Combat/Damage Calculation

Damage Calculations
Main Formula

Basic Attack Power

 * According to wikiwiki, multiple SONAR/Depth charges do not boost the ASW Bonus (i.e. 2 of each still makes the bonus 1.15)

Pre-Cap Modifiers
list= These are the factors directly applied to your ship's attack power. Effects from the modifiers are multiplied cumulatively.
 * Formation Modifier (see "Damage modifier")
 * Engagement Modifier
 * Health Modifier
 * Plane Scaling (Opening air strike only)
 * Night Special Attack Modifier
 * Anti-Installation Attack Modifier

These modifiers do not affect Aerial Combat.
 * -|Ship's Health Modifier=


 * -|Plane Scaling=

Applied on bombers during the opening air strike. These are the random numbers multiplied to the plane's bombing attack power.

Certain Equipment setups have a chance to trigger special attacks at night, giving boost to both attack power and accuracy. This stage is usually the most rewarding / dangerous because both sides have drastically increased attack power.
 * -| Night Special Attack Modifier =

The ship must be able to participate in the night battle in order to trigger the special attacks.


 * -| Anti-Installation Attack Modifier =

At present, this is only applied for two types of equipment: Note also that against installations, only Firepower is taken into account; in night battle, even though attack power is normally the sum of Firepower and Torpedo, for installations specifically the Torpedo stat is disregarded.
 * The Type 3 Shell multiplies Firepower by 2.5.
 * The WG42 (Wurfgerät 42) adds 75 Firepower. In the event both are present, this is added after the Type 3 Shell's effects, but before the sum is multiplied by the other modifiers.

Attack Power Cap
Applies after the pre-cap modifiers. This is a soft limit on your effective attack power.

Condition : If your pre-cap attack power exceeds: The Attack Power Cap will be activated, nerfing the effectiveness of your pre-cap attack power. The calculation is:
 * 150 for Day Battle
 * 300 for Night Battle
 * 100 for Anti-sub attacks

$$\text {Attack Power After Caps} = x + \sqrt {\text {Pre Caps Attack Power} - x}$$, Where x represents the attack power cap.

Daytime Attack Cap (150) often makes it important to utilize Artillery Spotting since they boost your attack power after the cap, Night Combat can be very dangerous and/or rewarding due to having a very high cap (300) and the inclusion of torpedo to firepower for the basic attack power calculation.

Post-Cap Modifiers
list= In damage calculation, Post-cap modifiers apply after the cap, but before enemy armor reduction. Thus they are very effective approach to boost your damage output (esp. against heavy armor enemies).

Currently, the post-cap modifiers are from:
 * Artillery Spotting (aka. Day time special attacks)
 * Critical Damage
 * Contact (Opening air strike)
 * AP Shell (against certain targets)
 * Aircraft Proficiency

Certain equipment setups provide a chance to trigger special attacks during day battle, giving boost to both attack power and accuracy. The damage modifiers are applied after the cap (150), thus very effective against heavy armor targets. Note that the ship requires at least 1 seaplane on board to perform Artillery Spotting.
 * -|Artillery Spotting =

Most forms of attack (Torpedo, Shelling, Anti-Submarine, Preemptive Bombing) have a chance to crit the target. The damage modifier applies after the cap. It should be noted that the critical message always appears when damage dealt is greater than or equal to 40, regardless of whether the 150% modifier was applied or not. On the other hand, the critical message will never appear when damage dealt is less than or equal to 14, even if the 150% modifier was applied.
 * -|Critical Modifier=

Contact takes place during the Aerial Combat phase. It increases bombing damage for all allied bombers. When successful, an image of the squadron performing contact is shown in the opposing fleet's formation indicator, with the text "触接中". Different types of planes have different trigger rates. They are roughly estimated as (if only one is equipped):
 * -|Contact=
 * Trigger conditions:
 * More air control than Air Denial
 * At least one carrier scout plane, seaplane scout, or torpedo bomber equipped.
 * Seaplane bombers, Type 3 Spotter, and Ka-type Autogyros cannot perform contact.
 * It's thought that each carrier scout plane, seaplane scout, and/or torpedo bomber slot equipped is given a chance to trigger contact. Once successful, the bonus applied is chosen at random with weighting preferential towards higher modifiers from all eligible equipped planes.


 * -|Contact Damage Modifier=
 * The damage increase depends on the +accuracy bonus of the squadron performing contact.

Remaining Ammo Modifier

 * In general, two bars of will be used in Day Battle for all ships, regardless of whether they attack or not.
 * The Remaining Ammo Modifier affects all phases, including the opening Aerial Combat Phase.
 * When entering night battle, the Remaining Ammo Modifier on a vessel remains same as the previous day battle. One bar of is used for all ships in Night Battle, regardless of whether they attack or not.
 * Because most battles will consume 2 bars of ammunition each, try to engage the boss before the 5th battle, or else achieving victory becomes unlikely (but not impossible).
 * When attempting to defeat boss nodes, avoid night battles and whirlpools on the way.
 * Whirlpools will decrease either or  bars of your sorted fleet, which can be disadvantageous in long sorties.  Equipping one or more ships with RADAR can help reduce losses taken from these.
 * Submarine-only nodes on limited-time event maps do not consume ammo in Day or Night Battle.

Player Ship Protection Mechanisms
While the above formulas and statements are generally true for damage taken by a player's ships, there are additional limits that apply to friendly units only. These protection mechanisms are important for game balance and to protect your fleet from sinking.
 * For ships entering battle at chuuha (orange) or higher HP:
 * Damage taken cannot reduce HP below 1.
 * Any further hits will become misses.
 * For flagships, as well as ships with 20 morale or more (i.e. not red face):
 * If damage taken exceeds a ship's current HP, then instead of taking full damage, the damage of the current attack is limited to 50%-79% (rounded down) of current HP.
 * For multi-hit attacks, such as night battle torpedo cut-in attacks, each hit is calculated separately.
 * This can occasionally help ships avoid taiha (red HP), because it narrows the range of damage where it is possible to be hit into taiha.
 * For ships with at full hp and an odd hp total, it is occasionally possible to stop damage at lightly damaged.