Damage

Damage is what a round does once it is through the armour. Getting through is only half the job: what the round does inside decides whether the target keeps fighting.

Spare penetration

How much damage a round does to the part it hits depends on how much penetration it had to spare.

If you can choose, shoot the plate your round beats easily, not the one it barely beats.

A hit that fails to penetrate can still do 35% of its damage. This only applies to a part that can be damaged, such as a module or an add-on panel. The round needs penetration at least equal to the armour of the part. Engines, fuel tanks, transmissions, batteries and turret rings are easier: about 29% of their armour is enough.

Spall

Spall is the spray of fragments that comes off the inside of a plate when a round gets through it.

• Most tank shells throw the same number of fragments. The count tops out at a 2 kg shell.
• A plate that is very thin compared with the round, under 10% of its penetration, throws fewer.
• Each fragment can go through up to 10 mm of armour, and less towards the edge of the spray.

A spall liner is an inner lining that catches fragments. It counts as six times its real thickness against spall, and a round that strikes a liner makes no spall at all.

HEAT jets

A HEAT jet fades once it is inside, losing 20% of its penetration for every metre after the first 0.7 m. Every module and crew member along its line is hit.

Modules take the same damage as from any other penetrating round, with the same 35% floor. Crew damage scales with the penetration the jet has left, with no floor.

Explosions

An explosion does damage twice: once from fragments and once from the pressure wave.

A blast can't hurt a vehicle part whose armour is thicker than the blast's own penetration. That is why high explosive does little to a tank's hull.