Armor and defense mechanics

Armor and Defense are two stats that influence how damage is reduced. This article goes into depth about how these two stats interact with one another, and how effective each type is against different damage sources.

Defense reduces the incoming damage by a flat amount. Armor reduces the incoming damage (after being reduced by any Defense) by a percentage amount. ''e.g. Exploding fireball deals 50 damage. Having 1 defense and 8% armor from having the Grit robe will make it deal 1 less damage, and then 8% less damage after that.'' The formula looks like: (Damage - Defense) * Armor * Elemental Resistance.

Decimal amounts are rounded up in favour of more damage, e.g. 10.1 calculated damage becomes 11 actual damage. Note that elemental resistance is multiplicative with armor, unlike armor which is additive with itself. '''PENDING TESTING: Elemental resistance from multiple sources - multiplicative or additive? '''

Testing
Armor and Elemental Resistance interaction tested in co-op:
 * Player 1 has patience (4% armor) and Resolute Svalinn
 * Player 2 has grit (8% armor, 1 defense)
 * Player 2 uses exploding fireball on player 1. It deals 36 damage. 50 * 0.96 * 0.75 = 36.
 * Player 1 gives player 2 Resolute Svalinn.
 * Player 1 uses exploding fireball on player 2. It deals 34 damage. (50 - 1) * 0.92 * 0.75 = 33.81, which rounds up to 34.
 * Players drop Resolute Svalinn and repeat...
 * Player 1 takes 48 damage. 50 * 0.96 = 48.
 * Player 2 takes 46 damage. (50 - 1) * 0.92 = 45.08, which rounds up to 46.

Additional Notes
Theoretically, it is possible to achieve 148% armor: Neve's Emerald (21%), Improved Grit (12%), Tortoise Shield (12%), Armor of Resolve (20%), Calcifying Bonemail (20%), Golden Armor of Envy (16%), Armor of Greed (16%), Euphie's Shawl (5%), Heavy Travel Jacket (1% per relic held, 10% max), Memory Chainmail (16% if attacks are of the same type as the last 3 that inflicted damage) It is pointless to go beyond 100% as you will always take at least 1 damage (unless you guard or evade.)

Relics and Arcana that provide shields (as indicated as a blue meter above the player's head) are not affected by damage modifiers. This is also applicable for Double Trouble, Double Toil and Nog's Heavenly Boots, which would normally make you take increased damage but the shield always takes unaltered damage, making shields really effective after acquiring those items.

Double Trouble, Double Toil and Nog's Heavenly Boots appear to double damage before defense is applied, and thus also before armor and elemental resistances are applied too.
 * This is subject to more testing at the moment