Combat

Combat Stages
For most combat engagements, the battle will begin in day combat and follow the following set of stages. Several stages will not occur unless certain conditions are met. For Event maps, a Combined Fleet mechanic has been implemented which follows a modified combat order.

For certain nodes and events, combat begins in the Night Combat stage, then proceeds to Day combat, if certain conditions are met.

Formation Selection
With 4 or more ships in a fleet, a fleet formation must be selected before combat. The selected formation affects ship damage and hit rate.

Formation Modifier

 * The surface damage modifier applies to both shelling and torpedo attacks, but does not affect Aerial Combat or Anti-Submarine attacks.
 * Diamond Formation is only selectable as a formation with 5+ ships.
 * Flagship protection is the situation where a non-flagship ship protects the flagship from being damaged by receiving the attack instead.
 * Line Ahead has the highest offensive power for surface combat. It is the default choice for encounters after the 3rd battle node to preserve firepower because of the remaining ammo penalty.
 * Double Line is generally a good formation for heavy BB/CV fleets. There is a significant accuracy increase that benefits the typically lower accuracy carriers, while BB often still have enough firepower.
 * Line Abreast is the best formation for anti-sub purposes.
 * Echelon has not been tested extensively, but it is hypothesized to be a defensive formation for submarines.

Detection

 * Fleet LOS affects Detection rate.
 * Success increases fleet accuracy and evasion.
 * Failure prevents participation of allied planes in the aerial combat phase.

Aerial Combat
Aerial Combat Stages

Fighter Combat
$$\text {Fighter Power} = \sum^\text{All slots} \text{Floor(} \sqrt{\text{Number fighters in slot}} \times \text {Plane anti-air bonus} \text{)}$$

Fighter planes, fighter-bombers (bombers with +AA stat), and seaplane bombers participate in Fighter Combat.

The allied fleet and enemy fleet's Fighter Powers are compared to determine the result of Fighter Combat:
 * EFP: Enemy Fighter Power, FP: Fighter Power. Abbreviated to save space.
 * This calculation does not take into account any anti-air weaponry equipped on ships. Carrier anti-air stat is also not considered.
 * The percentage of planes shot down applies for both sides' respective outcomes, and is calculated per slot.
 * For example, securing Air Superiority means allied planes shoot down up to 80% of enemy planes, and the enemy under Air Incapability will shoot down up to 40%.
 * As this is applied per slot, 80% of one enemy bomber group can be shot down while a second has 0% shot down.
 * Contact can be triggered by having at least 1 carrier scout plane, seaplane scout, and/or torpedo bomber equipped. It increases damage during the bombing phase depending on the accuracy bonus of the squad triggering Contact.
 * Even if allied planes secure air supremacy, planes can still be lost (up to 10%), and the subsequent anti-air defense stage can eliminate more bombers.
 * If enemy fleet launches no fighters, and any planes are launched, the result defaults to Air Supremacy. If both sides launch no planes, then the rest of the battle is treated the same as if Air Parity was achieved.

Anti-Air Cut-In
Certain equipment combinations will provide a chance for an Anti-Air Cut-In (AACI) during the aerial combat. When activated, the cut-in CG (shown on the right) would appear before engaging the enemy fighters, but does not appear to affect the resulting air control state (AS+, AS, Air Parity or Denial). Although there's currently no conclusion on how it's applied onto the Fleet Anti-air Defense formula, a general consensus suggests the effectiveness scales with the AA stat of the ship triggering it.

Requirement: Effect: Trigger chance: With an AA Cut-In from ship with high AA stat, it is possible to obliterate all incoming bombers before they inflict any damage, and even prevent opposing carriers from shelling since they have 0 bombers left. In PVP Exercises, your opponent could do AA Cut-In to your bombers, but the animation is not shown.
 * One of the following sets:
 * Heavy main gun, Type 3 Shell, AA fire director
 * Can be supplemented with an AA RADAR
 * High-angle mount (main or secondary), AA fire director
 * Can be supplemented with an AA RADAR
 * 10cm Twin High-angle Mount + Anti-Aircraft Fire Director, AA RADAR
 * Can be supplemented with a second 10cm Twin High-angle Mount + Anti-Aircraft Fire Director
 * Akizuki has a built-in AA fire director, which allows her to trigger AACI without an AA fire director with the following setups
 * High-angle mount (any) plus either or both:
 * RADAR (any kind)
 * High-angle mount (any)
 * Provide an AoE blast on all the incoming enemy bombers, from the ship who is triggering it. (source 1, 2)
 * Luck stat does not affect the trigger rate significantly. (source, require further verification)
 * Air radar on CA does not increase the trigger chance on a large scale. (source, require further verification)
 * With the same equipment set up, Akizuki has significantly higher chance of triggering AACI.
 * According to the previous sources, the trigger chance is usually around 33%.

There are reports that enemy ships in map 6-2 might be capable of doing AACI. Other than that, there is currently no enemy ship capable to blast all your bombers with AA weapons.

Fleet Anti-air Defense
Each enemy bomber slot is assigned at random to a defending ship. Those ships then, for each assigned enemy slot, have an approximately 50% chance to shoot down enemy planes. The number of planes shot down is given by the equations below:

$$\text{Shot Down} = \text{Floor((Ship AA } + \text{Floor(Fleet Anti-air} \times \text{Formation Modifier))} \times 0.2125\text{)}$$ $$\text{Fleet Anti-air} = \text{Floor(} \sum^\text{All slots}\text{Equipment AA Bonus} \times \text{Equipment Modifier)}$$ The "Fleet Anti-Air" bonus is the sum of every equipment slot of every ship in the fleet (including the defending ship).

Equipment Modifiers

 * Any equipment that gives an anti-air bonus will contribute to shooting down enemy bombers.
 * The ship chosen to defend against bombers is not necessarily the ship targeted by that slot.
 * The ship selected to defend is not necessarily the target of the bomber. Any allied ship, including submarines, may be chosen to defend against bombers.
 * The forward sliding and machine gun animations seem to have no correlation with the calculations.
 * These calculations only apply for the allied fleet's anti-air defense; enemy fleets seem to use a different formula.

Opening Stages
The Opening Stages of combat proceed in order with the Supporting Expedition effect, the Opening Torpedo salvo, then the display of the engagement form
 * In World 5 and Event Maps, the Sortie fleet can receive a salvo of Support fire from fleets deployed on Support Expeditions. The type of supporting fire depends on the composition of the expedition fleet.
 * The Opening Torpedo Salvo is fired by Submarines over level 10, ships with the Type A Ko-hyoteki (CLTs, AVs, SS) equipped, and the Enemy Battleship Re-Class.
 * Torpedoes are fired from all ships simultaneously, and accuracy is affected by the selected Formation type.
 * The Opening stages finish with the display of the Engagement form, the orientation of the two fleets.

Engagement Form Modifier

 * Please note that all engagement forms affect both sides equally, including crossing the T ( Advantage or Disadvantage ).
 * Night battle and aerial combat are not affected by engagement forms. Torpedo salvos are affected by engagement forms.
 * Equipping a Saiun effectively makes what would have been Crossing the T (Disadvantage) become Head-on Engagement.
 * It is speculated that the Engagement form also impacts accuracy.

Day Combat

 * Day Combat consists of up to 3 phases: 1st Shelling, 2nd Shelling, Closing Torpedo
 * During the first shelling stage, the order of fire is determined by the ship's maximum range.
 * Ships are arranged in order from Very Long → Long → Medium → Short → Very Short range.
 * The shelling order alternates from allied ships to enemy ships if able. If two ships on the same side have the same range, the ship that attacks first from between them is chosen randomly.
 * The second shelling phase moves from the top to the bottom of the combat line.
 * Ships unable to attack at all in the shelling phase (i.e. submarines) will be skipped, but those normally able to attack but rendered unable to (e.g. damaged carriers) will still take actionless turns.
 * CVLs and CVs must be in good or lightly damaged condition in order to participate in shelling phases, with the exception of Armored Aircraft Carriers (e.g. Taihou) who can still attack while moderately damaged.
 * The Closing Torpedo salvo is fired by all SS(V), DD, CL(T), CA(V), AV, Bismarck drei, and the enemy Battleship Re-Class.
 * Torpedoes are fired from all ships simultaneously, and accuracy is affected by the selected Formation type.
 * Ships must not be moderately or heavily damaged to participate.

Night Combat

 * Night battle damage depends on both the Firepower and Torpedo stats for attack power. Consequently, DDs, CLs, CLTs and CAs have drastically increased strength at night.
 * Any vessel at night must not have taken more than moderate (orange) damage before attacking in order to participate in night battle.
 * Certain combinations of weapon equipment (Main Guns, Secondary Guns, Torpedoes) will cause Cut-In or Double Attacks at night, greatly increasing accuracy and/or firepower
 * Auxiliary equipment (e.g RADAR, SONAR, Depth Charges, Searchlights, Turbines, Special ammunition, Pure AA Equipment, Torpedo Bulges, and Midget-subs) will not affect the combination.
 * If night combat nodes are anticipated, it can be very helpful to utilize specialized night battle equipment such as Star Shells and Searchlight. Type 98 Recon Seaplane (Night Scout) is also an option.
 * Evasion of submarines are greatly increased in regular Night Battles, so they cannot take more than scratch damage. In battles starting at night and Combined Fleet sorties, submarines do not get the Evasion boost, so they will take damage as normal.
 * Formation damage modifiers and Engagement Form damage modifiers do not apply in Night Battle (i.e. they are always 100%).
 * As an exception, in nodes that begin with Night Battle and in Combined Fleet Night Battle, Formation and Engagement Form anti-sub damage modifiers apply.
 * The Engagement Form is not explicitly shown in Night Battle nodes.

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
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

Ship's Health Modifier
These modifiers do not affect Aerial Combat.

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

Night Special Attack Modifier
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.

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

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
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)

Artillery Spotting
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.

Critical Modifier
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.

Contact

 * 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".
 * 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 from all eligible equipped planes.
 * Different types of planes have different trigger rates. They are roughly estimated as (if only one is equipped):

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.

Combat Equipment Setup

 * Day Battle Special Attacks (Artillery Spotting)
 * Night Battle Special Attacks
 * Common Setups
 * Full Setup List

Day Battle Special Attacks (Artillery Spotting)
Artillery spotting allows your ship with seaplanes to double attack (DA) and cut-in (CI) during day battle.

Requirement Set up and Attack Modes
 * KanColle-140425-17422431.png superiority (AS) or greater achieved in aerial combat phase
 * Not in heavily damaged (大破) state
 * Ship is carrying at least 1 seaplane. (i.e. slots are not all at 0 remaining)
 * Certain equipment setup (see below)

Different set ups have chances to trigger different modes of attack
 * KanColle-140425-16133343.png are the basic setups used in the game. You don't need to exactly follow the placement (1st slot = main, 3rd slot = seaplane, etc) as long as those equipment are placed on the same ship.
 * Any other setup variation will NOT change the attack mode or damage modifier. Feel free to add another auxiliary equipment when possible.
 * Mixed Attacks provide chances for both day battle DA and CI.
 * When either CI or DA is not triggered by chance, the ship will just do a normal single attack, dealing 100% damage.
 * The enemy is capable of doing Artillery Spotting on your fleet, both DA & CI.
 * For more info on the Day Special Attack mechanics, you may visit page Artillery Spotting.

Trigger Chance of Artillery Spotting
 * The flagship has ~15% higher chance in triggering Artillery Spotting.
 * Losing Air Supremacy (AS+) to Air Superiority (AS) will lower the trigger chances by ~12%. Higher penalty for mixed attack.
 * Higher fleet total LoS (line of sight) will slightly increase the chances, around 6% ~ 10% per 100 additional FLoS. Notice that FLoS equals to the sum of LoS stats from all the ships in your fleet, and no special formula is used to calculate them.
 * Equipment set up will affect the chances (see the table above)
 * Note that in pvp, it is possible to gain AS+ without any fighter power while your opponent only uses bombers (i.e. zero fighter power) to gain AS.

Night Battle Special Attacks
Night battle special attacks allow your ship to double attack (DA) and cut-in (CI) at night. These special attacks are less demanding on the conditions, but more reliable and powerful than artillery spotting in the day.

Requirement Set up and Attack Modes
 * Not in heavily damaged (大破) state
 * Certain equipment setup (see below)

Different set ups have chances to trigger different modes of attack
 * When your set up fulfills the prerequisite for multiple attack modes, the one closer to the bottom of the list will be considered.
 * If two simultaneous / consecutive attacks are made, the total damage is displayed together but the Damage Cap (and Enemy Armor reduction) is applied separately to each attack.
 * When either DA or CI is not triggered by chance, the ship will just do a normal single attack.

Night Double Attack Chance

Has a very high (~99%) and relatively consistent activation chance. Activation rate decreases with damage states (source required), but is not dependent on luck. This typically results in more consistent and higher average damage than cut-in setup for ships with normal luck values.

Night Cut-in chance:

$$(\text{Luck} + \text{Placement Modifier} + \text{Health Modifier} + \text{Searchlight Modifier} ) \% $$


 * There appears to be diminishing returns or a hard cap on luck over 40 for three-gun cut-ins and luck over 50 for torpedo cut-ins.

Anti-Sub Warfare

Any enemy submarines will force Destroyers and Light Cruisers to target them. Cut-In and Double Attacks are ignored. In normal Night Battles, ASW damage is scratch damage only. In battles starting at night, Formation Modifiers apply.

Common Setups

 * Common ship equipment setups and their purpose
 * Destroyers
 * As destroyers do not have the ability to field seaplanes, have low firepower but high torpedo stats, and few equipment slots, their use in fleets is generally to meet composition requirements. Their common setups focus on Anti-Sub Warfare, Night Torpedo, or Fleet Anti-Air Support
 * A Mixture of SONAR and Depth Charges make your destroyers effective, accurate sub killers when enemy fleets contain Submarines.
 * On destroyers with high luck (Ayanami, Shigure, Yukikaze), 2 or 3 pieces of Torpedo Equipment will often trigger a potent Torpedo Cut-In attack in Night Battle.
 * When facing maps with many enemy fleets with carriers, destroyers can provide a considerable amount of fleet AA support using high-angle mounts and anti-air cut-in setups to reduce incoming bomber damage.
 * Light Cruisers
 * Light Cruisers gain access to the Medium size Main guns to buff their firepower as well as seaplanes (with a few exceptions with regards to seaplanes, those being CLTs, Isuzu Kai Ni, Yuubari and both of the Tenryuu class), making Artillery Spotting setups feasible and effective against moderately armored enemy vessels.
 * For light cruisers facing enemy fleets, a setup with 2 Main guns and a Seaplane offers a potent double attack in both daytime Artillery Spotting and Night Battle.
 * For fleets without air power, one medium main gun and two 15.5cm Triple Gun Mounts will maximize firepower while maintaining double attacks in Night Battle
 * The special class of the Torpedo Cruisers deserves some mention here: their specialty lies in their torpedoes and should almost always be equipped with a Type A Ko-hyoteki (to enable opening torpedo strikes). To diversify their damage output, typically two medium main guns and/or 15.5cm Triple Gun Mounts are equipped to increase shelling damage and enable Night Battle Double Attacks.
 * Before a Torpedo Cruiser's final remodel, due to limited slots it's advisable to use Type A Ko-hyoteki and a torpedo to make the most of their preemptive attack.
 * Heavy Cruisers
 * Heavy Cruisers see the introduction of 4 slot setups after remodeling and all of them feature the ability to launch seaplanes for artillery spotting. While they are still limited to the Medium main guns, their higher firepower and armor can make them solid combatants when Battleships are unavailable or overkill.
 * The go-to setup for most situations will be the 2 main guns, RADAR, seaplane setup which provides day and night double attack potential.
 * Certain Event bosses take additional damage when a ship is equipped with Type 3 Shells. As heavy cruisers have access to these, a Heavy Cruiser may find swapping the RADAR for a Type 3 Shell to be effective against such targets (see Airfield Princess).
 * In the case of a battle occurring with Night Battle first, one option is to replace the RADAR and seaplane with two torpedoes, which will lose the day battle special attacks but give the chance for powerful two-torpedo cut-in attacks.
 * Battleships
 * Battleships feature a selection of Heavy Main Guns and massive resulting firepower in addition to the potent Armor Piercing shells which can cause brutal critical hits. Setups for battleships are similar to those of heavy cruisers, with one notable addition.
 * The Armor Piercing Shells that battleships have access to allows for the highly effective 2 Main gun, AP Shell, Seaplane setup which has a more effective Artillery Spotting Cut-In, while providing better stats than secondary guns.
 * Note: Official tweets state that overuse of cannons larger than what a BB is meant for will make it "overweight" and incur a "minor" accuracy penalty. (I.e. Too many 46cm or even 41cm cannons on Fast Battleships such as Kongou-class and Bismarck.)
 * As with Heavy Cruisers, the Type 3 Shell setup is effective against installation-type/land base enemies.
 * Carriers
 * Planes. Enough Fighters to achieve Air Superiority or Supremacy, fill out with Torpedo Bombers on larger slots for preemptive bombing damage and/or Dive Bombers on smaller slots for shelling damage.
 * Torpedo Bombers and Dive Bombers are roughly equivalent to each other. While Torpedo Bombers have the advantage in the preemptive aerial bombing, their damage are dependent on number of surviving planes, making air superiority very important for them. In cases where Air Superiority is not feasible, using more Dive Bombers may prove more effective.
 * It is possible to equip Secondary Guns like the 15.5cm Triple Gun Mount or the special SCAMP to increase the carrier's range and put it higher in the Range Order shelling phase, which can be very useful for prioritizing the CV(L) damage when in a DD heavy fleet.
 * To save bauxite (especially in exercises against other fleets), a combination of two 15.5cm Triple Gun Mount and/or SCAMP with a Saiun and a single bomber in the 4th slot can allow powerful shelling attacks at the cost of opening airstrike potency.

Full Setup List

 * What follows is an extensive list of possible equipment setups related to Artillery Spotting and Night Battle attacks.


 * Yellow: Cut-In or Double Attack Possible

Victory Conditions

 * Perfect S
 * All enemy ships sunk and no damage taken.
 * S (Victory)
 * All enemy ships sunk and no allied ships sunk.
 * A (Victory)
 * Required number of enemy ships sunk (see below) and no allied ships sunk.
 * B (Tactical Victory)
 * Sinking the enemy flagship guarantees at least a B as long as no allied ships are sunk.
 * Enemy flagship sunk, friendly ship sunk and number of friendly ships sunk < number of enemy ships sunk.
 * Damage gauge at least 2.5 times higher enemy damage gauge.
 * This rate is the minimum requirement to clear maps without boss gauge.
 * C (Tactical Defeat)
 * Didn't clear any of the conditions for A or B, but enemy took over a certain amount of damage.
 * Damage gauge higher than enemy gauge, but not reaching 2.5 times as much.
 * Friendly ship sunk, damage gauge higher than enemy, but not 2.5 times as much.
 * Friendly ship sunk, enemy flagship sunk and number of friendly ships sunk lower than number of enemy ships sunk. It is possible to clear maps with boss gauges (eg. 4-4, 5-3, event maps) with a C if the enemy flagship is sunk.
 * D (Defeat)
 * Enemy took less than a certain amount of damage.
 * Both sides taking 0 damage is also D.
 * If your fleet consist only 1 ship and it is reaching Heavy Damage without meeting any winning requirements, it will instantly judged as D as well.
 * Damage gauge lower than enemy gauge.
 * Friendly ship sunk, not all enemy ships sunk, and gauge lower than enemy gauge.
 * E (Defeat)
 * Over a certain number of friendly ships sunk. (see below)
 * Friendly ship sunk while not meeting any victory conditions.
 * No damage done to enemy, while taking over a certain amount (Never happens in a fleet of 1).