still bypass this cap, but using further armor-enhancing skills will have no effect. If several skills are used which bypass this cap (for example Kinetic Armor and Armor of Earth at high attribute levels), only the skill with the highest armor bonus will apply.

Armor tables
The table below lists how much damage you should take from normal attacks and spells.

The table below lists how much damage you should take from normal attacks and spells, based on a change in armor level. (E.g. if you had 60 armor and were taking spell damage of 100, how much damage would you take if your armor was reduced by 20? 100 * 1.4142)

The table below lists how much damage you should take from normal attacks and spells. It is an extended version of the first table, listed to show how the extremes of armor affect damage.