STO Ground Damage Calculation

Hi everyone!

For most of us it’s a cryptic mystery how the damage of our ground weapons is actually calculated. But not any more! Our dear friends Tirius@lordcruncher and @soludor (check out their NTTE records) give some insight on this matter and share their vast knowledge with us.


The general formula for ranged ground weapons is:

Total Damage = (CombatSpec + Mkmod + 0.75 * (DamageInc + 0.25 * WpnProf) + 0.02 * WpnMods) * (1 + BonusDamage) * FinalDamage

This formula could also be posed in a shorter way, similar to the terminology used in space of “Base, Bonus and Final Damage”:

Total Damage = BaseDamage * (1+BonusDamage) * FinalDamage

The BaseDamage term is slightly different for melee weapons. The full formula for melee weapons is as follows:

Total Damage = (1 + Mkmod + DamageInc + 0.5 * (CombatSpec + WpnProf) + 0.02 * WpnMods) * (1 + BonusDamage) * FinalDamage

The different attack abilities on your weapons (primary, secondary, tertiary) determine the number of affected targets and the final damage buff.


Types of Damage Increases

BaseDamage is essentially the sum of following enhancements:

  • CombatSpec: The value of Combat Specialist is equal to 0.0333 * your level for levels under 30. After that it is 1.
  • WpnProf: The Weapon Proficiency skill is multiplied by 0.25*0.75 (=0.1875) for ranged weapons and 0.5 for melee weapons. This value is then added to the BaseDamage.
  • MkMod: A Mark XIV ranged weapon has a MkMod of approximately 1.287 (1.8 for melee weapons). See section “Weapon Mark Modifier” below for more information.
  • DamageInc: See a list of DamageInc increases below. All Damage increases are summed up first and then multiplied by 0.75 if it is a ranged weapon before being added to the BaseDamge. Damage increases are not multiplied by 0.75 on melee weapons.
  • WpnMods: Generic weapon modifier like CrtH, CrtD, KB* and Dot* provide an additional 0.02 BaseDamage increase per modifier, while Dmg, Run and Sonic do not.

BonusDamage is the sum of all Bonus Damage buffs and FinalDamage is the product of all final buffs.


  • [Ene] Mod on armors (5% Energy Damage)
  • Target Optics (50% All Damage at III)
  • Iconian Resistance Elite 3 Set Bonus (33% All Damage)
  • Counter-Command Elite 2 Set Bonus (10% Phaser and Disruptor Damage)

Bonus Damage increases:

  • Critical Severity (base value: 50%)
  • Exploit Damage (base value: 200%)
  • other Bonus Damage enhancements

Final Damage increases:

  • Dmg-Mods: Each [Dmg]-Mod provides a 1.03 final multiplier. Any [*/Dm] epic mod also provides a 1.03 final multiplier.
  • Epic-Mod: Besides the two modifiers inside an epic modifier, all epic weapons gain a 1.03 final multiplier in addition to these two modifiers (e.g. An epic beam array with [Dmg]x4 [CrtD/Dm] has six 1.03 final multipliers on it: four from [Dmg]x4, one from being epic and another one from the “Dm” inside its epic modifier [CrtD/Dm]).
  • Weapon Type Multiplier: Each attack adds another multiplier based on the weapon attack type (primary, secondary or tertiary) that is used.
  • Ranged/Melee Multiplier: Multiplier of 20 for ranged and 18 for melee weapons.
  • Most ranged weapons have a variance of 10% which leads to a final multiplier between 0.9 and 1.1.


Weapon Mark Modifier

The Mkmod for ranged weapons for each Mark can be roughly approximated by:

\(\mathrm{Mkmod(Mark)} = \begin{cases} 0.0765 * (\mathrm{Mark} – 1)& \mathrm{Mark} < 13\\ \mathrm{Mkmod(12)}+0,145 & \mathrm{Mark} == 13\\ \mathrm{Mkmod(13)}+0,301 & \mathrm{Mark} == 14\\ \end{cases}\)

Using a Mkmod modifier of 1.2878 for Mk XIV ranged weapons leads to similar results like the actual tooltip values.

For melee weapons:

\(\mathrm{Mkmod(Mark)} = \begin{cases} 0.0815 + 0.102 * (\mathrm{Mark} – 1)& \mathrm{Mark} < 13\\ \mathrm{Mkmod(12)}+0.196 & \mathrm{Mark} == 13\\ \mathrm{Mkmod(13)}+0.4 & \mathrm{Mark} == 14\\ \end{cases}\)

The Mkmod value for a Mk XII melee weapon is 1.202 and 1.8 for a Mk XIV melee weapon.


Weapon Type Multiplier

The most common crafted weapons are listed with their final multiplier in the table below.

Weapon Attack Type Multiplier Expose/Exploit
Split Beam Rifle Primary 1.3  
  Secondary 3 Exploit
Sniper Rifle Primary 1.85  
  Secondary 5 Exploit
Full Auto Rifle Primary 1.25  
  Secondary 0.8 Expose
High Density Primary 1.3  
  Secondary 3.5 Exploit
Compression Pistol Primary 1.4  
  Secondary 4.2 Exploit
Dual Pistols Primary 1.3  
  Secondary 1 Expose
Stun Pistol Primary 1.25  
  Secondary 0.5 Expose
Wide Beam Pistol Primary 1.25  
  Secondary 4 Expose
Minigun Primary 1.3  
  Secondary 0.8 Expose
Blast Primary 1.3  
  Secondary 3.5 Expose
Pulsewave Primary 4 – 1.5  
  Secondary 6.67 – 2.5 Expose

Basic attacks of melee weapons:

Weapon Attack Type Multiplier Expose/Exploit
Sword Slash Primary 0.8 Expose
  Secondary 1.2 Exploit
Bat’leth Slash Primary 1.25 Expose
  Secondary 1.25 Expose

A few special weapons:

Weapon Attack Type Multiplier Expose/Exploit
Boolean Heavy Assault Cannon Primary 8.8  
  Secondary 4.2 Exploit
Advanced Herald Antiproton Beam Projector Primary 1.85  Expose
  1st Chain (Primary) 0.396  
  2nd Chain (Primary) 0.198  
  Secondary 3.9  


Expose-Exploit Mechanic

Some abilities have a chance to expose a target and have a base chance of 10%. Once a target is exposed, an exploit ability can be used on this target to consume its exposed state. An exploit attack deals 200% more bonus damage. After a successful exploit attack, the target is no longer exposed. Expose chance, exploit damage and expose duration can be increased eg. by traits. 


Kit Modules

Some stats of kit modules scale with Skills, Mark and Quality. The following list contains examples of some kit modules and how their stats are calculated.

  • Ambush
    • (7+r) * 5 * (1+mk/10) * (1+Kperf/2) Bonus All Damge
  • Trajectory Bending
    • 20 * (1+mk/10) * (1+KPerf/2) Critical Severity
  • Rally Cry
    • min(r,3) + 4 Critical Chance
    • (min(r,3) + 4) * 10 Critical Severity

Where r is the rarity (Common = 0, Uncommon = 1, …) and mk ∊ [1,14] the kit’s mark. It appears that damage increasing stats are influenced by KPerf and mk in the same way for some kit modules.


9 comments to STO Ground Damage Calculation

  • Weaselone  says:

    Nice. Thanks for doing all the hard work on this.

  • whicky1978  says:

    Thank you for posting this. Trajectory Bending might be the cheapest of these three kit modules. All three of those cat modules are obtainable on a budget.

    • Tirius  says:

      Please note that these modules were selected for the sole purpose of demonstrating how skills, mark and quality affect their stats. Understanding these examples might help you to understand the scaling of other kit modules.
      Ambush, Trajectory Bending and Rally Cry are great modules, but we also have ground build recommendations in our guide section.

  • Casualsto  says:

    So now ground DMG mod is also cat2? The 1.03x multiplier (final) means cat2. So DMG becomes viable also on ground builds?

    • felisean  says:

      no, dmg is a final modifier. its the multiplier you said.

      bonus damage is called cat 2 from some people but since +% bonus dmg is the name ingame i still prefere that one.

  • Casualsto  says:

    So it adds in the final calculations, but before any buffs are taken into account? I know that cat2/+% bonus are calculations made after all buffs have been applied. DMG is calculated before those?

    • felisean  says:

      its all in the post, let me quote:
      Total Damage = BaseDamage * (1+BonusDamage) * FinalDamage

  • Plan Tain  says:

    What is the Mark Mod for mark 15 weapons?

    • Plan Tain  says:

      The Weapon Mark Modifier section is confusing me. The formula indicated in the first part seems to not match the conclusion in the final sentence:

      “Using a Mkmod modifier of 1.2878 for Mk XIV ranged weapons leads to similar results like the actual tooltip values.”

      But no matter how I try to calculate the value using the formula, I come up with a different number (1.2955 or 1.219).

      Do we know the source of this information, and how best to recreate it (the end goal being to find the MK15 Weapon Mark Modifier)?

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