Property:Weapon damage

Version 0.31: This article may not be up to date for the latest stable release of Crawl.

Weapon damage is your base weapon damage, multiplied by strength modifier, multiplied by weapon skill and fighting skill modifiers. Slaying bonuses and weapon enchantment are added afterwards. Actual damage components are randomly rolled in four places: 1d(Base * Strength modifier), Slaying bonus, Weapon skill modifier and Fighting modifier.

Damage formula

Damage = [uniform(Base damage * Stat modifier) * Skill modifier * Fighting modifier + Misc modifiers + uniform(Slaying bonuses)] * final multipliers + (Pre-final-multi damage * Stabbing bonus) - AC damage reduction

• While final multipliers are applied after stabbing bonus, the stabbing bonus doesn't benefit from these multipliers.

As a shorthand uniform(x) = 1d(x+1)-1 or a roll from 0 to x inclusive.

• Base damage:
  • Unarmed combat: 3 + UC skill (can be changed by current form and the claws mutation, see Unarmed combat)
  • Using a weapon: Base damage of the weapon
  • Using a thrown weapon: Base thrown missile damage + Throwing skill
    • Throwing stones: Base damage + (Throwing skill/2)
  • The heavy brand multiplies a weapon's base damage.
• Stat modifier:
  • 0.75 + (0.025 * Stat), or a 2.5% boost per stat.
  • Short Blades, Long Blades, and Ranged Weapons use dexterity. Other weapons and Unarmed Combat use strength.
  • There is a minimum modifier of 0.01 (1%), at -30 stat.
• Skill modifier:
  • 1 + uniform(Weapon skill)/25 (not applied to unarmed or throwing)
  • The other main advantage to raising a weapon/unarmed skill is decreasing your attack delay.
• Fighting modifier:
  • 1 + uniform(Fighting skill)/30
• Misc modifiers:
  • Might or Berserk: +1d10
• Slaying bonuses:
  • Weapon enchantment bonus
  • Added or subtracted from sources of slaying.
• Final multipliers:
  • If it is an additional cleaving attack: Multiply by 0.7
  • Statue Form: Multiply by 1.5
  • Shadow Form: Multiply by 0.5
  • The Weak status effect: Multiply by 0.75
  • Bonuses for Wu Jian martial attacks and Vhi's Electric Charge
  • Confusing Touch: Set to 0
• Stabbing bonus: See stabbing.
• AC damage reduction: The opponent's AC reduces damage by uniform(AC). Also see AC.

Notes

• The main contributions to weapon damage are: base damage, weapon skill (avg. +54% at level 27) and fighting skill (avg. +45% at level 27).

• At low skill values, 1 base damage roughly equals +1 slay, if ignoring slay's accuracy boost. As you gain skill, only base damage is multiplied, resulting in a greater effect. 1 base damage = 1 + (average of Stat mod * Skill mod * Fight mod) slaying, ignoring accuracy.

• When weapon damage is viewed in the 'i'nventory or with the @ command, the "Skill" bonus is Skill mod * Fighting mod, using the average of both rolls.

• Weapon brands (except heavy) are applied at the end of the formula, after AC reduction. The added damage then ignores AC.

In other words, when not accounting for rounding, the flaming and freezing brands would provide an identical benefit whether you wield an executioner's axe or a quickblade. However, because rounding down is more impactful on low base damage weapons, the brand is somewhat better on larger weapons.

Rounding

Each term in the formula is calculated in sequence and is rounded down to an integer. This rounding is worse with a weapon with low base damage. For example, take a player with Dex = 16 and Short Blades skill = 12:

• With no slaying bonuses, a +0 dagger with a base damage of 4 cannot do more than 5 damage.
• The same player wielding a +0 rapier with a base damage of 7 can do up to 11 damage.

So, the stat and skill bonuses increase the dagger's damage by 25% and the rapier's damage by 57%. The dagger would deal up to 10 damage per 10 aut, while the rapier would deal up to 18.

History

• Prior to 0.29, all weapon damage scaled with strength.
• Prior to 0.27, the strength modifier was random.
• Prior to 0.18, weapons used a mix of strength and dexterity, depending on the weapon itself.
• Prior to 0.13, stats had half the effect on melee.
• Between 0.8 and 0.13, melee weapons of speed suffered a -10% penalty to damage.