Specimens & Bosses

Monster Health and Damage Calculation

Each zombie has its own health parameters, resistances, and parameters for calculating "HP" with a particular number of players on the server. Each weapon or weapon type has its own damage parameters. Each perk level has its own parameters and bonuses to specific weapons and damage dealt by them. All this is taken into account when calculating the answer to the question: "How many shots will it take to kill a mob?"

Sharpshooter perk art Sharpshooter, the precision and headshot perk.

Calculation Example: Sharpshooter Level 11 - M99 - FleshPound

Sharpshooter Level 11 Parameters

Sharpshooter level 11 has a bonus to headshot damage +160% or ×2.6

M99 Parameters

M99 (standard) has these damage parameters:

  • Damage = 675.000000 - total damage
  • HeadShotDamageMult = 2.250000 - headshot damage multiplier in the weapon itself
  • HeadShotDamageMult = 1.000000 - headshot damage multiplier in DamageType

FleshPound Parameters

It has these parameters needed for calculation:

  • Health = 1500 - total "body health"
  • HeadHealth = 700 - "head health"
  • PlayerCountHealthScale = 0.25 - multiplier for calculating "body health" depending on number of players
  • PlayerNumHeadHealthScale = 0.3 - multiplier for calculating "head health" depending on number of players

Resistance to ranged weapon headshot damage:

  • If HeadShotDamageMult (DamageType) < 1.5 = 0.5
  • If HeadShotDamageMult (DamageType) > 1.5 = 0.25
  • For crossbow = 0.25 (special case)

Hell on Earth Difficulty Characteristic

All monster health is multiplied by ×1.75

Calculation Formulas

Zombie Health Calculation Formula

Body HP:

HP = (Health + PlayerCountHealthScale × Health × (N-1)) × "Hell on Earth" Multiplier

Head HP:

HeadHP(N) = (HeadHealth + PlayerNumHeadHealthScale × HeadHealth × (N-1)) × "Hell on Earth" Multiplier

where N is the number of players

Headshot Damage Calculation Formula

For weapons with projectiles (M99, crossbow):

HShDamage = Damage × HeadShotDamageMult × HeadShotDamageMult(DamageType) × level bonus

For weapons without projectiles (e.g., Hunting):

Only one HeadShotDamageMult is used (from weapon or DamageType)

Calculation Example

Calculating FleshPound Health on "Hell on Earth" Difficulty with 12 Players

Body HP:

HP = (1500 + 0.25 × 1500 × (12-1)) × 1.75
HP = (1500 + 0.25 × 1500 × 11) × 1.75
HP = (1500 + 4125) × 1.75
HP = 5625 × 1.75
HP = 9844

Head HP:

HeadHP = (700 + 0.3 × 700 × (12-1)) × 1.75
HeadHP = (700 + 0.3 × 700 × 11) × 1.75
HeadHP = (700 + 2310) × 1.75
HeadHP = 3010 × 1.75
HeadHP = 5267

Calculating Damage Dealt by Sharpshooter Level 11 with M99

Base headshot damage:

HShDamage = 675 × 2.25 × 1 × 2.6
HShDamage = 3948

With FleshPound resistance (0.5):

Final damage = 3948 × 0.5 = 1974

Final Result

Based on our calculations, a standard M99 in the hands of a sharpshooter level 11 with 12 players will kill FleshPound in the head with 3 shots:

  • Damage per shot: 1974
  • FleshPound head HP: 5267
  • Number of shots: 5267 ÷ 1974 ≈ 2.67 → 3 shots

Estimating DPS with perk bonuses

F4TAL1ST's method from the "Mutant and weapon stats" threads on the killingfloor.ru forum (2010-2011). The values are from the patches of that time. The author's spreadsheets (damage, DPS, zed health and attacks, speeds, penetration, FP and Scrake weaknesses, burn damage) were hosted on file-sharing sites and were not archived.

DPS here means damage per second with no misses. It is only accurate for the crossbow, grenade launchers, flamethrower and melee weapons.

Perk-boosted DPS: DPS x (1 + perk damage bonus). A flamethrower with a base DPS of 171 for a level 5 Firebug (+50% damage): 171 x 1.5 = 256.5.

The Berserker's perk also speeds up attacks, so its DPS is calculated differently:

Damage = average damage x (1 + damage bonus)
Interval = attack interval x (1 - attack speed bonus)
DPS = Damage / Interval

Katana for a level 4 Berserker (+60% damage, +15% attack speed): average damage 175, interval 0.6 s. 175 x 1.6 = 280, 0.6 x 0.85 = 0.51, 280 / 0.51 = 549.

Values of that time: average damage is katana 175, chainsaw 230, axe 150, machete 57.5, knife 45.1; attack interval is 0.6, 0.8, 1.2, 0.71 and 1.1 s.

Important Notes

  1. Resistances: Resistance to ranged weapon damage depends on HeadShotDamageMult in DamageType. For crossbow, a special resistance of 0.25 is used.

  2. Weapon Types: For weapons with projectiles (M99, crossbow), a formula with two HeadShotDamageMult is used. For other weapons (e.g., Hunting), only one HeadShotDamageMult is used.

  3. Difficulty: The "Hell on Earth" multiplier (1.75) applies to all monster health.

  4. Number of Players: The more players on the server, the more health monsters have. This is taken into account through PlayerCountHealthScale and PlayerNumHeadHealthScale.