Armor class (AC) is a number representing a creature's ability to avoid being hit in combat. An opponent's attack roll must equal or exceed the target creature's AC to hit it.
AC = 10 + armor bonus + shield bonus + dodge bonus + natural armor bonus + deflection bonus + other bonuses
The average, unarmored peasant has an AC of 10.
AC types[]
- armor bonus - provided by armor slot and bracers slot (bracers only; gloves provide deflection)
- shield bonus - provided by shield slot
- dodge bonus - provided by boots slot
- natural armor bonus - provided by amulet slot
- deflection bonus - provided by all other inventory slots
Only dodge bonuses stack, up to a maximum of +20. For all other types of bonus, the single highest modifier is applied.
A polymorph form may convert some item AC bonuses to separate deflection AC bonuses that do not stack, though the item property haste will still give a +4 dodge bonus if it is included in the merge. All other item AC bonuses it will ignore. The polymorph may also give a dodge bonus and, more rarely, a deflection bonus to AC. All of this AC pertains to the corresponding +20 cap and only the dodge stacks. There also may be a change to the AC from the new size modifier according to the size of the polymorph.
Armor class guide[]
As above, there are several types of armor class in Neverwinter Nights; some will work together (i.e., stack) and some will not. Knowing what stacks and what doesn't can often mean the difference between useful equipment and useless equipment.
Below are 6 AC categories; the 5 that NWN uses (natural, armor, shield, deflection, dodge), and one extra "other" category to hold the bonuses that do not fit into the 5 base categories. All these categories will stack together, and ultimately sum together to form a character's total AC.
Sources of natural AC[]
These will not stack with each other; the highest one is used. **
- epic spell: epic mage armor (+5)
- item: amulet AC bonus (+1-20)
- spell: mage armor (+1)
- spell: barkskin (+3-5)
- spell: shadow shield (+5)
Sources of armor AC[]
These will not stack with each other; the highest one is used. **
- epic spell: epic mage armor (+5)
- item: armor AC bonus (+1-20)
- item: bracers AC bonus (+1-20) (same item slot as gloves)
- spell: mage armor (+1)
- spell: magic vestment (+1-5)
Sources of shield AC[]
These will not stack with each other; the highest one is used. **
- item: shield AC bonus (+1-20)
- spell: magic vestment (+1-5)
Sources of deflection AC[]
These will not stack with each other; the highest one is used.
- epic spell: epic mage armor (+5)
- item: gloves AC bonus (+1-20) (same item slot as bracers)
- item: ring AC bonus (+1-20)
- item: belt AC bonus (+1-20)
- item: helmet AC bonus (+1-20)
- item: cloak AC bonus (+1-20)
- item: weapon AC bonus (+1-20)
- item: dusty rose ioun stone (+1)
- spell: shield (+4)
- spell: mage armor (+1)
- spell: shield of faith (+2-5)
- spell: protection from alignment (+2 versus selected alignment)
- spell: aura versus alignment (+4 versus selected alignment)
- spell: magic circle against alignment (+2 versus selected alignment)
- spell: undeath's eternal foe (+4)
Sources of dodge AC[]
These will stack with each other, but is limited to a +20 maximum dodge bonus. *
- effect: haste (+4)
- epic spell: epic mage armor (+5)
- feat: bard song (+2-7)
- feat: divine shield (+1-20)
- feat: defensive stance (+4)
- feat/skill: mounted combat (+1 for every 5 points of ride skill check above 10)
- feat: shadow evade (+1-4)
- item: boots AC bonus (+1-20)
- spell: mage armor (+1)
All dodge AC is lost when caught flat-footed (even if the character has the uncanny dodge feat).
Other sources of AC[]
These are all individual sources, and stack together with no restrictions.
- ability: dexterity (+1-122, but limited by the armor's maximum dexterity bonus) *
- feat: armor skin (+2) **
- feat: battle training vs. giants (+4 against giant-type enemies)
- feat: bone skin (+2-16) **
- feat: dodge (+1 against current target or last attacker) *
- feat: draconic armor (+1-8) **
- feat: expertise/improved expertise (+5/+10)
- feat: mobility (+4 against attacks of opportunity) *
- feat: monk AC bonus from level progression (+1-8) **
- feat: monk AC bonus from wisdom (+1-122) **
- feat: small stature (+1, or more generally the size modifier)
- item: armor base (+1-8) **
- item: shield base (+1-3) **
- skill: tumble (+1-8) *
* The dexterity bonus to AC, dodge, and tumble AC benefits are lost when caught flat-footed, but the uncanny dodge and defensive awareness feats allow the dexterity bonus to be retained.
** The armor, shield and natural AC provide no benefit when subject to a touch attack.