Damage (Long War)

Terms

Base Weapon Damage (BWD): This is each weapon damage stat configurable in DefaultGameCore.ini file. The weapon ranges shown in game in barracks are computed from this stat based on the randomization process, with an algorithm designed by Amineri for long war.

Modified Weapon Damage (MWD): This is the median damage after most modifiers, on which the randomization process (+/- 25%) is applied. Increases to MWD, such as Ranger and Vital Point Targeting, increase the overall damage range.

Weapon Damage Calculation

Steps for calculating damage:

1. Roll for hit chance and crit chance
2. Apply penalty to BWD due to skills
3. Compute Modified Weapon Damage (MWD) by adding all bonus damage from equipped items and relevant perks
   • Add bonus critical damage if a critical hit is rolled
4. Damage randomization: roll for damage value between roughly 75% to 125% of MWD
   • Roll between roughly 125% to 175% of MWD if a critical hit
5. Apply further randomization and range fall off for Explosives
6. Subtract target DR
7. Add any extra bonus damage from certain perks

Accuracy and Critical Chance

All sources of defense on the target are subtracted from all sources of aim on the shooter to produce a percentage hit chance equal to the net result out of 100. The breakdown can be viewed by using F1 while targeting an enemy, which displays the hit chance of a particular attack.

Critical chance is likewise computed by adding up all sources of critical chance and subtracting any critical chance penalties. The Resilience perk reduces critical chance to zero. Reaction fire can't critically hit without the Opportunist perk or if the target is wearing the Chameleon Suit.

Overwatch fire receives unique multiplicative penalties. These are applied after normal hit chance is calculated.

Additive Sources of Aim

Persistent Sources:

• Aim of Shooter: ~65 (for average rookies)
• All laser-tech Weapons: +6
• All Carbines: +6
• Superheavy Plasma [SHIV Weapon]: +8
• Laser Sight [Small Item]: +4
• SCOPE [Small Item]: +8
• Neural Gunlink [Small Item]: +12
• Illuminator Gunsight [Small Item]: +12
• Alloy Bipod [Small Item]: +6
• Smart-shell Pod [SHIV Equipment]: +4
• Holo-targeter [MEC Equipment]: +4
• Battle Computer [MEC Equipment]: +8
• Drum Mags [Small Item]: -4
• Rail Pistols [Foundry project]: +8 for sidearms only
• Band of Warriors [Officer Perk]: +2 per continent bonus XCOM has earned
• So Others May Live [Officer Perk]: +1 per mission survived with zero casualties (up to +8)

Conditional Sources:

• Height Advantage (for being at a higher elevation than the target): +20
• Close Range Advantage (for being close to the target): +0 to 30 (doubled for shotguns)
• Close Range Penalty (for being too close with a long-range weapon): -0 to 30
• Long Range Penalty (for being too far with a close-range weapon): -0 to 30
• Flush [Weapon Skill]: +30 for the Flush shot
• Disabling Shot [Weapon Skill]: -10 for the Disabling Shot
• Rapid Fire [Weapon Skill]: -15 for both attacks
• Damn Good Ground [Perk]: +10 against enemies in lower elevation
• Deadeye [Perk]: +15 against flying enemies
• Executioner [Perk]: +10 against targets at 50% or less health
• Lone Wolf [Perk]: +10 when not within 7 tiles of a friendly unit
• Platform Stability: +10 before taking any costly (blue) actions
• Sharpshooter [Perk]: +10 against targets in full cover
• Snapshot [Perk]: -10 after taking a costly action
• Depth Perception [Gene Mod]: +5 against enemies in lower elevation
• Hyper-Reactive Pupils [Gene Mod]: +10 on any shot after a miss
• Adrenaline Surge (as from e.g. Combat Stims) [Perk]: +10 until the end of the mission after taking damage

Temporary Sources:

• Holo-Targeting [Perk]: +10 against target until start of next turn
• Suppressed (as from Suppression [Effect]: -30 for one turn or until the suppression ends
• Disoriented (as from e.g. Flashbang) [Effect] : -50 for 2 turns
• Acid-covered (as from e.g. Chem Grenade) [Effect]: -20 for 2-4 turns
• Mindfray [Psionic Skill]: -25 for 3 turns

Additive Sources of Defense

Persistent Sources:

• Defense of Target: ~0 (for average rookies)
• Plasma Carbine (Weapon): +6
• Chameleon Suit [Small Item]: +4
• Reinforced Armor [Small Item]: -6
• Battle Computer [MEC Equipment]: +8
• Esprit de Corps [Officer Perk]: +5

Conditional Sources:

• Half Cover: +30 (+60 hunkered)
• Full Cover: +45 (+90 hunkered)
• Flight Mode [Granted by Antigrav armors]: +30
• Tactical Sense [Perk]: +5 per enemy in view, up to +20
• Automated Threat Assessment [Perk]: +15 while on overwatch, before the first overwatch shot
• Damn Good Ground [Perk]: +10 against enemies in lower elevation
• Semper Vigilans [Officer Perk]: +5 while in cover
• Distortion Field [Psionic Ability]: +10 to allies in cover within 4 tiles

Temporary Sources:

• Smoke Grenade: +20 (smoke lasts for 2 full turns)
• Dense Smoke: +40, instead of +20 (smoke lasts for 2 full turns)
• Telekinetic Field [Psionic Ability]: +40 for 1 full turn

Sources of Critical Chance

Persistent Sources:

• All Pulse-tech: +8
• All Carbines: +4
• All Assault Rifles: +8
• All Battle Rifles: +8
• All Shotguns: +16
• All Marksman Rifles: +12
• All Sniper Rifles: +20
• Laser Sight [Small Item]: +4
• Targeting Module [Small item]: +8
• SCOPE [Small Item]: +8
• Neural Gunlink [Small Item]: +12
• Illuminator Gunsight [Small Item]: +12
• Alloy Bipod [Small Item]: +6
• Reaper Pack: +16 for Beam/Pulse weapons
• Sharpshooter [Perk]: +10

Conditional Sources:

• Flanked or Exposed Target: +50
• Hardened [Perk] Target: -60 (-30 when shot by the Gauss Long Rifle)
• Precision Shot [Skill]: +30 for the Precision Shot attack
• Adrenaline Surge (as from e.g. Combat Stims) [Perk]: +10 after taking damage
• Aggression [Perk]: +10 per enemy in sight, up to +30%
• Executioner [Perk]: +10 against targets at 50% or less health
• Lone Wolf [Perk]: +10 when not within 7 tiles of a friendly unit
• Platform Stability [Perk]: +10 before taking any costly (blue) actions
• Squadsight [Perk]: -20 to targets past visual range
• Depth Perception [Gene Mod]: +5 against enemies in lower elevation

Temporary Sources:

• Combat Drugs: +20 (smoke lasts for 2 turns)
• In The Zone [Perk]: -10 for each successive In The Zone kill during your turn

Overwatch Penalties

Overwatch fire (not including Suppression) has multiplicative penalties applied to it after normal hit is calculated. All penalties stack multiplicatively with each other.

• Base Reaction Fire penalty: x0.7, or x0.5 if the target is dashing (removed if the shooter has the Opportunist perk)
• Lightning Reflexes: x0.1 for the first shot, and x0.3 for each subsequent shot.
• Chameleon Suit: x0.5

Damage Penalties

Penalties to base damage from special skills are applied here. Because the damage is rounded down to the nearest integer, increasing weapon tech levels to an odd BWD will not increase the damage of special skills. Note that sources of extra damage are not reduced by these special skills, as they apply only to base damage.

• Flush: Damage is reduced to 50% of BWD.
• Shredder Rockets: Damage is reduced to 60% of BWD.
• Disabling Shot: Damage is set to 1.

Computing Modified Weapon Damage (MWD)

MWD is the sum of BWD and all the flat bonuses to weapon damage from equipped items and relevant perks. If a critical hit was previously rolled, all sources of critical hit damage are added as well, and the average damage is increased by ~50% in the randomization step.

Note that Mayhem Suppression always has an MWD of exactly 2 regardless of other additive modifiers, and no randomization is applied to it.

Sources of MWD

• Ranger [Perk]: +1 to all Primary Weapons and Secondary Weapons
• Vital-Point Targeting [Perk]: +2 to Primary Weapons & the Kinetic Strike Module, and +1 to Sidearms, vs. EXALT, Zombies, Outsiders and autopsied aliens
• Mayhem [Perk]: +4 for Sniper Rifles and Marksman Rifles (Does not apply to Disabling Shot), +2 for all Explosives, +2 for SAWs and LMGs, +1 for Flush attacks.
• In the Zone [Perk]: -1 for each successive In The Zone kill during your turn
• Sapper [Perk]: +1 for HE & AP, and +2 for Alien Grenades
• Alloy-Jacketed Rounds [Small Item]: +1 to Ballistic and Gauss weapons
• Enhanced Beam Optics [Small item]: +1 to Laser and Pulse weapons
• Plasma Stellerator [Small Item]: +1 to Plasma weapons
• Reflex Pistols [Foundry Project]: +1 for all Sidearms
• Enhanced Plasma [Foundry Project]: +1 for all Plasma weapons
• Alien Grenades [Foundry Project]: +2 for AP Grenades
• Heavy Plasma Rifle [Weapon]: +1 when steadied
• Plasma Dragon [Weapon]: +1 to flying targets
• Particle Cannon [MEC Weapon]: +1 to robotic targets

MWD Critical Hit Bonuses

Note: the game adds all sources of critical damage before the ~50% critical hit bonus in the randomization step, but all in-game descriptions of bonus critical damage include the ~50% bonus, so in-game descriptions will be ~50% higher than mentioned here, but the net effect is the same in most cases.

• Targeting Module [Small Item]: +1
• Precision Shot [Skill]: +2 for Ballistic, Laser, and Gauss; +3 for Pulse; +4 for Plasma (for Sniper Rifles only)
• Bring Em On [Perk]: +1 damage for 1-2 visible enemies; +2 damage for 3-4 visible enemies; +3 damage for 5-6 visible enemies; +4 damage for 7 or more visible enemies
• Killer Instinct [Perk]: +33.4% of BWD, rounded up; ranges from +2 to +4 depending on weapon and tech level, see the chart, below
• Plasma Rifle [Weappn]: +1 to Biological targets
• Reflex Cannon [Weapon]: +1 on targets within 4 tiles
• Reflex Rifle [Weapon]: +1 to flanked or exposed targets
• Plasma Sniper Rifle [Weapon]: +1 to targets beyond 35 range (~23 tiles)

Damage Randomization

The purpose of the randomization is to pick a integer value between roughly MWD*0.75 and MWD*1.25 with an average of MWD*1.0. For critical hits, the same length interval is used, except shifted to an average of ~MWD*1.5, though critical hits will always at least as much damage as the highest possible roll for a regular hit, and this requirement sometimes increases the average past 1.5*MWD. Damage Roulette changes the range from 0.5*MWD to 1.5*MWD, with the average damage of critical hits increased to MWD*2.0; again, with the same damage range.

The randomization works in integer values only. A die of size 2*MWD+2 is rolled, where each integer point of final damage is assigned up to four possible results on that die (except for the highest and lowest values, which may be assigned less). The weighted average of all possible results equals MWD. For a better understanding, reference the charts, below.

MWD Randomization Table: Regular Hit

Y axis has MWD values. Row values are possible randomisation results for that particular MWD based on the 2*MWD+2 system. The rightmost column has weapon's damage range (min,max) for that MWD. The probability to roll a particular value given a particular MWD is (number of times value appears in the row) / (total number of values in the row).

MWD Randomization Table: Critical Hit

Y axis has MWD values. Row values are possible randomization results for that particular MWD based on the 2*MWD+2 system. The rightmost column has weapon's damage range (min,max) for that MWD. The probability to roll a particular value given a particular MWD is (number of times value appears in the row) / (total number of values in the row). Note that the average damage is shifted approximately 50% (or more) higher, and the lowest damage roll is always equal to or higher than the largest damage roll in the corresponding row of the regular hit table.

Extra Explosive RNG

Each unit has the damage reduced based on distance from the center. Damage falls as the square of the radius, down to 25% at the edge.

Explosives also have extra RNG associated with them. Each target hit is equally likely to randomly roll +1, 0, or -1 to damage, reflecting a higher damage range than regular weapons.

Damage Reduction

Long War adds a new mechanic called Damage Reduction. When a unit takes damage, the amount is reduced by the damage reduction value. The amount blocked by damage reduction can be seen in game as a blue shield icon below the normal red damage indication text after a shot.

If the damage reduction a unit has is not a whole number, the damage is reduced by one of the two nearest whole numbers, with probability based on the fraction. For example, a unit with 1.66 damage reduction has a 66% chance of the damage being reduced by 2 and a 34% chance of the damage being reduced by 1.

The steps to calculating DR are as follows:

1. Flat Inherent DR is applied
2. Acid negates the higher of 50% or 3 points of the above DR.
3. Percentage DR is applied (multiplicatively) to the remaining damage
4. Flat Cover DR is applied, if the target is in cover and not flanked, and the weapon is not an AP Grenade or Shredder Rocket
5. Other effects that negate DR (except acid) are applied
6. If there is any net DR from the above steps, it is multiplied by 1.5 if damage source is a shotgun without breaching ammo

Sources of DR

Flat Inherent DR

From Armor:

• Alien Inherent DR: ranges from 0.0 to 9.0 depending on alien type and research level.
• Titan Armor: 0.5
• Archangel Armor: 0.3
• MEC-1 Paladin: 1.0
• MEC-2 Defender: 1.5
• MEC-3 Valiant: 1.0
• MEC-4 Dauntless: 2.0
• MEC-5 Devastator: 2.5
• MEC-6 Vanguard: 1.0
• MEC-7 Vindicator: 1.5
• SHIV: 1.5
• Alloy SHIV: 2.5
• Hover SHIV: 2.0

Other Sources:

• Reinforced Armor [Small Item]: +1.0
• Psi Screen [Small Item]: +1.0
• Iron Skin [Gene Mod]: +1.0
• Damage Control [Perk]: +1.5 for 2 turns after taking damage
• Mind Merge [Psionic Ability]: +(<Will of caster> / 50)
• One For All [MEC Ability]: +1.0

Note: each Ethereal still alive in the final Temple Ship room adds 15 bonus DR to the Uber Ethereal.

Percentage DR

Damage in excess of inherent DR has the following stacking multipliers applied to it. For instance, a Mectoid with Psi Shield and Shock-Absorbent Armor who is attacked from close range reduces the resulting damage to to 0.5*0.667 = 0.3335 of it's normal value, so a shot that rolled 21 damage deals 21*0.3335 = 7 damage, with 14 blocked by DR.

• Psi Shield (Mechtoid ability): x0.5
• Combat Stims: x0.6 if user is in cover and not flanked
• Chitin Plating/Chryssalids: x0.6 versus melee damage
• Shock-Absorbent Armor: x0.667 if source is within 4 tiles
• Absorption Fields: x0.6 to any of the damage beyond 2 points (e.g. 12 → 2 + 10*0.6 = 8)

Flat Cover DR

Applies only if the target is in cover and not flanked, and the weapon is not an AP Grenade or Shredder Rocket.

• Low Cover: +0.667
• Full Cover: +1.0
• Hunker Down: a further +0.667 or +1.0 depending on cover
• Fortiores Una: a further +0.667 or +1.0 depending on cover
• Will to Survive: 1.5

Flat DR Reduction

DR reduction cannot exceed the targets DR; that is, any DR reduction beyond that amount is ignored. Note that acid is in it's own separate category; reference the steps to calculating DR above.

• Combined Arms [Perk]: -1.0
• Armor-Piercing Ammo [Small Item]: -2.0
• Gauss Weapons: -0.34
• Quenchguns [Foundry Project]: -0.67, instead of -0.34 for normal Gauss weapons

Bonus Damage

Some sources of bonus damage are applied after all other steps, including MWD, randomization, and DR.

• Shredder Ammo: If the target is shredded, the remaining damage after DR (if any) is multiplied by 1.4 rounded down, with a minimum increase of 1. Shredding can be completely negated by DR, but if the resulting damage after DR is non-zero, Shredding will always add at least 1 extra point of damage. The shredder bonus does not apply to any extra damage from the other bonus sources in this list.
• HEAT Ammo & HEAT Warheads: If the target is robotic, HEAT adds a bonus of 0.5*BWD rounded down. Note that it adds Base Weapon Damage. Even if the attack was reduced to zero damage through DR, HEAT will still inflict it's full damage. Reference the charts below for a detailed breakdown on the bonus damage for each weapon type.
• Flak Ammo: If the target is flying, Flak Ammo adds a bonus of 0.2*BWD rounded up, or 2, whichever is higher. This is functionally similar to HEAT ammo. Most weapons gain a bonus of 2 from Flak Ammo; weapons with base damage of between 11 and 15 gain 3.

Multiplicative Damage Perk Charts

HEAT Ammo

HEAT Ammo bonus damage, by weapon.

	SAW	LMG	SHIV Weapon	MEC Weapon	Sniper Rifle
Ballistic	+2	+3	+3	+3	-
Laser	+3	+3	+4	+4	-
Gauss	+3	+4	+4	+4	+3
Pulse	+4	+4	+5	+5	-
Plasma	+4	+5	+5	+5	-

Heat Warheads

HEAT Warheads bonus damage for grenades.

	Damage
HE	+2
AP	+2
Alien Grenade	+2

HEAT Warheads bonus damage for rockets.

	Damage
Rocket Launcher	+3
Recoilless Rifle	+4
Blaster Launcher	+6

Killer Instinct

Bonus added to MWD on critical hits, per weapon.

	Carbines	Assault Rifles	Battle Rifles	SMGs	Shotguns	Pistols	Machine Pistols
Ballistic	+2	+2	+2	+2	+3	+1	+2
Laser	+2	+2	+3	+2	+3	+2	+2
Gauss	+2	+3	+3	+2	+3	-	+2
Pulse	+3	+3	+3	+3	+4	-	+3
Plasma	+3	+3	+4	+3	+4	+2	+3

Note that critical hits are scaled up by ~50% in the damage randomization step, so all values here will be increased by 50% for the purposes of their effect on final damage.