Tank Armor is a hidden parameter of most armored vehicles, allowing to potentially deflect certain kinds of incoming fire. Deflected shots do not cause any damage and penetrating shots deal their full damage.
Only certain types of shells can be deflected: all armour piercing damage sources, 20mm, 30mm, 40mm, and R.P.G. Shells. If a weapon or ammo type's description specify it can penetrate armour that means it has a chance to be deflected, ironically. All other types of weapons will always cause damage, but usually less than a penetrating armour-piercing shell.
Vehicles with higher tank armor have a higher chance to deflect incoming fire. Every penetrating shot reduces the vehicle's Tank Armor value (by the damage amount), making the next shots more likely to penetrate. Different ammo types have different chances to penetrate Tank Armor.
Certain shells have bonuses to penetration chance when hitting Tank Armor (mentionned in their description):
- Closer shots have a higher chance to penetrate.
- More direct shots (orthogonal) have a higher chance to penetrate the side and rear armour.
Deflected shots make a "pssht" sound and produce sparks.
The state of a vehicle's tank armor is reflected visually by wear and tear.
- P: Total penetration chance (%)
- P0: Base penetration chance (%) (Hard coded value unique to each armored vehicle)
- S: Armour Stripped (%)
- S0: Maximum Armour Stripped (%) (Most vehicles cannot have all their armour removed, there's always a small amount of armour that remains. Hard coded value unique to each armored vehicle)
- M: Ammo Type Multiplier (Innate characteristic to each ammo)
- R: Range Bonus (Pen Bonus multiplier)
- A: Angle Bonus (Pen Bonus multiplier for Rear/Side shots only)
If the ammo used doesn't have Pen Bonuses, they are equal to 1 for the following equation.
P = min(S0,max(P0,S))*M*R*A
The Ironhide has a base penetration chance of 27%, the A.T.R.P.G. Indirect Shell has an Ammo Type Multiplier of 2.5 and doesn't use Penetration Bonuses. So an Ironhide with intact tank armor hit by a Bonesaw will have a 67.5% penetration chance (0.27*2.5=0.675). If its tank armor is down to 50%, the penetration chance becomes 100% (0.5*2.5=1.25).
68mm AT shells have an Ammo Type Multiplier of 1.5. If an intact Ironhide is shot on its front there's no Angle Bonus and if the shot came from more than 40m there's no Range Bonus either, so the penetration chance is 40.5% (0.27*1.5*1*1=0.405). The ironhide's armour can't go below 33% so its Maximum Armour Stripped value is 66%, so if its armor is depleted entirely the penetration chance becomes 99% (0.66*1.5*1*1=0.99).
Vehicles with Tank Armour cannot be packaged if their Tank Armor isn't fully intact, the vehicle's Tank Armor must be repaired at a Garage first. Trying to package a vehicle can be an easy way to verify its Tank Armor is intact.
Other armor mechanics
"Light" armored vehicles are very resistant to the Light Kinetic damage type. Every Light Kinetic weapon and ammo deals only 1 point of damage to them.
"Heavy" armored vehicles are very resistant to the Light Kinetic,Heavy Kinetic, and Shrapnel damage types. Every Light Kinetic, Heavy Kinetic, and Shrapnel weapon and ammo deals only 1 point of damage to them. This means a Mortar Shrapnel Shell, a 12.7mm machine gun bullet and a 8mm pistol bullet all deal the same damage to that vehicle.
Light Armor Vehicles:
Heavy Armor Vehicles: