A critical hit (or crit for short) is an attack that strikes a vital organ and as a result, may do additional damage.
How It Works
A critical hit occurs when an attack roll results in a 20, before any bonuses are applied - i.e., a "natural 20".
A critical hit will succeed in striking a target, regardless of the attacking creature's THAC0 or the target creature's armor class.
A critical hit can still be fooled by a Reflected Image or Mirror Image, and the critical hit can possibly just hit the image, but not the real target.
A critical hit doubles the weapon's base rolled Physical damage and any physical damage modifiers. Some examples:
- A critical hit achieved by a creature with no weapon proficiency with an ordinary arrow launched from an ordinary short bow will inflict 1d6 Missile damage and that number is doubled on a critical, if a 1 damage was rolled the critical hit will double it to 2 damage. The maximum damage possible from this bow and ammunition will be 12 missile damage with a critical hit.
- Minsc has a current strength of 19, ++ specialized in axe weapon proficiency, wears the Gauntlets of Extraordinary Specialization, and wields Hangard's Axe, which deals 1d6+2 slashing damage. The range of damage with all of these factors is 14 - 19 damage - therefore a critical hit's damage range is 28 - 38 damage.
So, to summarize, a critical hit will double the following damage sources:
- Base weapon physical damage (1d10+2 for a Two-handed Sword +2)
- Weapon proficiency bonus damage modifiers (+2 from weapon specialization, +3 weapon mastery)
- Physical damage modifiers from spells or equipment (+1 from Bless spell, +2 from Legacy of the Masters)
- Strength modifiers damage bonus (+1 damage from 16 strength, or +6 damage from 18/100 strength)
- The +4-damage bonus applied to a Racial Enemy such as the ranger class gets to choose, as well as from other select adversaries in the game.
- The bonus disadvantage opportunity damage applied to equipped missile weapon users attacked in melee combat range.
A weapon attack that applies some kind of non-physical extra damage effect, such as a bonus +1d4 Fire damage isn't doubled with a critical hit, or the +1 cold damage from the Varscona sword won't be doubled, nor will electricity damage from a Shocking Grasp touch attack or magic damage from a Cause Serious Wounds touch attack.
There is one exception and that is for the +10 Piercing damage from the Impaler spear - that bonus damage is not doubled with a critical hit.
Backstab attacks can also score critical hits, in which case the total backstab damage will be doubled.
When a creature is protected from critical hits, they are protected from the doubled damage, not from the hit itself; normal damage will still be done. Most helmets offer protection from critical hits.
Certain conditions can improve the chances of getting a critical hit:
- Being proficient (1 point) or better in either the single-weapon or two-handed weapon styles will allow critical hits on a roll of either 19 or 20.
- The Critical Strike and Smite HLAs allow all attacks made within a round to count as critical hits.
- The following gear offers a critical hit bonus:
- The axe Rhyte's Last Arrow
- The amulet Archer's Eyes
- The two-handed swords Dragon Blade (when enraged) and Sword of Ruin
- Herdrin's Short Sword
- The headgear Headband of Focus (unarmed attacks)
Feedback
- The combat log will provide feedback when a critical hit occurs (e.g., Minsc: Critical Hit)
- A Party member will remark when they score a critical hit (e.g., Minsc: Ah hay!)
- If the target of a critical hit is protected from critical hits, such as if they wear a helmet, the combat log will report, "Critical Hit Averted"