⚔️ Combat Damage Formula

The formula

Effective strength

Modifiers are additive percentages, gathered separately for the attacking and defending side (all values from the game's XML / source):

• Anti-trait bonuses — the unit's own effects vs the opponent's traits: e.g. Pikeman +100% vs Mounted (melee), Crossbowman +50% vs Melee, Ballista +100% attacking Infantry. These are the counters on the Unit Counters page.
• Promotions & general ratings — each promotion's strength/attack/defense percentages (see Promotions); a general adds rating-driven bonuses.
• Terrain & position — melee attacking across a river −50%; land↔water attacks −50%; per-unit urban/vegetation attack & defense modifiers; fighting in own family territory +10%.
• State — siege that moved this turn (unlimbered) defends at −25%; attacking from hiding +10%; some units gain bonuses vs damaged or general-led targets.

Current HP does not scale strength — a 1 HP Pikeman hits as hard as a fresh one (some attackers carry an explicit vs-damaged bonus instead).

Worked example: Hoplite attacks Horseman

The Horseman drops from 20 to 11 HP. Reversed, the Horseman attacking the Hoplite is 6 vs 9 (the anti-mounted bonus also defends in melee): 6 × 6 / 9 = 4 damage — which is why "spear beats horse" is such a hard rule.

Striking back

• Ranged attacks draw no return damage at all.
• Melee defenders deal a flat 1 counter damage per attack (not proportional) — plus 1 more against routed attackers.
• Tactician generals upgrade that to a full counterattack: 100% of the unit's own attack damage.
• Cities defend at 8 + 0.5 × citizens (CITY_STRENGTH_BASE/PER) and units capture at 50% HP.

Attack patterns (Pierce, Cleave, Splash, Circle)

Some units carry an attack pattern on top of the main hit. These are additional small attacks that resolve against adjacent / linear / surrounding tiles. They use the same damage formula but with a reduced effective strength, and the attacker doesn't take return damage from those secondary hits.

• Pierce — Spearman / Pikeman line. Hits the primary target plus the tile behind it.
• Cleave — Axeman / Maceman line. Hits the primary plus the two flanking tiles.
• Splash — Catapult / Trebuchet. Hits a 7-tile cluster.
• Circle — Macedonian Companion / certain elephants. Hits all 6 adjacent tiles.

Per the game data, the secondary-hit strength is the unit's base multiplied by a small percentage (e.g. Pierce I = +25% Pierce damage on top of a flat +1 to the pattern's value).

Rout and routed units

A unit at 0 HP doesn't disappear — it routs, retreats one tile, and becomes unable to attack until rallied. The standard damage formula caps at HP remaining; the killing blow only does enough damage to bring it to 0.

• Units that can't retreat (surrounded, water, ZoC) are destroyed instead.
• A routed unit at 0 HP heals at the active-heal rate next turn (5 HP/turn) once safe.

Constants pulled from XML

These come straight from globalsInt.xml and apply to combat math globally. Some are display-friendly multipliers; most are integers.

What to read next

• Unit Damage & Counters — full stat cards for every combat unit, including each unit's anti-trait modifiers.
• Unit Counters at-a-glance — the rock-paper-scissors matrix that summarises this page in one grid.
• Promotions — every numeric modifier you can stack onto effective strength.