Combat/Night Battle
Night Battle Breakdown
When the fleet pursues the enemy into Night Battle (夜戦, yasen), or enters special Nodes such as Night Nodes or Night to Day Nodes, the fleet will fight at night.
The Night Battle has the following structure:
- Friendly Fleet (event only)
- Support Expedition (if the battle starts at night only)
- Night Contact and Spotting
- Night Shelling Phase
In case neither fleets meet the requirements, the sub-phase will be skipped.
Night Contact and Spotting
When the fleet is equipped with certain equipment, additional effects are triggered for the duration of the Night Battle. The relevant equipment and their effect are listed below.
- More information on the actual effects on cut-in rate of each piece of equipment can be found in the Night Shelling Special Attacks section.
- See Accuracy, Evasion and Criticals for details on other effects.
| Equipment | Effect | Requirements |
|---|---|---|
 Star Shell
|
|
|
 Prototype Night Zuiun (Attack Equipment)
|
| |
 Searchlights 
|
|
|
 Skilled Lookouts 
|
|
|
 Night Recons  
|
|
|
Night Shelling Phase
Following the battle preliminary stages, Night Shelling proper will begin. Similar to Day Battle, attacks performed by ships are shelling attacks.
Some rules are applied to shelling attacks:
- Attack power is defined by
+ 
stats instead of only .
- It is often represented with the
"Night Battle Power" (Yasen) icon. - If the enemy is unaffected by torpedoes, such as installations, only is used instead.
- It is often represented with the
- Heavily damaged (大破) and sunk ships are unable to participate in battle.
- CV(B/L) are unable to participate in battle, unless specific requirements are met. See Carrier Night Attacks.
- Shelling attacks that target submarines will always deal 0 damage, and default to scratch damage, making it impossible to sink submarines during Night Battle.
- This rule is void if the player fleet is a Combined Fleet.
- Friendly Fleets also ignores this rule and may damage submarines.
- Ships with 0 stat are unable to participate in night battle.
- Currently, this is only observable against the Wa-Class Transport Ship.
- Some ship types gain bonus Evasion
:
- CA(V) gain +5 evasion.
- DD gain +10 evasion if equipped with a Skilled Lookout and a Surface Radar.
- CA(V) equipped with IJN 20.3 cm guns
gain special Hidden Fit Bonuses.
The firing order is defined when the Night Shelling Phase starts, and in contrast to Day Battle, will not skip over ships unable to attack, such as damaged/deplaned carriers, and sunk/evacuated ships, those ships performing an actionless turn instead.
In addition to that, Night Battle is not affected by the Day Battle's Engagement.
Carrier Night Attacks
Normally carriers cannot attack at night unless certain conditions are fulfilled. There are three different kinds of carrier night attacks: Standard Shelling, Swordfish Night Attacks, and Carrier Night Air Attacks.
This is not to be confused with Carrier Cut-In Attacks which are for daytime shelling.
Trigger Requirements
- 1. Standard Shelling
- Graf Zeppelin
(both remodels), Taiyou-class Kai Ni
, Saratoga
(base only), and Kaga Kai Ni Go
are able to attack at night with guns regardless of equipment. - This attack can be triggered even when moderately damaged (中破).
- The attack power is calculated using the surface night battle damage formula.
- Because of this, these attacks are weak.
- There is no critical multiplier bonus from plane proficiency.
- If the enemy fleet contains a submarine, the light carriers will be forced to target them.
- May be set up to activate Double Attacks and Cut-Ins.
- 2. Swordfish Night Attack
- This is just limited to Ark Royal
(both remodels) when equipped with a Swordfish
. - This attack cannot be triggered when moderately damaged (中破).
- The attack power is calculated using the surface night battle damage formula but only taking into account Ark Royal's base firepower and the Swordfish's stats.
- There is a critical multiplier bonus from plane proficiency.
- May be set up to activate Double Attacks and Cut-Ins.
On a side note, unlike the browser version, on the arcade version the attack is very powerful.
- 3. Carrier Night Air Attack
- When equipped with a
NOAP
along with at least one 
Night Plane, all carriers are able to perform carrier night air attacks.
- Night Carriers (CVN) are CV/CVL capable of Carrier Night Air Attacks without needing a NOAP . They are Saratoga Mk.II
, Akagi Kai Ni E
, Kaga Kai Ni E
, and Ryuuhou Kai Ni E
.
- Night Carriers (CVN) are CV/CVL capable of Carrier Night Air Attacks without needing a
- This attack cannot be triggered when moderately damaged (中破).
- Armoured carriers can still trigger the attack at moderate damage.
- The attack power is calculated using the carrier night air attack formula.
- Only the base stats of the carriers and the stats of the night planes are taken into account.
- Slot size plays a role in determining damage.
- Planes in slots that have been reduced to 0 are ignored.
- It can trigger regardless of the result of the fighter combat phase in day.
- It can trigger even if no bombers are left.
- There is a critical multiplier bonus from plane proficiency.
- Light carriers will ignore submarines to target surface ships with this attack.
- May activate Night Carrier Cut-Ins.
Night Special Attacks
When using special equipment setups, ships may perform one of multiple special attacks at night. These attacks are often referred to as Cut-Ins due to the way the equipment is displayed on the screen before the attacks are performed. Particular cut-ins are often referred to by their acronym, such as TCI for Torpedo Cut-In, GCI for Gun Cut-In, DA for Double Attack, etc...
Compared to Day cut-ins (Artillery Spotting), Night cut-ins do not require any particular Air State, relying solely on the equipment restrictions and the stats of the ship performing it. Do note that the specific equipment being shown during the cut-ins animation have no influence on the damage output.
Cut-ins may be activated during a ship's turn and will override its normal single attack.
In addition, all "Special Attacks" (Touches) can trigger at night, with the "Kongou-class Night Assault" being only available during night battle.
Setups and Attack Types
Different setups have different conditions, trigger rates, damage, and number of hits. Cut-ins are solely determined by the attack's prerequisites.
For a given cut-in, any other equipment can be added to the remaining slots. Be wary that adding certain equipment may change the Cut-ins rolled for. If the setup fulfills multiple prerequisites, the Cut-in closer to the bottom of the list will be used. Additionally, each ship will roll for "New Type" Cut-ins first, if possible.
is used to indicate a Main Gun.
is used to indicate a Secondary Gun.
is used to indicate a Torpedo (including Submarine Torpedoes).
- Sub_LM is used to indicate a Late-Model Submarine Torpedo specifically.
Surface is used to indicate a Surface Radar- is used to indicate Night Seaplane Bomber.
- Custom icons are used for Carrier Cut-ins for clarity's sake.
is used to indicate either a 
Swordfish
or 
Iwai FB
.
is used to indicate a Night Fighter.
is used to indicate a Night Torpedo Bomber.
is used to indicate the Photobomber
.
Special attacks that hit twice will roll independently to determine hit, critical chance, and armor penetration. Although their animations appear as single hits, Torpedo Cut-In, and Mixed Torpedo Cut-In are actually composed of 2 separate hits, with their damage added together in-game.
"New Type" Cut-ins
The "New Type" Cut-ins are the Cut-ins introduced with the implementation of Saratoga Mk.II onwards. From top to bottom, each eligible Cut-in will be rolled if the previous roll has failed. If all rolls fail, then an additional single roll for a "Original Type" Cut-in is performed.
Do note that Night Carrier Cut-ins require a CV(L/B) with Night Operation capabilities by either equipping a NOAP or being a CVN.
- Carriers that can perform Surface Shelling attacks at night will not perform Carrier Cut-ins without said Night Operation capabilities.
- Night Zuiun CI
(Exact effects are still under investigation)
- Can only be triggered on BBV, CAV, CL, or AV[1].
- The ship must not be more than lightly damaged (小破).
- Performs 2 attacks against random enemies.
- The same enemy can be targeted twice.
- Drops a Star Shell during the attack.
If not applicable, ships will skip rolling for "New Type" Cut-ins altogether and only roll for "Original Types" instead.
| Attack Type | Prerequisites | Notes | Pre-cap Damage Modifier | Accuracy Modifier[1] |
Hits | Chance for 2nd Hit[2][3] (LV 80+ DD only) |
Trigger Rate [math]\displaystyle{ \text{Base}_\text{attack} }[/math] (lower is better) |
|---|---|---|---|---|---|---|---|
| Destroyer Cut-ins | Surface
|
1.3 | 1.1 | 1 or 2 | 65% | 115[4] | |
With 12.7cm Mod D K2
|
1.625 | ||||||
With 12.7cm Mod D K3
|
1.706 | ||||||
| With 2 12.7cm Mod D K2
|
1.820 | ||||||
| With both 12.7cm Mod D K2 & K3
|
1.911 | ||||||
| With 2 12.7cm Mod D K3
|
2.002 | ||||||
| Surface
|
1.2 | 1.2~? | 50% | 140[5] | |||
| With 12.7cm Mod D K2
|
1.5 | ||||||
| With 12.7cm Mod D K3
|
1.575 | ||||||
| With 2 12.7cm Mod D K2 [6]
|
1.680 | ||||||
| With both 12.7cm Mod D K2 & K3 [6]
|
1.768 | ||||||
| With 2 12.7cm Mod D K3 [6]
|
1.848? | ||||||
|
Requires TSLO
|
1.5 | 1.37~? | 87.5% | 125[7] | ||
|
Requires TSLO
|
1.3 | ? | ~55%? | 122[8] | ||
| Carrier Cut-ins[9] |
|
 = 
|
1.25 | ? | 1 | N/A | 105[10] |
|
|
1.2 | 120[10] | |||||
| OR
|
1.2 | 120?[10] | |||||
|
|
1.18 | 130[10] | |||||
| Night Zuiun Cut-ins | Surface
|
Is affected differently by night equipment see below | 1.36 | 1.02~1.11 | 2*Will fire at 2 random enemies | N/A | 135[11] |
|
|
1.32 | ||||||
| Surface
|
1.28 | ||||||
|
|
1.24 | ||||||
- Derivated set-ups
When using an SLO or TSLO in the Reinforcement Expansion, it is possible to "mix" the Destroyer Cut-ins, making 2 cut-ins available to trigger at once, and so increasing the odds of having at least one that activates during Night Battle.
Those set-ups are:
- "GTRL": Surface
- "DTRL": Surface
GTRL is sometimes referred to as "GUiTaRSolo" for "Gun, Torp, Radar, and Skilled Lookouts (SLO)".
Do note that if a DD is equipped with a Surface Surface Radar AND a Skilled Lookout , then it gain a post-cap evasion bonus during Night Battle.
Original Cut-ins
In contrast with the "New Type" Cut-ins, "Original" Cut-ins are only rolled once, even if multiple setup prerequisites are met. The setup used will be the top-most that meets the prerequisites. If this roll fails, the ship will perform a Single Attack.
| Attack Type | Prerequisites | Notes | Pre-cap Damage Modifier |
Accuracy Modifier[1] |
Hits | Trigger Rate [math]\displaystyle{ \text{Base}_\text{attack} }[/math] (lower is better) |
|---|---|---|---|---|---|---|
| Gun Cut-in |
|
+ Any on the remaining slots | 2 | 2[2] | 1 | 140 |
| Mixed Gun Cut-in |
|
No additional
|
1.75 | 1.5[2] | 130 | |
| Submarine Cut-ins | Sub_LM 
|
With Late-Model Sub Torps ONLY | 1.75 | ? | 2 | 105[3] |
| Sub_LM Sub_LM
|
1.6 | 110[4] | ||||
| Torpedo Cut-in |
|
+ Any on the remaining slots | 1.5 | 1.5 | 122 | |
| Mixed Torpedo Cut-in |
|
Additional allowed
|
1.3 | 1.5[2] | 115 | |
| Double Attack |
|
No additional
|
1.2 | 1.1 | - | |
|
|
Additional allowed
| |||||
|
|
Additional allowed
|
Single Attack
If all rolls fail or the ship meets no Cut-in requirements, then it will perform a "Single Attack", a default 1 hit shelling attack, with no particular damage or accuracy modifier.
Trigger Rates
The chance of successfully rolling a Cut-in and performing the attack is given by:
[math]\displaystyle{ \text{CI %} = \left[ \dfrac{\text{Base}_\text{ship}}{\text{Base}_\text{attack}} \right] \times 100 }[/math]
Where:
[math]\displaystyle{ \text{Base}_\text{ship} = \lfloor 15 + \text{Luck} + 0.75 \times \sqrt{\text{Level}} + \text{Modifiers}\rfloor }[/math] , if the Ship's Luck stat is less than 50.
[math]\displaystyle{ \text{Base}_\text{ship} = \lfloor 65 + \sqrt{ \left( \text{Luck} - 50 \right) } + 0.8 \times \sqrt{\text{Level}} + \text{Modifiers}\rfloor }[/math], if the Ship's Luck stat is 50 or greater.
Modifiers is the sum of various equipment modifiers. Do note that modifiers change based on the Cut-in that is being used:
| Modifier | Value | |||
|---|---|---|---|---|
| Allied | Night Zuiun CI |
Enemy | ||
| Placement | Flagship | 15 | 0 | |
| Other | 0 | |||
 Health
|
moderately damaged (中破 Chuuha) |
18 | 0 | |
| All other health states | 0 | |||
| Searchlights [1]
|
- | 7 | -10 | -5 |
| Star Shell Prototype Night Zuiun (Attack Equipment)
|
- | 4 | -10 | -10 |
| Skilled Lookouts
|
- | 5 | 8 | 0 |
| Torpedo Squadron Skilled Lookouts [2]
|
Allied DD/CL(T) | 8 | 0 | |
| Allied Other | 0 | |||
[math]\displaystyle{ \text{Base}_\text{attack} }[/math] is the Value used by each type of Cut-in. See the above tables for value.
- Notes
- The effect of
over 51 is negligible due to diminishing returns, thus going above such value is generally discouraged. - The formula used above was datamined from KanColle Kai and is corroborated by test results in the browser version.