Combat

Combat Stages

Stage	Notes
Detection	Requires planes or high detection stat. Success increases hit rate and evasion. Failure leaves you unable to participate in air combat phase.
Air Combat
Supporting Fire	Map 5, requires sortie support expedition.
Opening Torpedo Salvo	Requires midget subs or submarines over level 10
Shelling, 1st Round (Range Order)	Any carrier using bombers to attack during this phase must not have taken more than light damage in order to participate in the phase.
Shelling, 2nd Round (Lineup Order)	Only occurs when one or both sides has a battleship, or the enemy contains one of the special ship classes: 鬼, 姫, 戦鬼, or 戦姫.
Torpedo Salvo	Must not have taken more than light damage to participate.
Night Combat	Attacks occur in lineup order from top to bottom, alternating between sides.

Night Combat Attacks

• Night battle damage depends on either the Firepower or Torpedo (or both!) stats for attack power, depending on the specifc attack type.  Consequently, DDs, CLs, CL(t)s and CAs have drastically increase strength at night.
• Any vessel at night must not have taken more than moderate (orange) damage before nighttime in order to participate in night battle.
• Main Gun = Red guns or 10cm High-angle Gun
• Secondary (Sub) Gun = Yellow guns / 12.7cm High-angle Gun / 8cm High-angle Gun
• You can add other equipment like radar, turbines, special ammo, or repair teams to remaining empty slots on a ship; these equipment types will not affect the combination.

Examples of cut-in attack equipment setups

3 main guns		2 main guns		1 main gun
						Just 2 torpedos
		+		+
		1 sub gun		1 torpedo		Onealso equippable
Noorequipped

Examples of double attack equipment setups

1 main gun		2 main guns		2 sub guns
+
1 or more sub guns
Noequipped		Noorequipped		Onealso equippable

Complete night battle attack type table

Type	Main	Secondary	Torpedo	Notes
Cut-In			2+	Torpedo Attack
	3+			Shelling
	2	1+
	1-2		1	Combined Attack
Double Attack	2	0	0
	1	1+	0
	0	2+	0-1	Secondary Gun Double-Attack, Torpedo doesn't fire
Single Attack	Results from failing to meet equipment requirements, or other attacks random chance at failing.  Fires with gun or torpedo in highest equipment slot.
Anti-Submarine	Any enemy submarines will force Destroyers and Light Cruisers to target them.  Cut-In and Double Attacks are ignored.

Special night battle attack damage

Cut-in attacks

Weapon Type	Magnification
2 torpedos	The 2 consecutive attacks - total 150%
1 main gun, 1 torpedo	The 2 consecutive attacks - total 130%
3 main guns	200%
2 main guns, 1 secondary gun	175%

Double attacks

2 consecutive attack - total 120%. Always procs while cut-ins are only by chance and also affected by luck stat. (Japanese wiki confirmed that Yukikaze has a more chance of doing cut-ins than Shimakaze)

Effects of ship damage

Amount of damage on a ship will affect its performance.

Minor damage (小破) or less	No effect on performance
Moderate damage (中破)	Attack power, accuracy, and evasion are slightly decreased
Heavy damage (大破)	Attack power, accuracy, and evasion are significantly decreased

On attack power

Damage	Modifier
Minor damage (小破) or less	100%
Moderate damage (中破)	70%
Heavy damage (大破)	40%

Modifier does not affect plane attacks (needs confirmation, because I'm not sure about google translate. source: wikiwiki)

Factors involved in damage calculation

Formation

Formation	Modifier
Line Ahead	100%
Double Line	80%
Diamond	70%
Echelon	60%
Line Abreast	60%

Night battle and air combat are not affected by formation choice.^[source?]

Engagement forms

Form	Modifier
Parallel Engagement (同航戦)	100%
Head-on Engagement (反航戦)	80%
Crossing the T (Advantage) (T字戦有利)	120%
Crossing the T (Disadvantage) (T字戦不利)	60%

• Night battle and air combat are not affected by engagement form.
• The engagement form attack modifier affect both your fleet and the enemy fleet.
• Crossing the T (Disadvantage) can be avoided by equipping a 彩雲 Saiun (Carrier-based recon plane).

Illustration of engagement forms

Parallel Engagement

The course of the player's fleet and the enemy fleet are the same.

Fleet A	→	→	→	→	→	→
Fleet B	→	→	→	→	→	→

Head-on Engagement

The course of the player's fleet and the enemy fleet are opposite each other.

Fleet A	→	→	→	→	→	→
Fleet B	←	←	←	←	←	←

Crossing the T

The course of the player's fleet and the enemy fleet are perpendicular to each other (that's 90 degrees, which results in a T figure).  A fleet is in disadvantage if it is coming from 「｜」direction, and is in advantage it is is coming from 「―」direction.

(Historically, the point of this was for the 「―」fleet to bring as many guns to bear on the enemy while limiting the firepower of the enemy that can only use guns mounted forward.)

→	→	→	→	→	→
		↑
		↑
		↑
		↑
		↑

Critical Attack damage

Attack Type	Attack modified by...
Normal Attack	100%
Critical Hit!	150%

It should be noted that the critical message always appears when damage dealt is greater than or equal to 40. (If, on the other hand, the critical message appeared when the damage dealt was less than 40, then it was a critical hit.)

Amount of Ammunition Remaining (unconfirmed)

Ammunition Amount	Magnification
5 or more ammo bar	100%
4 ammo bar	80%
3 ammo bar	60%
2 ammo bar	40%
1 ammo bar	20%
0 ammo bar	Only Kasudame カスダメのみ

(Help: Confirmation needed if the wiki is indeed saying ammo bar. And what are game eyes? And what is Only Kasudame? Here's the link)

Magnification also affect air warfare. 

Magnification is the same for day and night battle of the battle.

User Amanies is asking for help: Everything is taken from here. Some sections weren't added because I felt that the google translation wasn't accurate (or I didn't understand it at all).

Victory Conditions

Perfect S

• No damage taken, all enemy ships sunk.

S (Victory)

• All enemy ships sunk.

A (Victory)

• No friendly ships sunk and required number of enemy ships sunk.
  • Sink 4 of 6, 3 of 5, 2 of 4, 2 of 3, or 1 of 2.

B (Tactical Victory)

• Enemy flagship sunk.
• No damage taken, and enemy took over a certain amount of damage.
• Damage gauge at least twice enemy damage gauge.
• Friendly ship sunk, specified number of enemy ships sunk, and damage gauge twice enemy gauge.
• Friendly ship sunk, enemy flagship sunk, and damage gauge twice enemy 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 twice as much.
• Friendly ship sunk, damage gauge higher than enemy, but not twice as much.

D (Defeat)

• Enemy took less than a certain amount of damage.
  • Both sides taking 0 damage is also D.
• 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.
• Friendly ship sunk while not meeting any victory conditions.
• No damage done to enemy, while taking over a certain amount.