Combat Calculations

This page details the mathematical formulas behind combat. It combines all the mechanics for Accuracy and Damage described elsewhere. Accuracy and damage can be affected by effects on the weapons, on the attacker, and on the opponent.

It is not necessary to know or use these formulas. Accumulating recoil, accuracy, and estimated damage are displayed when moving and highlighting enemies. Factors in accuracy and damage are listed in the upper right corner when preparing an attack. It is not possible to predict random rolls or to see the results of the random roll afterward. These formulas are provided only to assist those who want to see all the factors involved in Recoil, Accuracy, Damage, and Critical Hits in one place in mathematical form.

Recoil

Recoil reduces accuracy. It accumulates from movement and attacks made earlier in the Turn, which makes late-round attacks less accurate than early-round ones. Recoil resets to 0 at the end of the Turn.

Movement Recoil

All characters gain 2% Recoil per AP spent moving.

• CurrentRecoil: Current recoil before movement
• MoveAP: Number of Action Points and/or Movement Points used in the movement

NewRecoil = CurrentRecoil + (2 * MoveAP)

Note that some Talents allow movement without accumulating Recoil.

Attack Recoil

All attacks generate Recoil, whether using firearms or melee Weapons. Each weapon has a listed Recoil value for its attacks. After an attack, 75%-100% of that Recoil value is added to the character for the rest of that turn. Some characters may have Recoil reduction through Talents, Traits, or Cyberware, which reduces the Recoil generated by attacks.

• CurrentRecoil: Current recoil before movement
• WeaponRecoil: Amount of recoil normally generated by Weapon plus mods
• RecoilReduction: % reduction in recoil from Cyberware, Traits, Attributes, Talents, and Items
• RecoilRoll: random roll modifying how much recoil is generated

RecoilRoll = 75% to 100% [randomly generated with each attack]

Both Recoil Reduction and the Recoil Roll reduce the amount of recoil generated by an attack. At this time, it is not clear whether Recoil Reduction and Recoil Roll are combined before multiplying the Weapon Recoil, or whether each is applied separately. One of the two equations is correct, but it is not clear which one:

NewRecoil = CurrentRecoil + (WeaponRecoil * (RecoilRoll - Recoil Reduction))

NewRecoil = CurrentRecoil + (WeaponRecoil * (100% - Recoil Reduction) * RecoilRoll)

Accuracy

All accuracy modifiers are additive. A 10% increase in weapon accuracy will directly offset a 10% increase in Evasion or 10% Recoil. Similarly, reductions in chance to hit through Recoil, Cover bonuses, range penalties, and/or evasion are all equivalent.

To get your attack's chance to hit, simply add up all relevant factors. These will also be summed for you on the attack preview and the attack's chance to hit will also be displayed in the text recap after the attack.

• BaseAcc: Weapon accuracy including Mods, listed in Weapon description under Accuracy
• BonusAcc: Total bonuses to accuracy for Cyberware, Talent Nodes, Traits, Talents, and Items including for specific Weapon types and targets; can be negative
• Surprise: Bonus to accuracy for if attack is made with Surprise
• Highground: Bonus if target is on a lower level; this can be 10% for a 2m advantage or 15% for a 4m+ advantage
• Evasion: Penalty for Evasion bonus on target from Cyberware, Talent Nodes, Traits, Talents, and Items; can be negative
• CoverBonus: Bonuses to Cover on target from Cyberware, Talent Nodes, Traits, Talents, and Items; can be negative
• Obstruction: Bonus to Target if obstruction in line-of-sight; negated by Piercing weapons
• Recoil: Penalty for previously accumulated Recoil; canceled by Focused Fire--successive shots at the same target
• IgnoreRecoil: Attribute which allows ignoring some recoil, from Cyberware, Traits, Talents, and Items
• RangePenalty: Penalty for target range outside Optimal Range

Surprise = +25 [if attacker is Hidden or Hunted, or if target is Unaware or Suspicious] or 0

Highground = +15 [4m or more height advantage] or +10 [2m to less than 4m advantage] or 0 [less than 2m advantage]

CoverBase = +50 [if target in Hard Cover] or +25 [if target in Soft Cover] or 0

Cover = CoverBase + CoverBonus [if target in Cover and (CoverBase + CoverBonus)>0] or 0

Obstruction = +10 [if Obstruction in line-of sight and not negated by Piercing weapon] or 0

TotalRecoil = 0 [if Focused Fire in effect] or Recoil - IgnoreRecoil [if (Recoil - IgnoreRecoil)>0] or 0

• InnerOR: Inner edge of Optimal Range including Mods, listed in meters in Weapon description under Optimal Range
• OuterOR: Outer edge of Optimal Range including Mods, listed in meters in Weapon description under Optimal Range
• Range: Range to target in meters

RangePenalty = (InnerOR - Range) ^ 2 [if Range < InnerOR] or (Range - OuterOR) ^ 2 [if Range > OuterOR] or 0

TotalAcc = BaseAcc + BonusAcc + Surprise + Highground - Evasion - Cover - Obstruction - TotalRecoil - RangePenalty

TotalAcc acts as a percentage, rolled against a d100 to hit. A roll equal to or below TotalAcc will be a hit. Each bullet in a Full-Auto attack gets a separate Accuracy roll to hit.

Damage

Normal Damage

"Weapons deal 75-100% of the listed damage when they hit, which is then reduced by relevant armor (e.g. Ballistic Armor reduces Ballistic Damage). A hit will deal normal damage, and also deal additional damage if they are critical hits. Some misses become glancing hits, which deal reduced damage. Below are all the considerations that modify damage to a target.

Each bullet in a Full-Auto attack and each strike from a Cybersword's Slashslide gets separate rolls for accuracy, damage, and critical hit.

• BaseDmg: basic weapon damage including mods, either Ballistic or Kinetic, found in Weapon description under Damage
• Bonus: % total bonuses to damage for Cyberware, Talent Nodes, Traits, Talents, and Items including bonuses for specific Weapon types and targets; can be negative
• PureDmg: pure damage from Weapon, found in Weapon description under Pure Damage
• ExtraPD: % "extra pure damage" from Cyberware, Traits, Attributes, Talents, and Items
• Armor: % armor soak due to armor protection of target
• ArmorBonus: % bonus to armor on target, muliplicative with armor soak; can be negative
• BIArmor: % built-in armor of target from Cyberware, Traits, Attributes, Talents, and Items
• DmgRoll: random roll for damage

DmgRoll = 75% to 100% [rolled randomly]

NormalDmg = DmgRoll * (100% - BIArmor) * (PureDmg + (BaseDmg * (100% + Bonus) * (100% - (Armor * ArmorBonus) + ExtraPD)))

NormalDmg is the amount of damage delivered to the target for a normal hit, accounting for armor protection. A Critical Hit will give additional damage while a Glancing Hit will give less damage.

Critical Hit

A Critical Hit is a hit which deals additional damage. A miss or glancing hit cannot generate Critical Hit damage. The default probability of a Critical Hit is 0%, but many effects can add crit chance from Cyberware, Attributes, Talents, etc. Some effects add special crit chance or crit damage if the attack is made with Surprise.

Crit Chance

• BaseCrit%: Total bonuses to Crit Chance for Cyberware, Talent Nodes, Traits, Attributes, Talents, and Items
• StealthCrit%: Total bonuses to Stealth Crit Chance for Weapon, Cyberware, Talent Nodes, Traits, Talents, and Items

SteatlhCrit% = StealthCrit% [if attacker is Hidden or Hunted, or if target is Unaware or Suspicious] or 0%

Crit% = BaseCrit% + StealthCrit%

If a hit is rolled (not a Glancing Hit), an additional d10 roll is made against Crit% to see if critical damage is inflicted. A roll equal to or below Crit% will cause Crit Damage.

Crit Damage

• WeaponCritDmg: basic weapon critical damage including mods; depends on Weapon traits, default 50%
• WeaponCritBonus: % bonus to critical damage for Weapon and mods
• CritBonus: % total bonuses to critical damage for Cyberware, Talent Nodes, Traits, Talents, and Items
• StealthCritBonus: % total bonuses to stealth critical damage for Weapon, Cyberware, Talent Nodes, Traits, Talents, and Items

StealthCritBonus = StealhCritBonus [if attack with Surprise] or 0%

CritDmg = NormalDmg * (WeaponCritDmg + WeaponCritBonus + CritBonus + StealthCritBonus)

TotalDmg = NormalDmg + CritDmg

TotalDmg is the total damage of a Hit inflicted on a target, including Critical Hit Damage

Glancing Hit

For more information, see Glancing Hit Mechanics.

All weapons have a chance of Glancing Hit for attacks made at close ranges or with high accuracy:

• All attacks within 5.99 meters of the target cause a Glancing Hit if they "miss"; this categorically includes all melee attacks
• All attacks with 80%+ accuracy will cause a Glancing Hit if they "miss"
• Some firearms have the Precise Burst trait: a Burst Fire shot with 60%+ accuracy will cause a Glancing Hit if they "miss"
• The Gunslinger's Called Shot guarantees at minimum a Glancing Hit on the attack

If an attack misses (AccRoll > TotalAcc) but meets the requirements above for Glancing Hit, it will deal at least 30% damage but cannot crit or shred armor. The Glancing Hit Damage is calculated based on:

• AccRoll: Random roll on d100 against Accuracy
• TotalAcc: Total accuracy, as calculated above
• NormalDmg: Normal damage of attack, as calculated above

CalcGlanceFactor = TotalAcc*1.5 - (AccRoll / 2)

GlanceFactor = 30% [if CalcGlanceFactor < 30%] or 70% [if CalcGlanceFactor > 70%] or CalcGlanceFactor

GlanceDmg = NormalDmg * GlanceFactor

GlanceDmg is the total Glancing Hit Damage inflicted on the target.