How KT Calc works

KT Calc is open about its math. These pages explain the logic behind the numbers — the surprising results worth a closer look, and the Kill Team 2024 rules the engine is built and validated against. Read through if you want to check the calculator by hand or understand why a result came out the way it did.

Deep-dive notes

Lethal + Relentless: why kill chance can rise as BS gets worse →

Walks the math for a scenario where the reported kill chance is higher at BS 5+ than BS 2+. Not a bug — Relentless feeds every failed die back into a fixed crit band, and kill chance is a tail probability, not an average.

Mystic Scry Buff + Rending: why the best choice depends on what you rolled →

The "retain a fail as a norm, or a norm as a crit" decision is not fixed. Explains when each choice wins and how the calculator models it.

Why Punishing can lower your damage →

Switching on an ability that only adds a hit can reduce reported damage. Punishing retains the fail, locking it, where another effect would have left it promotable — so the promotion is stranded.

Comparing weapons by power level →

Which weapons are actually the same power level, measured against a fixed slate of targets — plain and with the buff that upgrades them, because a set that looks even can still come apart once everyone is buffed.

Game rules reference

Combat rules — defense & the shooting save sequence →

Defense dice, saves, cover, Feel No Pain, Piercing, and Saintly Relics — how the shoot calculator resolves saves.

Fight rules — how melee is resolved →

The alternating strike/parry sequence, what a parry can cancel, the engine’s strike-vs-parry decision logic, and hand-verifiable scenarios.

Retained vs modified dice — why cover saves cannot be promoted →

A dice can only be retained once. Sorts every effect into the ones that lock a dice (cover, Accurate, Punishing) and the ones that can still change it (Severe, Waaagh), and explains what the calculator does with each.

When not to take cover saves →

Cover is optional, and occasionally worth declining: with norm→crit save promotions against a mostly-critical attack, rolling the dice beats a locked normal save. Measured numbers, plus why the calculator always takes cover.

Weapon rules — all weapon rule effects →

Reference for every weapon rule the calculator supports: Accurate, Balanced, Brutal, Ceaseless, Devastating, Heavy, Lethal, Piercing, Punishing, Relentless, Rending, Saturate, Severe, Shock.

← Back to calculator

Open source on GitHub — Pull requests welcome!
Forked from https://jmegner.github.io/KT21Calculator/

⚔️ Alternative Tools

Ballistica Imperialis →

Alternative KT math tool with preloaded weapon & defence profiles and a cool design.

NemesisForge →

Build your own nemesis operatives.

How KT Calc works →

Deep-dive notes and the Kill Team rules the calculator is built on.