Weapon damage

Version 0.14: This article may not be up to date for the latest stable release of Crawl.

Weapon damage is your base weapon damage, multiplied by weapon skill and fighting skill, and your strength bonus depending on the strength weighting of the weapon type. Slaying bonuses and weapon enchantment are added afterwards. Actual damage is randomly rolled, 1dWeaponDamage.

Damage formula

Damage = {[1d(Base damage * Stat modifier)-0.66] * Weapon skill modifier * Fighting modifier
         + Misc modifiers + Slaying bonuses}
         * Final multipliers  + Stabbing bonus - AC damage reduction

• Base damage:
  • Unarmed combat: 3 + UC (can be changed by some spells, see Unarmed combat)
  • Using a weapon: Base damage of the weapon
• Stat modifier:
  • Stat = STR + (dex_weight/10) * (DEX - STR)/2 (a number between STR and (STR+DEX)/2)
  • If Stat > 11: Multiply by 1 + 1d(Stat - 11)*2/39 (average bonus: +2.6% for every point above 11)
  • If Stat < 9: Multiply by 1 - 1d(9 - Stat)*3/39 (average bonus: -3.8% for every point below 9)
• Weapon skill modifier: Multiply by 1 + (1dSkill)/25 (not applied to unarmed combat; average bonus: +2% for every skill level)
• Fighting modifier: Multiply by 1 + (1dFighting)/30 (average bonus: +1.67% for every skill level in fighting)
• Misc modifiers:
  • Might or Berserk: +1d10
  • If you are starving: -1d5 + 1 (bloodless vampires don't suffer this penalty)
• Slaying bonuses:
  • Effective enchantment = Weapon enchantment + Slaying bonus
  • If Eff. enchantment > 0: + 1d(1 + Eff. enchantment) - 1
  • If Eff. enchantment < 0: - 1d(1 - Eff. enchantment) + 1
• Final multipliers:
  • If it is an additional cleaving attack: Multiply by 0.75
  • Statue Form: Multiply by 1.5
  • If the player has the Weak status effect: Multiply by 0.75
• Stabbing bonus: See stabbing.
• AC damage reduction: See AC.

Some considerations:

• The main contributions to weapon damage are: base damage, weapon skill (+54% at level 27) and fighting skill (+45% at level 27).
• As you can see, at very low skill levels, the value of base damage and enchantment is approximately the same, but for skilled characters base damage is much more important than enchantment.
• Weapon brands that use multiplicative bonuses, calculate the additional amount of damage as a percentage of the damage described in this page (including AC damage reduction). This additional amount of damage ignores AC, but it can be affected by resistances or vulnerabilities.

Example

Disregarding weapon speed, which is better, a +5 War axe or a mundane +0 battleaxe?

Assume our character has both a strength and dexterity of 15, an Axes skill of 10, and a Fighting skill of 10.

In our damage formula (see above), we will ignore AC reduction, stabbing bonus, potions of might, berserk, and other unusual factors. This reduces our formula to:

Damage = {[1d(Base damage * Stat modifier)-0.66] * Weapon skill modifier * Fighting modifier + Slaying bonuses}
         

For both axes the Stat modifier will be 1 + (1d4*(2/39)); the weapon skill modifier will be 1 + ((1d10)/25); and the fighting modifier will be 1 + ((1d10)/30). The base damage for a war axe is 11; the base damage for a battleaxe is 15. The slaying bonus for the +5 war axe is (1d6)-1 and for the battle axe is 0.

When we factor all of these in, we get these worst case scenarios (all rolls = 1) and best case scenarios (all rolls = maximum) (and values rounded to nearest whole integer):

+5 War Axe, worst case:

{[1d(11 * (1+(1*(2/39))-0.66] * 1+1/25 * 1+1/30 + (1-1)} = {[1d11] * 1.04 * 1.033 + 0} = 1 to 12

+5 War Axe, best case:

{[1d(11 * (1+(4*(2/39))-0.66] * 1+10/25 * 1+10/30 + (6-1)} = {[1d13] * 1.4 * 1.33 + 5} = 7 to 29

+0 Battleaxe, worst case:

{[1d(15 * (1+(1*(2/39))-0.66] * 1+1/25 * 1+1/30 + 0} = {[1d15] * 1.04 * 1.033 + 0} = 1 to 16

+0 Battleaxe, best case:

{[1d(15 * (1+(4*(2/39))-0.66] * 1+10/25 * 1+10/30 + 0)} = {[1d17] * 1.4 * 1.33 + 0} = 2 to 32

The +5 war axe can't match the maximum possible damage of the regular +0 battleaxe, but the +5 war axe is more likely to have reliable lower and mid-range damage. This is not likely to be helpful against high-AC creatures, since you need to overcome AC to do any damage. The +0 war axe may be slightly more useful against high-AC targets if it hits the 30+ damage rolls; against low AC targets the war axe may be more consistently damaging.

This example shows how large a difference the base damage of the weapon, plus the fighting and weapon skills, make on total damage. At very high levels (weapon & fighting = 20), the maximum damage output is a multiple of 3 (1.8*1.66). A +5 war axe would have a maximum of 44; the +0 battleaxe a maximum of 51. If the battleaxe has a damage-multiplying brand like flaming or frost, the larger total means more of that brand's damage.

For comparison, a +20 hand axe has a maximum possible damage of 44 under the same conditions.

History

Between 0.8 and 0.13, melee weapons of speed suffered a -10% penalty to damage.

In 0.13 the effect of stats on melee was doubled.