In World of Warships you have a choice between armor-piercing(AP) shells and high-explosive(HE) shells to inflict damage via your main guns on your ship. Each shell has its own use and determining which shell to use is important for dealing the maximum amount of damage possible with each salvo you fire at an enemy ship. Fundamentally an AP shell is meant to penetrate a well protected area of a warship and then detonate inside the ship to inflict a massive amount of damage. If an AP shell has to much penetration it runs the risk of over penetrating its target and will do minimal damage. HE shells on the other hand are not meant to penetrate a ship(although they still can) and rather are used to deal damage against poorly armored areas of ships, to cause fires, and to damage modules. Factoring in these strengths/weaknesses of each shell along with what enemy ship you are firing at, the range it is at, and the speed it is travelling is key to finding out what shell is best for that specific situation.
Keywords and Damage Mechanics
To cause damage in World of Warships a shell needs to penetrate a layer of armor on an enemy warship and the shell needs to detonate inside of the ship(or within HE’s blast radius). Each shell has a damage value, penetration value, detonator threshold, and fuse length assigned to it that will determine how much and if damage occurs against an enemy ship. Each ship is divided into four different sections each with its own set of hit points(all four in total exceed the maximum hit points of a ship) and an additional section for the citadel. Each section, excluding the citadel, has a limited amount of hit points that limits the amount of damage a specific area can receive before not taking any direct HP damage(fires and over-penetrations will still cause damage). The citadel section has the same amount of hit points as a ship. Each ship’s sections consist of the bow, midsection, stern, superstructure, and citadel area.
Damage is calculated in World of Warships based on the amount of damage a section of a ship has taken, the damage of the shell, and where/if it penetrates the armor. Each section of a ship starts off at 100% HP and appears visually to have taken no damage. Each section has two thresholds and as a section takes more damage it will in return reduce the amount of damage each shell does to it as the HP becomes low. Initially a section will receive normal damage(visually it appears undamaged) and shells will cause (shell damage x 0.33) for penetrations. After the first threshold is reached(it is different for each ship/section) the section of the ship will change visually and become black/heavily damaged. At this point shells no longer do (shell damage x 0.33) and instead the damage is halved to (shell damage x 0.165). Once the final threshold is reached the section will stop taking damage(visually it does not change in appearance) and the only way to cause damage is with fires and over-penetrations.
There are some exceptions to causing damage to ships and how each section of the ship influences damage taken.
- Over-penetration will always deal (shell damage x 0.1) regardless of which threshold a section is on
- Citadel hits will always deal (shell damage x 1.0) even if a section has run out of HP since the citadel is not tied to a specific section
- If the midsection section(amidships) reaches the final threshold(no remaining HP) all other sections will take damage as if they reached the first threshold (shell damage x 0.165) instead of (shell damage x 0.33)
- Fire, flooding, over-penetration, and citadel damage does not reduce a section’s HP(bow,stern,midsection,superstructure) and only affects the ship’s HP pool.
- Sections with no remaining HP will still take flooding and fire damage
Damage Value: Each shell has a specific damage value assigned to it and unlike World of Tanks in World of Warships there is no +-25% random damage value assigned to each shell. A shell’s damage is based on whether it penetrates a ship, where it penetrates a ship, and the damage value it has.
Penetration Value: A shell’s penetration value in World of Warships is no affected by a random number generator(+-25%) like in World of Tanks. Instead each shell has a certain penetration value(also referred to as a projectile’s krupp) that is based on its velocity and mass. This penetration value does not change but is influenced by the distance a shell has to travel and the further a shell has to travel the more penetration it will lose. A shell that hits angled armor also will need to penetrate more armor to penetration completely and shells have a chance of bouncing/ricocheting if hitting a heavily angled piece of armor.
Detonator Threshold: The detonator threshold on a shell refers to the amount of armor needed to activate the fuse on the shell. For example, a shell with a detonator threshold of 68 will need to encounter enough armor(presumably 68mm of it) to cause the fuse to be activated. Most high-explosive shells have a detonator threshold of 2 while armor-piercing rounds typically are 30 and above.
Fuse Length: Once the detonator threshold is reached the fuse is activated. Armor-piercing rounds have a longer fuse time than high-explosive and require more time before detonating. A shell must detonate inside the ship to cause damage(or within a high-explosive shell’s blast radius). High-explosive shells typically explode very quickly(0.001 fuse value) while armor-piercing shells take slightly longer to explode(0.033 fuse value) which can cause armor-piercing shells to over-penetrate a target and cause minimal damage.
Types of Shells in World of Warships
Armor-piercing shells require the shell to penetrate the enemy ship’s armor to cause any amount of damage with the shell. Armor-piercing shells do more damage per shell than high-explosive shells and have more penetration than high-explosive shells. Unlike high-explosive shells armor-piercing shells do not have a chance to cause fires to enemy ships. Armor-piercing shells are great for dealing with enemies you know you can penetrate since they cause reliable damage and lead to more citadel/magazine/propulsion critical hits. Armor-piercing shells have a higher detonator threshold and also a longer delay(fuse) before it will explode. This leads to armor-piercing shells being better at damaging heavily armored ships since they can penetrate the thicker armor that high-explosive shells cannot and in the process cause more damage per shell. Due to the high detonator threshold and longer fuse length armor-piercing shells are capable of traveling through water(to a certain extent) while still having enough penetration to punch through a ship’s armor and enough fuse length to detonate inside the ship.
+Damage Per Shell (Who doesn’t like more damage not tied to RNG?)
+Penetration (Citadel areas are well protected and more penetration opens up more citadel chances)
+Water Penetration (Weaker armor is located beneath the waterline on almost all ships)
-Detonator Threshold (Requires thicker armor to detonate shell resulting in more over-penetrations)
-Fuse Length (Longer fuse length leads to more over-penetrations)
-Fire Chance (No chance to cause fires)
High-explosive shells do less damage per shell when compared against armor-piercing shells but do come with their own advantage. High-explosive shells do not need to penetrate a ship’s armor to cause damage but landing a hit against thick armor will reduce the damage you inflict. Unlike armor-piercing shells high-explosive shells have a chance to ignite fires that will cause damage over time to an enemy ship. A ship can have up to four fires at any one time and the damage adds up quickly along with the upfront damage from the shell itself if no repair kit can be used. High-explosive shells have a lower detonator threshold compared to armor-piercing shells and also a shorter delay(fuse) before it explodes. This makes high-explosive shells better at damaging poorly armored ships since they will not over-penetrate and also result in the inability to travel through water to cause damage since the shell will detonate to early. Unlike armor-piercing shells high-explosive shells also have an explosion size(blast radius) value that varies based upon the size of the shell, this explosion will help inflict damage to surrounding modules/cause fires but will not cause HP damage directly.
+Fire Chance (Chance to cause up to 4 fires that cause damage over time without you needing to continue firing shells)
+Detonator Threshold (Does not Require thicker armor to detonate shell resulting in less over-penetrations)
+Fuse Length (Shorter fuse length means you won’t over-penetrate ships)
-Water Penetration (Lower detonator threshold prevents HE from passing through much if any water)
-Penetration (Less penetration prevents high-explosive shells from penetrating many ships, primarily cruisers and battleships)
-Damage Per Shell (Less guaranteed damage that isn’t RNG dependent(fires))
Shell Type Guide Based on Ship Class
Below is a simple guideline that helps you determine the type of shell to use on an enemy warship. It factors into what ship you are in, the enemy ship, and whether it is a lower tier, the same tier, or a higher tier ship compared to your warship.
Playing as a Destroyer
Destroyers are typically the smallest warship in the match when it comes to the size of the ship but also when it comes to the main guns on the ship(excluding torpedoes). This forces you into using HE shells for the majority of situations since you do not have the guns to reliably damage battleships regardless of their tier with AP shells. Against other destroyers and carrier vessels you are best using HE shells against them since they do not have a ton of armor and HE shells will inflict a lot of damage regardless of if they are above or below your tier ship. Against other destroyers at close range however you can gamble with AP shells but since destroyers do not have citadels it is a moot point. High-explosive shells will cause more module damage, cause fires, and reliable damage while even if you penetrate with AP you will most likely be behind in total damage done.
Cruisers are the one class where destroyers have a viable decision as to whether to use HE or AP shells. At long range and/or against a higher tier cruiser it is best to use HE shells since AP shells will either have a low chance of penetrating the strongest armor on the cruiser or a very low chance of hitting an important area of the ship at long range. At closer ranges(under 6 km) against cruisers the same tier or lower than your destroyer AP rounds can usually penetrate their citadel’s armor. HE rounds are still not a terrible option since they can cause fires and damage an enemy warship’s gun/torpedo launchers. The benefit of using AP over HE in this situation is that with AP you can cause more damage if you can land hits on the citadel reliably and more importantly increase your chance of knocking out the enemy warship’s propulsion system(thus making it easier for you to hit them with torpedoes).
Playing as a Cruiser
Cruisers are the most difficult class of ship to play when it comes to deciding what type of shell to use against other cruisers and battleships. Against destroyers and carrier vessels, regardless of their tier, you should use HE shells the majority of the time since they are poorly armored. Due to this your HE shells will not only cause a lot of damage per hit but they also will cause fires that will inflict additional damage. The only situation to use AP is when you are at closer ranges(under 8km) where you have a very good shot at the citadel on a carrier vessel. In this case your AP rounds can deal a massive amount of damage if they hit the citadel and important areas on the enemy ship. Outside of this close range encounter HE shells are the more reliable and better option against destroyers and carrier vessels.
Against other cruisers you should use AP shells under 10 km unless you are facing a heavily armored cruiser and you are a lower tier. Enemy cruisers have enough armor to prevent you from over penetrating the ship and citadel hits will take out an enemy cruiser faster than trying to rely on fires and HE damage. If at under 10 km you are not able to get a clear shot on their citadel then swapping AP out for HE is still a viable choice, but if you have clear shots on their side AP will deal a knockout blow faster in most cases. For distances over 10 km high-explosive shells will cause more damage, damage more modules, and cause fires since you are unable to pinpoint your shells at specific areas. AP shells still have a good chance at penetrating citadel areas at long range but are less reliable due to the longer ranges and enemy cruisers being able to dodge.
When facing a battleship in a cruiser your shell type comes down to what tier the enemy battleship is, since generally the higher tier it is the more difficult it will be for you to penetrate its citadel. Against battleships that are the same tier or lower than you AP shells are the best option since you will be able to penetrate their citadel armor on a somewhat reliable basis at most ranges. Like other classes you should use HE shells against battleships at or below your tier near your maximum range since your shells have a lower chance to hit vital areas. Against higher tier battleships you should rely more on HE shells since your chances of penetrating the strong citadel armor is reduced being a weaker ship. However, at closer ranges you can throw in a few salvos of AP shells to test if your AP shells are capable of penetrating the battleship’s citadel armor. If you are doing no damage or minimum damage then change back to HE shells since you simply do not have enough penetration. However, there is a chance that you are capable of penetrating with AP against a higher tier battleship and if you can then you will do a surprising amount of damage with your quick reloading guns. Usually if a battleship is exposing their side armor to you without additional angling as a cruiser you can penetrate and cause more damage with AP than HE at under 10 km.
Playing as a Battleship
Battleships being the behemoths on the sea have the most firepower but with it need to be careful with where they throw their massive shells since they have very long reload times to go with the massive damage potential. Battleships have a very long maximum range when compared to other classes and unlike other classes where HE shells can sometimes be useful near their maximum ranges battleships are better off with AP shells. Going against ships lower in tier or higher in tier than your own battleship usually doesn’t change whether or not you will not penetrate their armor. Against enemy battleships and cruisers you will only want to use AP shells since you are capable of penetrating their armor without over penetrating at any range(and thus AP will result in more damage than HE). With AP your battleship is capable of destroying other battleships and cruisers with 1-2 well placed salvos if you can hit the citadel.
Against carrier vessels you will want to use HE shells since carrier vessels do not have a ton of armor protecting the ship and HE shells have a high chance of causing fires. When a carrier vessel is on fire it cannot launch ships and this you take away their primary method of dealing damage. If you are already loaded with AP then it is better to stick with firing your AP salvo rather than switch to HE shells. Make sure you always try to hit the citadel area, which on carrier vessels is usually located in the middle of the ship but slightly more towards the rear compared to other classes.
Enemy destroyers being very poorly armored run the risk of being over penetrated by a battleship AP shell. At the same time AP shells from battleships will still often take out an enemy destroyer(regardless of tier) quick since it does not take many direct hits to obliterate a tiny destroyer with a battleship shell. My rule of thumb is that if I see a destroyer and I know I will use my next salvo on it, then I will switch from AP over to HE after I fire that loaded AP salvo. However, if AP shells are already reloaded or are loaded then simply fire AP at a destroyer since you still have a high chance at dealing a massive amount of damage to that destroyer. HE shells are simply a little more reliable due to destroyers being very poorly armored and also being very difficult to hit with their high speeds.
By now you should know a rough sense of when you should use an AP shell or HE shell against an enemy ship. Learning what type of shells works best against a specific enemy ship comes down to range, your weapon capabilities, and what class enemy ship you are engaging. This guide provides you a general guideline but the best way to learn is to experiment on your own and figure out the best tactic that fits you.