Attack Resolution

All attacks in Pillars of Eternity - no matter whether they're made with weapons, spells, or other abilities - go through the same attack resolution system. Each attack can result in a Critical Hit, Hit, Graze or Miss. The likelihood of each outcome is based on the difference between the attacker's accuracy vs the target's defense values and can be affected by various abilities.

Attack Roll
An attack roll represents your attempt to strike your opponent resolved by a single d100 roll (a number between 1 and 100). The attacker chance to roll Critical Hit, Hit, Graze or Miss is determined by the difference between his Accuracy value and the relevant defender's defense.

Target Defense
The Defense used against attack accuracy is determined by the type of attack:
 * Deflection against direct melee and ranged attacks
 * Fortitude against body system attacks like poison and disease
 * Reflexes against area of effect damage attacks
 * Will against mental attacks

Attack Outcomes
According to attack roll value one of four attack outcomes willl take effect:
 * Miss meaning attack has no effect
 * Graze meaning -50% damage or duration
 * Hit meaning standard damage and duration
 * Critical Hit meaning +50% damage or duration

The Default ranges for an attack roll are:
 * 01-15 = Miss
 * 16-50 = Graze
 * 51-100 = Hit
 * 100+ = Critical Hit

Attack Result
As can be seen, Critical Hit is not possible at all (the attack roll is a number between 1 and 100). However, these are only the default ranges used when accuracy and target defense values are exactly the same. Each point of difference between accuracy and target defense "shifts" all ranges by one point.

Therefore, if the Accuracy and defense values are balanced, the majority of attacks wind up being Hits or Grazes. On the other hand, when the difference is extremely high, possibility of a Miss or a Critical Hit can sometimes be negated entirely (while always allowing the possibility of a Graze or a Hit at the extreme ends of the spectrum. ).

See Chart: (credits to Theurgist from forums, see post)



When damage is an element of an attack, it is always the thing that is modified. If it's a "flat" status attack(like a Stun), duration is modified.

Examples
Examples for different accuracy and target defense values (without abilities that modifies default ranges):

(Accuracy - Defense) + Attack Roll = Result

Class Influence
Certain classes have abilities that shift the default ranges for attack roll (e.g. rogues Dirty Fighting), have inherent Accuracy bonuses (fighters had an inherent Accuracy bonus with all melee weapons early in development, was cut) and/or start out with an advantage in certain defenses (e.g. barbarians have higher starting Fortitude defense and rogues have higher starting Reflexes defense).

Accuracy and defenses increase as you gain levels. The character defense increases uniformly every level for every class. If you advance a level all defenses will increase by 3 points, regardless of what your class is. On top of all this, both Accuracy and defenses can be boosted with Attributes, Abilities, Talents, spells and items.

Conversion of an attack Outcome
Certain weapons, Abilities and Talents grant an additional roll after the accuracy roll that allows for the Outcome of an attack to be converted to a better one. Only ONE conversion can occur per attack, per "direction" (aggressive/defensive), meaning that it is NOT possible for a Graze to be converted to a Hit and then to a Critical. Multiple bonuses to the same conversion type are additive, e.g. using a Flail with Confident Aim results in a 50% Chance to convert a Graze to a Hit. Conversion rolls also can be defensive, converting an incoming Attacks Outcome to the respective lower Tier.

Weapon Affixes that grant a conversion roll modifier
 * Reliable: +20% Graze to Hit
 * Predatory: +10% Hit to Crit
 * Durgan-Refined: +20% Hit to Crit

Weapons with above mentioned Affixes:

Items with an aggressive conversion roll modifier:

Items with a defensive conversion roll modifier:

Abilities that apply an aggressive buff with a conversion roll modifier:

Abilities that apply a defensive buff/debuff with a conversion roll modifier

Talents that grant a Passive conversion roll modifier (all aggressive):

Critical Hit Multiplier
Weapons that modify the critical hit multiplier

Items that modify the critical hit multiplier

Talents that modify the critical hit multiplier
 * The Merciless Hand +0.3
 * Dungeon Delver +0.1