Thanks to Takru for sending me this, Sub_Octavian has shared a nice article about how shell dispersion works on Reddit. For those who don’t use Reddit, I’ve decided to share it here so all of you can read it.
Source: World of Warships Reddit
Okay, so after a bunch of questions about the accuracy and aiming, the cryptic vertical dispersion and the mysterious sigma, I realized this topic deserves additional clarification. And I even promised to write a little article in one of Q&As (uh-oh!).
I’m publishing this explanation here on Reddit because this is (please don’t laugh) hardcore information, and not much use to wide audience. I, for example, am a simple man: I see the target, I shoot – and usually the results are nice. That’s because shooting is designed to be more “intuitive” than “calculated”. Practice makes WoWs shooting perfect, sitting with calculator – hardly. However, I hope this post will be useful to those brave sailors who seek profound knowledge.
Info is actual for v0.6.6. I will not update it, but any meaningful changes (if there are any), will be added to patch notes, just like with other game components.
Urgh, let’s get to the point, finally.
Each time you fire a salvo, there is dispersion area being built. It is influenced and NOT influenced by many things! What does matter?
Dispersion parameters. Basically, dispersion of a given salvo has the following parameters: horizontal and vertical dispersion (together, they determine dispersion ellipse), and sigma count. Sigma count basically determines the density of a salvo towards ellipse center.
Vertical and horizontal dispersion always grow with range.
Dispersion ellipse is initially projected on your aiming plane, not on water. Shells are set to pass through it – see the picture with initial ellipse and real ellipse. In game that means that ships with better ballistics will have longer real ellipses – flatter shell trajectories result in real ellipse stretching more. MAD PAINT SKILLZ ENGAGED:
(in this example I assume you are targeting exactly at water line – of course you can aim higher or lower, changing your initial ellipse position on the plane and changing real ellipse as a result.
There are three stances of dispersion ellipse parameters (well, there are more technically, but only three are used). Between them, dispersion changes are lineal. The stances are: minimal dispersion (closest shooting distance), close dispersion (set around 4 km) and maximum dispersion. You can see horizontal dispersion for maximum range in Port, by the way.
For each stance, there are two parameters: horizontal dispersion and relation between horizontal and vertical dispersion. Relation may be used in balancing. For example Fuso is better at long range shooting than New Mexico – check out my super-10-salvos-per-second-shooting:
Target lock is a must There is absolutely no point in shooting without target lock, if you are able to acquire it. Apart from adding aiming plane to locked target, it greatly improves your horizontal dispersion (like, twice lower!).
By the way, aiming plane is needed due to line of sight issues – e.g. you may be targeting ship superstructure, but without adjusted aim the game may as well think you are targeting the mountain behind:
So aiming plane (target lock) is your friend and allows you to shoot with black trajectories (good), not with red (bad):
The dispersion debuff without target lock is added primarily to protect “anti-dispersion” camo and related upgrades / captain skills from being bypassed by mods.
Camo / concealment upgrade debuffs and upgrade buffs are applied to horizontal dispersion at maximum range. The effects multiply, so shooting at camo target (x1.04) with Aiming mod 1 (x0.93) results in x0,96 to maximum range horizontal dispersion. Gameplay-wise that means these effects are growing with range and have almost no influence on CQC.
Your sigma count matters – while not influencing dispersion ellipse in any way, it influences the density if your salvos. Shells are being placed by Gaussian distribution, and sigma count affects it. The parameter may be tweaked per ship, but it is not very diverse. The base is 2.0. The more = the better. It is used in balancing. For example, Fuso has huge salvos, so it is set with 1.5, and BBs tend to have lower sigma count in general. T9-10 cruisers were systematically and gently buffed lately by giving them 2.05.
Now, just to be sure, these things DO NOT influence your dispersion in any way:
- Your maneuver and speed.
- Quantity of turrets firing a salvo.
- Any game modifications.
Yes, this mechanics is complex. It was a challenge to design and implement, it is a challenge to describe and explain, but mostly, you don’t need to bother about it. It is here, and it works, allowing you to aim your guns and have fun. I hope I was able to highlight several nuances that matter.