Accuracy, Evasion and Criticals

This page is to provide an in-depth look into the hit rate mechanics in-game for single/combined fleets and land-based air squadrons. The formulas presented in this page are still subject to change as more testing is done.

  • Please note that all formulas between [math]\displaystyle{ \lfloor \ \rfloor }[/math] are rounded down.

Hit Rate

The hit rate is used by all attacks.

[math]\displaystyle{ \text{Hit %} = \bigl\lfloor \text{Hit}_\text{cap} \bigr\rfloor + \text{Acc}_\text{proficiency} +1 }[/math]

Where, the Capped Hit Rate [math]\displaystyle{ \left( \text{Hit}_\text{cap} \right) }[/math] is:

[math]\displaystyle{ \text{Hit}_\text{cap} = \text{cap}_\text{max}\left( \text{cap}_\text{min} \left(\text{Accuracy}_\text{atk} - \text{Evasion}_\text{def}\right) \times \text{Morale}_\text{defender} \right) }[/math]

  • [math]\displaystyle{ \text{Accuracy}_\text{atk} }[/math] is the calculated accuracy of the attack. Please see below for the various accuracy formulas.
  • [math]\displaystyle{ \text{Evasion}_\text{def} }[/math] is the calculated evasion of the defending ship. Please see below for the various evasion formulas.
  • [math]\displaystyle{ \text{Morale}_\text{defender} }[/math] is the morale state modifier of the defending ship. Morale is referring to the value of attacking timing, not the value before entering battle. Please see Morale and Fatigue for more details.
    • Sparkled is 0.7,
    • Normal is 1.0,
    • Orange is 1.2,
    • Red is 1.4.
  • [math]\displaystyle{ \text{Acc}_\text{proficiency} }[/math] is the average plane proficiency accuracy bonus. Please see Plane Proficiency for more details.
    • The average is calculated only from dive bombers, torpedo bombers, seaplane bombers and large flying boats.
    • The value is 12 for ❱❱ ranked planes.

Hit Rate Caps

There is a minimum and maximum hit rate in the game.

  • The minimum of [math]\displaystyle{ \text{cap}_\text{min}\left(x\right) }[/math] is 10.
  • The maximum of [math]\displaystyle{ \text{cap}_\text{max}\left(x\right) }[/math] is 96.

Notes:

  • Hit rate has an effective minimum of 11% and a maximum of 97%.
  • Plane proficiency is the only factor that allows a ship to go beyond 100% hit rate.

Critical Hit Rate

The following are the various formulas for determining critical hits for attacks.

  • Shelling/ASW (including carriers): [math]\displaystyle{ \lfloor 1.3 \times \sqrt{\text{Hit}_\text{cap}} \rfloor + \text{Crit}_\text{proficiency} + 1 }[/math]
  • Torpedo: [math]\displaystyle{ \lfloor 1.5 \times \sqrt{\text{Hit}_\text{cap}} \rfloor + 1 }[/math]
  • Airstrike: [math]\displaystyle{ \lfloor 0.2 \times \sqrt{\text{Hit}_\text{cap}} \rfloor + \text{Crit}_\text{proficiency} + 1 }[/math]
  • Night Battle (including carriers): [math]\displaystyle{ \lfloor \left(1.5 + \text{Const}_\text{contact} \right) \sqrt{\text{Hit}_\text{cap}} \rfloor + 1 }[/math]
  • Shelling Support: [math]\displaystyle{ \lfloor 1.0 \times \sqrt{\text{Hit}_\text{cap}} \rfloor + 1 }[/math]
  • Airstrike Support: [math]\displaystyle{ \lfloor 0.2 \times \sqrt{\text{Hit}_\text{cap}} \rfloor + 1 }[/math]
  • [math]\displaystyle{ \text{Crit}_\text{proficiency} }[/math] is the plane proficiency critical bonus. Please see Plane Proficiency for more details.
  • [math]\displaystyle{ \text{Const}_\text{contact} }[/math] is the night contact constant from   Night Recons 
     
     
    . It is 0.07 if night contact is triggered, 0 otherwise.

Accuracy Formulas

Below are the common variables used in all accuracy formulas:

  • [math]\displaystyle{ \text{Level} }[/math] is the level of the attacking ship.
  • [math]\displaystyle{ \text{Luck} }[/math] is the luck   of the attacking ship.
  • [math]\displaystyle{ \text{Acc}_\text{equip} }[/math] is the total accuracy   provided by the equipment calculated as [math]\displaystyle{ \text{Acc}_\text{equip base} + \text{Mod}_\text{Impr} \times \sqrt{\bigstar} }[/math]
    • [math]\displaystyle{ \text{Acc}_\text{equip base} }[/math] is the base accuracy   displayed on the equipment.
    • [math]\displaystyle{ \text{Mod}_\text{Impr} }[/math] is the equipment's Improvement modifier for the applicable attack.
    • [math]\displaystyle{ \bigstar }[/math] is the equipment's improvement level.
  • [math]\displaystyle{ \text{Mod}_\text{formation} }[/math] is the formation modifier for the applicable attack. See Combat for more details.
[math]\displaystyle{ \text{Mod}_\text{formation} }[/math]
Formation Day Shelling &
Carrier Attacks
Torpedo Attacks ASW Night Battles
Line Ahead 1.0 1.0 1.0 1.0
Double Line 1.2 0.8 1.2 0.9
Diamond 1.0 0.4 1.0 0.7
Echelon 1.2 0.75 1.2 0.9
Line Abreast 1.2 0.3 1.2 0.8
Vanguard (Top) 0.8 ? ? ?
Vanguard (Bottom) 1.2 ? ? ?
Double Line vs Line Abreast 1.0 N/A 1.0 N/A
Echelon vs Line Ahead
Line Abreast vs Echelon
Combined Fleet Cruising Formation 1 ? ? ? ?
Combined Fleet Cruising Formation 2 1.0 ? ? ?
Combined Fleet Cruising Formation 3 ? ? ? ?
Combined Fleet Cruising Formation 4 1.1 ? ? ?
  • [math]\displaystyle{ \text{Mod}_\text{morale} }[/math] is the morale modifier of the attacking ship. Morale is referring to the value of attacking timing, not the value before entering battle. See Morale and Fatigue for more details.
[math]\displaystyle{ \text{Mod}_\text{morale} }[/math]
Sparkled 1.2
Normal 1.0
Orange 0.8
Red 0.5

Notes:

  • Because of the number of modifiers to accuracy in-game, it is trivial to increase accuracy. Therefore it is more important to prioritize firepower.

Daytime Shelling

This formula applies to both surface shelling and carrier attacks during daytime combat. It does not apply to carrier airstrikes.

[math]\displaystyle{ \text{Accuracy}_\text{shelling} = \biggl\lfloor \left( \left( \text{Acc}_\text{base} + 2\sqrt{\text{Level}} + 1.5\sqrt{\text{Luck}} + \sum_{\text{All Equips}} \text{Acc}_\text{equip} \right) \times \text{Mod}_\text{formation} \times \text{Mod}_\text{morale} + \text{Mod}_\text{fit} \right) \times \text{Mod}_\text{spotting} \times \text{Mod}_\text{AP} \biggr\rfloor }[/math]

  • [math]\displaystyle{ \text{Acc}_\text{base} }[/math] is the base accuracy value of the attack.
    • These values apply for Player as attacker and Enemy as targets. Values for Enemy attacker vs Player target are unclear/unknown, except single vs single = 90.
Fleet type base accuracy values for Player side[1][2]
vs. Enemy
Single Fleet Combined Fleet
Player Single Fleet 90 80
CTF Main 78 77
CTF Escort 45 67
STF Main 45 77
STF Escort 67 67
TCF Main 54 54
TCF Escort 45 67
  • [math]\displaystyle{ \text{Mod}_\text{fit} }[/math] is the Hidden Fit bonuses or penalties when applicable.
  • [math]\displaystyle{ \text{Mod}_\text{spotting} }[/math] is the artillery spotting bonus if applicable. Please see Artillery Spotting for more details.
[math]\displaystyle{ \text{Mod}_\text{spotting} }[/math]
Attack Type Prerequisites Post-cap
Damage
Modifier
Accuracy
Modifier
Hits Notes
Main Suisei Cut-in
(Suisei CI)
    1.3 ? 1 Ise-class Kai Ni 
 
only
Main Zuiun Cut-in
(Zuiun CI)
    1.35 ? 1
Main AP Shell Cut-in
(APCI)
     1.5 1.2 1
Secondary AP Shell Cut-in
(Sec APCI)
     1.3 1.3 1
Secondary Radar Cut-in
(Radar CI)
     1.2 1.5 1
Secondary Cut-in
(Sec CI)
    1.1 1.3 1
Double Attack
(DA)
    1.2 1.1 2
  • [math]\displaystyle{ \text{Mod}_\text{AP} }[/math] is the   AP Shells 
     
     
    accuracy modifier:
[math]\displaystyle{ \text{Mod}_\text{AP} }[/math]
Type Modifier
   1.1
    1.2
    1.25
     1.3

Notes:

  • It is inadvisable to run any of the other setups beyond the most basic Gun+AP. This is because the other setups will interfere with artillery spotting and cost you better attack bonuses.
  • Unlike when calculating damage, the bonus applies to all targets.

Shelling Support

This formula applies to surface shelling and carrier attacks during shelling support.

[math]\displaystyle{ \text{Accuracy}_\text{shelling support} = \biggl\lfloor \left( 64 + 2 \times \sqrt{\text{Level}} + 1.5 \times \sqrt{\text{Luck}} + \sum_{\text{All Equips}} \text{Acc}_\text{equip base} \right) \times \text{Mod}_\text{formation}? \times \text{Mod}_\text{morale} \biggr\rfloor }[/math]

  • [math]\displaystyle{ \text{Acc}_\text{equip base} }[/math] does not include accuracy from improvement level.
  • [math]\displaystyle{ \text{Mod}_\text{formation} }[/math] exists in KanColle Kai, but unclear if it applies to browser KanColle using the Daytime Shelling formation modifier of the main fleet.

Torpedo Attacks

This formula only applies to opening and closing torpedo attacks in day.

[math]\displaystyle{ \text{Accuracy}_\text{torpedo} = \left( 85 + 2 \times \sqrt{\text{Level}} + 1.5 \times \sqrt{\text{Luck}} + \sum_{\text{All Equips}} \text{Acc}_\text{equip} + \left \lfloor{\frac{\text{Attack}_\text{torp}}{5}} \right \rfloor + \text{Mod}_\text{ship} \right) \times \text{Mod}_\text{formation} \times \text{Mod}_\text{morale} }[/math]


  • [math]\displaystyle{ \text{Attack}_\text{torp} }[/math] is the final basic torpedo attack power of the ship. Please see Damage Calculations for details.
    • The figure incorporates any pre-cap and post-cap modifiers and takes into account the attack cap.
    • This means that engagement and damage state play a role in torpedo accuracy.
  • [math]\displaystyle{ \text{Mod}_\text{ship} }[/math] is the innate torpedo accuracy of the ship. Currently, only Abyssal ships have values above [math]\displaystyle{ 0 }[/math].

Aerial Combat

This formula applies to the airstrikes performed during the aerial combat phase and support. Although ASW support functions like an airstrike for damage, it does not use this formula.

[math]\displaystyle{ \text{Accuracy}_\text{airstrike} = 95 }[/math]

Important Notes

  • Airstrike accuracy is a constant and not affected by any outside factors.

Anti-Submarine Warfare

This formula applies to all ASW attacks in the combat phase and support.

[math]\displaystyle{ \text{Accuracy}_\text{ASW} = \left( 80 + 2 \times \sqrt{\text{Level}} + 1.5 \times \sqrt{\text{Luck}} + \sum_{\text{All Equips}} \text{Acc}_\bigstar + 2 \times \sum \text{ASW}_\text{sonar} \right) \times \text{Mod}_\text{formation} \times \text{Mod}_\text{morale} \times \text{Mod}_\text{synergy} }[/math]

  • [math]\displaystyle{ \text{Acc}_\bigstar }[/math] does not include   accuracy stat of the equipment, only the amount from Improvement related to ASW accuracy
  • [math]\displaystyle{ \text{ASW}_\text{sonar} }[/math] is the base ASW stat of any sonars equipped.
  • [math]\displaystyle{ \text{Mod}_\text{synergy} }[/math] is the synergy bonus from equipping certain combinations of ASW equipment.
    • Synergy bonus is either currently bugged or so small it cannot be tested.

Notes:

  • Equipping more sonars is the best way to boost ASW accuracy.

Night Battles

This formula applies to all night battle attacks.

[math]\displaystyle{ \text{Accuracy}_\text{NB} = \bigl( \text{Mod}_\text{contact} \times \left( 69 + \text{Mod}_\text{star shell} \right) + 2 \times \sqrt{\text{Level}} + 1.5 \times \sqrt{\text{Luck}} + \sum_{\text{All Equips}} \text{Acc}_\text{equip} \bigr) \times \text{Mod}_\text{formation} \times \text{Mod}_\text{morale} \times \text{Mod}_\text{special} + \text{Mod}_\text{searchlight} + \text{Mod}_\text{fit} }[/math]

  • [math]\displaystyle{ \text{Mod}_\text{contact} }[/math] is 1.1 if a   Night Recon 
     
     
    triggered, 1.0 otherwise.
  • [math]\displaystyle{ \text{Mod}_\text{star shell} }[/math] is 5.0 if a   Star Shell  is triggered, 0 otherwise.
  • [math]\displaystyle{ \text{Mod}_\text{searchlight} }[/math] is 7.0 if a   Searchlight 
     
    is triggered, 0 otherwise,
  • [math]\displaystyle{ \text{Mod}_\text{fit} }[/math] is the Hidden Fit bonuses or penalties when applicable.
  • [math]\displaystyle{ \text{Mod}_\text{special} }[/math] is the night battle special attack modifier. See Night Battle for more details.
    • Torpedo Cut-in: 1.65,
    • Gun Cut-in: 2.0,
    • Mixed Cut-in: 1.5,
    • Secondary Cut-in: 1.5,
    • Double Attack: 1.1,
    • Other multipliers are unknown.

Land-Based Air Squadron

This formula applies to attacks made by Land-Based Air Squadrons. The accuracy is calculated independently per squadron.

[math]\displaystyle{ \text{Accuracy}_\text{LBAS} = \left( 95 + ( 7 \times {\text{Acc}_\text{equip}}) \right) \times \text{Mod}_\text{morale} + \text{Mod}_\text{proficiency} }[/math] [1]

  • [math]\displaystyle{ \text{Acc}_\text{equip} }[/math] is the accuracy stat of the plane.
  • [math]\displaystyle{ \text{Mod}_\text{morale} }[/math] is the morale modifier of the plane.
    • Normal/Orange morale: 1.0
    • Red morale: 0.8
  • [math]\displaystyle{ \text{Mod}_\text{proficiency} }[/math] is the plane proficiency accuracy bonus. Please see Plane Proficiency for more details.
    • The value is 12 for ❱❱ ranked planes.

Evasion Formulas

Evasion has several caps depending on the calculated base evasion of the ship. Base evasion is calculated as follows:

[math]\displaystyle{ \text{Evasion}_\text{base} = \bigl\lfloor \left( \text{Evasion}_\text{ship} + \sqrt{2\text{Luck}} \right) \times \text{Mod}_\text{formation} \bigr\rfloor }[/math]

  • [math]\displaystyle{ \text{Evasion}_\text{ship} }[/math] is the evasion of the ship including any visible equipment bonuses.
  • [math]\displaystyle{ \text{Mod}_\text{formation} }[/math] is the formation modifier. It varies based on the attack being received. Please see Combat for more details.
    • Currently modifiers for Vanguard are unknown.


The various capped evasion formulas to calculate the final evasion rate is as follows:

  • [math]\displaystyle{ \text{Evasion}_\text{base} \lt 40: \text{Evasion}_\text{cap} = \text{Evasion}_\text{base} }[/math]
  • [math]\displaystyle{ 40 \lt \text{Evasion}_\text{base} \lt 65: \text{Evasion}_\text{cap} = \lfloor 40 + 3\sqrt{\text{Evasion}_\text{base} - 40} \rfloor }[/math]
  • [math]\displaystyle{ \text{Evasion}_\text{base} \gt 65: \text{Evasion}_\text{cap} = \lfloor55 + 2\sqrt{\text{Evasion}_\text{base} - 65}\rfloor }[/math]

Capped evasion is then modified by post-cap modifiers:

[math]\displaystyle{ \text{Evasion %} = \biggl\lfloor \text{Mod}_\text{searchlight} \times \left( \text{Evasion}_\text{cap} + \text{Mod}_\text{sonar} + \text{Mod}_\text{CA} + \text{Mod}_\text{vanguard} - \text{Mod}_\text{fuel} \right) \biggr\rfloor }[/math]

  • [math]\displaystyle{ \text{Mod}_\text{searchlight} }[/math] is the searchlight evasion penalty. It is 0.2 for any ship equipped with a searchlight (even if not triggered) and 1.0 otherwise.
  • [math]\displaystyle{ \text{Mod}_\text{sonar} }[/math] is the sonar improvement modifier that only applies to opening and closing torpedo attacks. It is 0 otherwise.
    • [math]\displaystyle{ \text{Mod}_\text{sonar} = \sum_{\text{All Sonars}} 1.5\sqrt{\bigstar} }[/math]
  • [math]\displaystyle{ \text{Mod}_\text{CA} }[/math] is the heavy/aviation cruiser night battle evasion bonus. It is 5 for heavy/aviation cruisers and 0 otherwise.
  • [math]\displaystyle{ \text{Mod}_\text{vanguard} }[/math] is the Vanguard evasion bonus. This is different from the formation modifier that gets taken into account for base evasion. Bonuses are:
    • For ships at the top (slots 1-2 or 1-3): Non-destroyers get a 5% bonus. Destroyers get a 20% bonus.
    • For the rest of the ships at the bottom (slots 3-5 or 4-7): Non-destroyers get a 20% bonus. Destroyers get a 40% bonus.
  • [math]\displaystyle{ \text{Mod}_\text{fuel} }[/math] is the remaining fuel penalty.
    • [math]\displaystyle{ \text{Mod}_\text{fuel} = 75 - \text{Fuel} }[/math]
    • If fuel is above 75%, the penalty is 0.
    • The penalty is an integer and not a percentage.
Remaining Fuel Penalty
Battle #[1] Remaining Fuel Penalty
2nd Battle 80% 0
3rd Battle 60% 15
4th Battle 40% 35
5th Battle 20% 55
6th+ Battle 0% 75
  1. This only takes into account normal day battles. Special nodes have different resource consumption.

Notes:

  • The speed of the fleet is supposed to play a role in evasion. Currently, said increase is either nonexistent or too small to test.
  • Using AO equipped with   Underway Replenishment  is a way to medigate fuel penalties.

Special Cases

PT Imps

PT Imps were introduced during the Summer 2017 Event.

Anti-PT boat
Unlike most standard Abyssals, "PT boats" (PT Imp Pack  & Schnellboot Imp Pack ) are "very small and fast".
  • All ship types suffer a severe   accuracy and   firepower penalty against PT boats.
  • Attacking them with larger guns is not very effective, smaller guns being recommended instead.
  • Support Expeditions are not affect by any of the following[1].
Attack formula against PT boats
The Attack formula against PT boats:[2][3]
Jet Assault & Airstrike
  • [math]\displaystyle{ \text{Damage}_\text{PT}= \text{Atk}_\text{post-cap} \times \text{Rand} [0.5 ; 0.8] }[/math]


LBAS[4]
  • [math]\displaystyle{ \text{Damage}_\text{PT}= \text{Atk}_\text{post-cap} \times \text{Rand} [0.4 ; 0.7] }[/math]


Shelling
  • [math]\displaystyle{ \text{Damage}_\text{PT}= ( 0.3 \times \text{Atk}_\text{post-cap} + \sqrt{\text{Atk}_\text{post-cap}} + 10 ) \times \prod^{All Equipment}{\text{Mod}_\text{EquipmentAtk}} }[/math]


Opening & Closing Torpedo Salvos
  • [math]\displaystyle{ \text{Damage}_\text{PT}= 0.3 \times \text{Atk}_\text{post-cap} + \sqrt{\text{Atk}_\text{post-cap}} + 10 }[/math]


Night Battle
  • Night Battle data are unclear yet.


With
  • [math]\displaystyle{ \text{Atk}_\text{post-cap} }[/math] the post cap attack power defined here,
  • [math]\displaystyle{ \text{Mod}_\text{EquipmentAtk} }[/math] the bonuses given by equipment, described below.
Accuracy formula against PT boats
The Accuracy formula against PT boats:[5][6][7][8]
[math]\displaystyle{ \text{Hit Rate}_\text{vs.PT} \text{%} = \Big\lfloor ( 0.3 \times \text{Accuracy}_\text{Atk} + \sqrt{\text{Accuracy}_\text{Atk}} + 15 ) \times 1.2 \times \text{Mod}_\text{Ship} \times \Big( \prod^{All Equipment}{\text{Mod}_\text{EquipmentAcc}} \Big) \times \text{Mod}_\text{Night} \Big\rfloor - \text{EVA}_\text{PT} + 1 }[/math]
With
  • [math]\displaystyle{ \text{Acc}_\text{Atk} }[/math] the standard accuracy described here
    • PT boats are "DDs" in the game, so the [math]\displaystyle{ \text{Mod}_\text{formation} }[/math] for vanguard is 1.1 during shelling, and 1.2 during the torpedo phase.
    • Historical accuracy bonuses during Events are included in the Standard Accuracy Term, i.e. it is affected by the [math]\displaystyle{ \text{Mod}_\text{PT} }[/math] modifier.
  • [math]\displaystyle{ \text{EVA}_\text{PT} }[/math] the PT estimated evasion   described bellow,
PT boats stats
Type Luck   Eva   [math]\displaystyle{ \text{EVA}_\text{PT} }[/math]
Line Ahead  Echelon  Line Abreast 
PT Imp Pack  ? ? 81? 87? ?
PT Imp Pack II  60 220 80 87 85
PT Imp Pack III  60 250 82 89 88
PT Imp Pack IV  ? ? ? 84? ?
Schnellboot Imp Pack  ? ? ? ? ?
Schnellboot Imp Pack II  ? ? ? ? ?
Schnellboot Imp Pack Elite  ? ? ? ? ?


The main Accuracy modifiers are
  • [math]\displaystyle{ \text{Mod}_\text{Amagiri} }[/math] being include in [math]\displaystyle{ \text{Acc}_\text{Atk} }[/math]:
  • [math]\displaystyle{ \text{Mod}_\text{Ship} }[/math] the bonus given by ship types, described below,
  • [math]\displaystyle{ \text{Mod}_\text{EquipmentAcc} }[/math] the bonuses given by equipment, described below,
  • [math]\displaystyle{ \text{Mod}_\text{Night} }[/math] being 0.7 during night battle, 1 during day battle.


Amagiri Kai Ni/D 
 
has the ability to prioritize focusing on attacking PT imps with significantly increased accuracy if any are present.

  • DD placed in the composition slots above and below her will gain a noticeable accuracy boost and will prioritize attacking PT boats if any are present.
  • The PT boat targeting rate is 100% for all affected ships [9].

During Events, some special bonuses may be added, with "historical" ships and equipment gaining some accuracy bonuses[10].

Ship Type [math]\displaystyle{ \text{Mod}_\text{Ship} }[/math]
DD & DE 1.0
CL, CLT, & CT 0.82
All other types 0.7
Equipment [math]\displaystyle{ \text{Mod}_\text{EquipmentAcc} }[/math] [math]\displaystyle{ \text{Mod}_\text{EquipmentAtk} }[/math]
1st equipped 2nd equipped 1st equipped 2nd equipped
  Small Small Caliber Main Guns[11] 1.3 1.15 1.5 2.11.5×1.4
  Sec Secondary Guns[12] 1.55 1 1.3
  Anti-Aircraft Guns 1.45 1.35 1.2 1.441.2×1.2
  Skilled Lookouts 
 
1.75 1 1.1
 Armed Soukoutei (Armored Boat Class)  1.45 1.3 1.2 1.1
Armed Daihatsu  1.45 1.3 1.2 1.1
  Ka-Tsu Tanks 
 
[13][14]
1 1.3 1 1.1
 Bomber  Seaplane Bombers & Seaplane Fighters 1.5 1 1.2
    Dive Bombers & Jets 
 
1.375 1.2 1.4 1.821.4×1.3
All other equipment 1 1
Notes
  • It is recommended to use anti-PT setups on DDs only, such setups compromising overall combat effectiveness.
  • Having a Reinforcement Expansion is important because it can save a ship slot by containing a machine gun or skilled lookouts.
  • Combining equipment is recommended to see significant boosts to accuracy.
  • The   Ka-Tsu Tanks 
     
    bonus does not stack with the   Armed Boats 
     
    ones.
  • Using other setups improving accuracy is also advisable:
References:
[edit]