Your vest is a wall with a health bar
Every bullet chips the wall, even the ones that bounce. While the wall is healthy, bullets bounce. Once it drops past a certain point, every bullet goes through. Nothing random about it.
Lv6 vest vs M995
00 / TL;DR
No math version
Skip the formulas. This is how armor works in plain words, with what happens to each bullet. bounces goes through coin flip
A Lv6 vest is half a vest
Against BS, M995 or DVC the wall breaks at around half durability. That means it stops about 3 bullets. After that it's decoration that slows you down.
breaks at ~56%
A Lv5 vest stops nothing
Against the meta Lv5 rounds a brand new Lv5 vest is already broken. Every bullet goes through from the first shot. It only makes each hit hurt a bit less, so you live one extra bullet.
Lv5 vest vs BS
Helmets roll dice
Helmets and face shields are different. A fresh Lv6 helmet always stops the first hit. After that each hit is a small gamble, and once it's worn enough everything goes through.
Lv6 helmet
Always repair to full
Armor only looks at the percentage. A vest at 50/100 is at 50% and stops nothing. Repair it to 50/50 and it is back at 100%, and it stops 2 bullets again. Same vest, same durability.
50/50 after repair
Not every Lv6 is equal
Same level, same protection, but some pieces wear out way slower. An IND70 helmet takes about one more bullet than an SH65 before you drop. Check how fast it wears, not just the level.
IND70
Shot through the arm?If the bullet goes through a hand, arm or shoulder before it hits the vest, it always passes through the arm and keeps 88% of its damage. Its penetration stays the same, so the vest breaks at the same point, the hits just hurt a bit less. Flip "Through the arm" in the range to see what it changes.
Repair after every raidto full. Under 56% your vest stops nothing until you repair it.
Skip Lv5 vestsif you expect them to stop meta ammo. They won't.
Wear a face shielda helmet without one dies to a single face shot. RST, 6BNT and SH65 take a matching mask.
Buy slow-wearing helmetsIND70, AS200 and RST hold up the longest.
Look at enemy loota Lv6 vest under half durability is barely worth carrying.
01 / RANGE
Put rounds into it
Pick a piece, pick a round, set how worn or repaired it is, then fire. Every shot shows the effective protection, the pen chance and the roll.
Slot
Gear
Round
New
weapon + barrel
Repair state
Hit path
Through the arm = the round passes a hand, arm or shoulder first and keeps 88% damage. Pen and armor wear are assumed unchanged.
Next shot0%pen chance
Effective protectionRound penAlways penetratesChance zone once damaged
Shots to kill
Shot log
Bare body parts · no armor
Only head and thorax kill. A blacked arm or leg does not end the fight. A hit on a part already at 0 spreads its damage to other parts (the game shows "Damage Spread"), but how much goes where is not confirmed yet, so it is not counted here.
02 / LEDGER
What your Koen buys
Every piece ranked by what it costs per extra bullet you survive compared to wearing nothing. Lower is better. Click a column to sort.
03 / RULES
How the game decides
The formulas behind every number on this page, read from the ABI Tracker simulator and checked against the shots above.
R1
Protection decays with durability
A Lv6 piece is 60, a Lv5 is 50. The ratio is measured against the item's current max, so a repair keeps the breaking point at the same percentage and only shrinks the pool you have before it.
ratio = current / max
rate = min(1, 1.21 − 50 / (200 × ratio^1.2 + 45))
effective = level × 10 × rateR2
Vests Lv5+: no RNG
- Pen ≥ effective protection: goes through, 100%.
- Pen below it: stopped, 100%. Only blunt damage.
- Fresh Lv5 = 50. BS, M995 and DVC12 are 52–53, so they go straight through from shot one.
- Lv6 breaks at 56.4% vs BS/M995 and 59.9% vs DVC12.
R3
Helmets and shields roll dice
- Full durability, protection above pen: 0%. The first hit on fresh Lv6 is always stopped.
- Damaged, protection above pen by up to 10:
chance = ((pen − effective) × 0.02 + 0.31) × coef
- Starts near 15% for BS/M995 and climbs to ~31%.
- Protection at or below pen: 100%.
R4
Damage and wear
pen hit = (dmg + bonus) × mult(pen − level×10)
diff < −10 0.60
−10 … 9 0.65 + diff × 0.005
9 … 19 0.80 + diff × 0.01
> 19 1.00
blocked = (dmg + bonus) × blunt rate
wear/hit = armor damage × drain scaleR5
Drain decides the winner
Every Lv6 helmet has 60 protection, but they wear at very different speeds. The IND70 loses 45% of a round's armor damage per hit, the SH65 105%. That is the difference between dying in 3 shots and in 5.
R6
Assumptions
- Body HP, from the in-game damage screen: head 40, thorax 85, abdomen 70, each arm 60, each leg 65. Only head and thorax are lethal. Damage that lands on an arm or leg already at 0 is not modelled yet.
- Distance: pen is multiplied by a curve of distance ÷ the weapon's effective range (read from simulator logs of 5.56 M995 and 7.62x54; assumed the same for every Lv3–Lv5 round). Damage drops to ×0.7 beyond the effective range. Barrels change the effective range, so you can edit it.
- Arm hits: a round passing a hand, forearm, upper arm or shoulder first (secondary hit zone) goes through 100% and keeps 88% damage (Secondary Pen. DMG Factor). We assume pen and armor wear do not change, the data doesn't say.
- Thorax 85 HP, head 40 HP, as in the simulator. Face hits count against the same 40 HP, so with no face shield any meta round kills in one face shot.
- Helmet and mask pairs are matched by name (RST, 6BNT, SH65). DOD9 and IND70 cover the face themselves.
- Pen coefficient 1.0 on every helmet and shield.
- Helmets and shields more than 10 points above pen use a per-item "pen constant". It was 0 in every log we read, so it is 0 here. This mostly matters for Lv4 rounds against Lv6 helmets.
- Durability drain for every piece comes from the ABI Tracker armor table (data version 20261014).