Penetration Mechanics Explained

Armour is three separate questions: did it cover the hit, how worn was it, and was the round strong enough when it arrived? Answer them in that order. A class badge alone cannot tell you whether a shot was protected.

This guide owns the tactical reading of coverage, durability and wear. For the exact curves, formulas and current simulator assumptions, use the Damage Model.

Coverage comes first

Gear only changes a shot when its protection geometry reaches the zone that was hit from the shot’s facing. If it does not, the round meets bare flesh and the gear loses no durability.

Body armour

Vests protect named zones, and some of those zones only within a wedge. Front and rear share the same two-sided wedge test; flank is the facing that can change the answer. Arms and legs are often outside the vest, but the selected piece — not a generic rule — decides.

Helmet and face shield

The helmet shell, a shield filling its holes, and uncovered head are separate readings. Helmet and shield protection never stack on one hit; one piece covers the point or it does not.

In the simulator, use the Body and Head views rather than inferring coverage from an item’s headline class. The selected zone’s Reading names the gear that actually intercepted it and how much of that zone it reaches.

Durability changes the matchup

Durability is not only a countdown until armour breaks. Wear lowers the class the piece is effectively rating at, so a matchup can move from mostly stopped to mostly through before the durability display reaches zero. The exact shape belongs to each piece’s curve; there is no safe universal conversion table.

Range and wear move the matchup in opposite directions. When range reduces the round’s penetration, the armour-minus-penetration gap grows against the shooter. When wear lowers the effective class, that gap shrinks.

Fresh

Plan against the zone class the piece actually carries. Do not substitute the item-card badge for a zone reading.

Worn

Expect the effective class to fall during a string of covered hits. Re-check the shot ladder instead of treating every round as the first.

Broken

Penetration is unconditional. The hit still follows the covered, penetrating damage path, so it can differ from the same shot on naked flesh.

Every covered hit spends durability whether the round is stopped or goes through. How much it spends is part of the shot arithmetic; inspect it in the single-shot calculator instead of relying on a fixed rule of thumb.

Turn the reading into a decision

1Check the zoneIf the chosen point is uncovered from this facing, penetration is irrelevant. Keep aiming there if you can hit it consistently.
2Check the worn classUse the effective class shown for that shot, not the pristine badge. A plate can cross into a different matchup during the burst.
3Check the outcomeA stopped hit can still wear the piece down, but feeding a strong plate is costly. Compare that route with an uncovered zone.
4Check repeatabilityThe quickest possible head reading is not automatically the shot you can repeat. Compare it with the aimed and spray verdicts.

Need the arithmetic?

Curves, branch behavior, damage and model limitations live in one place.

Open Damage Model

Choosing a round?

Use the beginner decision guide without memorising probability tables.

Choose ammunition

Testing a loadout?

Set the target’s gear, condition and facing in the simulator.

Use the simulator

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Penetration Mechanics Explained

Coverage comes first

Body armour

Helmet and face shield

Durability changes the matchup

Fresh

Worn

Broken

Turn the reading into a decision

Need the arithmetic?

Choosing a round?

Testing a loadout?

Related Guides

The Damage Model, Step by Step

Ammunition Selection for Beginners

How to Use Combat Sim

Coverage comes first

Body armour

Helmet and face shield

Durability changes the matchup

Fresh

Worn

Broken

Turn the reading into a decision

Need the arithmetic?

Choosing a round?

Testing a loadout?