Defense

Defense is one of the core attributes for characters in Diablo III. It governs the amount of damage a character takes from all attacks, physical and magical.

Defense is not the same thing as Armor. The terms are confusingly similar in Diablo III, but Armor is what armor items grant. e.g. a buckler might have 8 armor while a tower shield might have 200. Armor helps increase a character's damage reduction, just like the Defense stat does.

Attribute Design

All attributes have changed since their original conception. In December 2010 Bashiok made an announcement about these changes:

Defense: Decreases all damage taken

• This stat is separate from armor and resistances, each of which effects different damage types. This stat effects ‘all’ damage.
• This stat will allow players to control incoming damage rather than increasing health capacity, which is useful to reduce the need for health globes and pots, and allows players to double down on defense for survival focused builds.
• This stat is also useful for PVP, and likely will be valued in the arenas, but isn't tuned to be a 'PVP' only stat.
• This stat has no secondary effects.

More details on exactly how Defense will work in Diablo III are not yet known. What is known is that attribute points are not assigned by the player; they are auto-assigned. See the relevant section in the attributes article.

• Defense is a secondary attribute governed by Diablo II's Dexterity.

Defense vs. Armor

The terms were used interchangeably in Diablo II, but in Diablo III they mean different things. The key thing to remember is that in Diablo III, Armor works much like a resistance; it affects damage mitigation, not to/hit (as was the case in Diablo 1 and Diablo 2.) Higher Armor in Diablo 3 does not mean that your character gets hit less often. It means your character takes less damage per hit. This is one of the major changes to the combat engine in Diablo III, and results in characters taking constant, steady damage, rather than the D2 style of attacks almost always missing, but when one does land it does huge damage.

• Armor is a value on all types of armor items. More armor = more damage reduction, but a lot of Armor is required to see significant improvements.
• Defense is one of the four core character attributes/stats. It grows as your character levels up, and can be added as a bonus from items, gems, skills, and more.

Both Armor and Defense increase your character's damage reduction, but Defense offers much larger gains, per point. (But since high level armor items can have many hundreds of points of Armor, both values must be cultivated for long term success.

Armor vs. Defense compared with item bonuses. Shot from the Diablo III beta.

Development

Defense is a new attribute for Diablo III, comparable to the Armor bonus granted by Strength, though you should note that higher Armor has a very different effect in D3 than it did in D2. See Attack for more details on how Strength changed.