Fight System

Fights are a core concept of the game. In a fight the side with the higher total strength always wins. The basis of strength is the attack and defense value of the units, which then can be increased with various buffs.

Attack & Defense

Each unit has an attack and a defense value. Units with a high attack but low defense value are often called "offensive units" and units with a high defense but low attack value are called "defensive units". Of course it's more efficient to use offensive units to attack and defensive units to defend, but it's possible to attack or defend with each unit.

In a fight, the strength of a unit depends on whether it is attacking or defending. For an attacking unit only the attack value counts — the defense value is irrelevant. And in defense only the defense value counts.

Example

10 Guard Nakis (att: 60, def: 20) attack 10 Grass Spirits (att: 15, def: 60).

Because the Guard Nakis are attacking, take the attack value to calculate the strength of the attack:

10 * 60 = 600 (amount of units * attack value = strength)

For the defending Grass Spirits, take the defense value to calculate the strength of the defense:

10 * 60 = 600

The raw strength is equal — but the Guard Naki is an Infernal unit and gets the effectiveness bonus against the Primal Grass Spirits, so in this fight the attacker would win.

Buffs

There are multiple ways to increase the strength of your attacking or defending units. Some buffs apply to the whole army, some buffs only to a specific unit. The most important sources are:

Effectiveness buff (combat types)
Field upgrades (attack / defense)
Runes
Artifacts
Special unit abilities
Legend perks
Airship bonus (+100% attack when attacking from a starter field)

Effectiveness Buff

Units get an effectiveness buff of up to +100% when they fight against units of the combat type they counter (no matter whether attacking or defending). Unlike all other buffs, the effectiveness buff is applied multiplicatively on top of the summed other buffs. Check out the effectiveness system for more details.

Field Upgrades

Fields can be upgraded with attack and defense upgrades (up to level 4 each). Attack upgrades are only considered when attacking from that field, defense upgrades only when this field gets attacked. Field upgrades always buff the whole army on the field and are counted additively with other buffs. Check out Field Buffs for the exact values, and note that special upgrades like healing or plague are also available.

Runes & Artifacts

Runes and artifacts increase the strength too. They are added additively to other buffs and buff the whole army. Offensive runes and artifacts apply to attacks only, while defensive runes and artifacts only apply in defense.

Special Units & Legends

Special units have their own abilities which can increase the attacking or defending strength — for example the Ovivi defense aura or the Teryx max-range attack boost. Some abilities boost the whole army, others only the special unit itself. On top of that, some Legends provide fight-related perks, like a portal attack bonus or counter-attack charges.

Example

	units	buffs
Attacker	100x Guard Naki, 50x Druid Naki	30% field upgrade 6% runes
Defender	15x Elder Spirit, 200x Nyxi	30% field upgrade, 10% runes

To find out who wins the fight, the raw strength is calculated first: for each unit, multiply its amount by the corresponding value (attack value for attackers, defense value for defenders). Then all regular buffs are summed up, and the effectiveness buff is applied multiplicatively on top.

Attacker

Raw attack strength: 100 * 60 + 50 * 30 = 7'500. The Guard Nakis (Infernal) contribute 80% of that strength and the whole defending army is Primal, so the effectiveness buff is 80% * 100% = 80%. The Druid Nakis (Umbral) add no effectiveness.

Total strength: 7'500 * (1 + 36%) * (1 + 80%) = 18'360 (raw strength * regular buffs * effectiveness)

Defender

Raw defense strength: 15 * 75 + 200 * 10 = 3'125. The defenders are all Primal, which counters Astral — but the attacker brings no Astral units, so the defender gets no effectiveness buff.

Total strength: 3'125 * (1 + 40%) = 4'375

The attacker's total strength is far greater (18'360 > 4'375), so the attacker wins the fight. Note how the effectiveness buff decided this fight — with reversed combat types the result would look very different.

If you want to simulate a fight and want to know how many units survive, check out the fight simulator inside the game.

Tips & Tricks

Field upgrades

Attack upgrades only help when attacking from that field, and defense upgrades only when the field gets attacked. Upgrade your main staging fields with attack upgrades and your key production or choke-point fields with defense upgrades. The healing upgrade is very powerful if you win the defense — surviving units get healed — but does nothing if you lose. The plague upgrade punishes any attacker by killing a part of their surviving units.

Effective units

Using effective units can make a huge difference in fights. It's worth sending some Spotter Nakis first, to know which units the defender has. And when you have to defend but know which unit type the attacker is sending, it can be worth moving countered units away, so the remaining units defend with a higher buff.