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Gameplay: Armor Penetration Mechanics

Basic principles of armor penetration in World of Tanks Blitz

  • Any shell in the game is a material point of zero size, which means that it can fly through gaps.
  • Armor-Piercing (AP) and Armor-Piercing Composite Rigid (APCR) shells can penetrate destructible obstacles (fences, boxes, etc.) and inflict damage to tanks behind them. High-Explosive (HE) and High-Explosive Anti-Tank (HEAT) shells explode when colliding with destructible objects and therefore do not fly further.
  • The reduction of armor penetration capability after encountering an obstacle depends on the object’s size and strength. For example, a wooden box will not reduce armor penetration as much as a car. Regardless of penetration capability, the amount of damage that the shell can inflict does not decrease.
  • It is possible to shoot through several obstacles at once, decreasing armor penetration of the shell as it passes through each object.
  • It is also possible for a shell to ricochet from the original target to hit another tank and inflict damage on it. A shell can ricochet only once, after that it either deals damage (if armor is penetrated) or disappears. You cannot shoot through several tanks at once.
  • Starting with Update 6.0, the armor penetration spread is ± 5% of the mean value and is indicated in the characteristics of the gun. The damage spread is ± 25% of the mean value and is also indicated in the characteristics of the gun.
  • Damage to tank modules is an implicit value, depending to a certain extent on the ammo caliber.
  • External modules have their own armor. When this armor is pierced, the armor penetration index of the shell is reduced by the module armor value. For external modules, normalization is not calculated. There is no ricochet from external modules.
  • The ricochet angle of a shell is calculated from the surface normal and is 70 degrees for AP and APCR shells, HEAT shells never ricochet.
  • HE and HEAT shells do not ricochet.
  • After ricocheting, the shell loses 25% of its armor penetration capability.
  • After a ricochet, the shell changes its path accordingly. If the shell scores a second ricochet, it immediately disappears.
  • Normalization (the angle to which the shell converges if there was no ricochet) is 5 degrees for AP shells and 2 degrees for APCR shells. There is no normalization for HE or HEAT shells.
  • Normalization does not affect the path of the shell, but only changes the impact angle for further calculations.
  • The two-caliber rule: if the shell caliber is more than two times the armor thickness (without taking into account the impact angle), the angle of normalization will increase according to the following rule: resulting normalization = the shell normalization angle * 1.4 * shell caliber / 2 * armor thickness at point of impact.
  • The three-caliber rule, for all types of shell except for HEAT and HE: if the shell caliber is more than three times the armor thickness (without taking into account the impact angle), there is no ricochet. Normalization is calculated immediately and the armor penetration check begins.
  • The ten-caliber rule: after penetrating the armor and when causing damage, the shell can travel into the hull for a distance of up to ten shell calibers (but not less than 0.5 m).
  • Rules for HEAT shells:
    • A HEAT shell can not ricochet
    • After the point of penetration, the shell begins to lose armor penetration at the following rate: 5% of the remaining armor penetration per 10 cm of shell travel (50% per 1 meter of screen-to-armor clearance)
    • Tracks act as a screen for HEAT shells.


  1. The shell hits a certain point of the tank.
  2. The distance to the impact point is calculated.
  3. The armor penetration capability of the shell is calculated taking into account the randomization factor of ± 5% and penetration degradation over distance.
  4. Statistics at the point of impact are checked.
    • If the external module is hit, then the module armor thickness value is taken away from the shell armor penetration capability. The path of the shell is drawn until the next impact (if the shell still has armor penetration capability). (Return to item 4.)
    • If the shell reaches the screen or main armor of the tank, the checks continue.
  5. The possibility of ricochet is checked, accounting for the three-caliber rule.
    • If this is a second ricochet, the shell disappears.
    • If this is the first ricochet, then 25% armor penetration capability is lost for AP and APCR shells.
  6. If there is no ricochet, the checks in item 7 begin.
  7. The two-caliber rule is checked. If it works, then basic normalization is replaced by one calculated according to the following rule: resulting normalization = the shell normalization angle * 1.4 * the shell caliber / 2 * armor thickness at impact..
  8. Thickness of the armor is calculated at the point of impact.
  9. The armor penetration of the shell is decreased by the value of the penetrated armor thickness.
  10. If the remaining armor penetration of the shell is greater than zero, a penetration sticker is drawn at the point of impact, and the type of armor is checked.
    • In the case of screen armor, the shell continues further. (Return to item 4.)
    • In the case of main armor, the following calculations in item 11 begin.
  11. The damage to a tank's HP is calculated by randomly selecting values in the range of ± 25% of the shell's specified damage.
  12. The tank takes damage and the shell travels further inside the vehicle.
  13. The ten-caliber rule applies. The shell will cease to exist, having travelled a distance of 10 calibers (but not less than 0.5 meters for small-caliber weapons).
  14. If the shell encounters a module or a crewmember on its way, it checks whether the chance to damage succeeded. (Chance to damage: track—100%, the engine—45%, the fuel tanks—45%, the triplex—45%, the turret traverse mechanism—45%, the gun—33%, the ammo rack—27%, the crew member—33%). If the module or the crew member "dodged", then the shell ceases to exist. If damage has been inflicted, the shell continues to travel according to the above rules.

Common Cases of Weird Non-Penetrations or Hits

Most cases that cause questions among players are due to the fact that the shell penetrates the external module or screen, but does not penetrate the tank's main armor or does not reach it. Several examples:

  • The shell hits the track and goes into the ground but with the voiceover: "Enemy is hit!"
  • The shell hits a "dodging" gun with the voiceover: "We didn't penetrate their armor!" If the gun is damaged you will hear the standard phrase: "Enemy is hit!"
    It is not uncommon for a HE shell to hit the tip of the gun and explode there. If the gun is long, then the fragmentation radius will not be enough to inflict any damage to the hull.

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