Retained vs Modified Dice

Some Kill Team rules turn a normal success into a critical success. Some do not work on every normal success you are holding. Which ones depend on a single line of wording, and it is easy to miss at the table.

This page explains the rule, sorts every effect the calculator supports into the two camps, and shows exactly what the engine does with each.

The rule

A dice can only be retained once.

When you retain a dice, you are declaring what it is — "this is a normal success" — and putting it down. That declaration is spent. A later rule that asks you to retain that dice again, as something better, has nothing left to work with. The dice is already locked in.

A rule that instead asks you to change a success you are already holding is doing something different, and it works fine on a dice that has been retained.

So the wording is the whole rule:

The clearest case is a cover save. You retain it as a normal success without ever rolling that dice. It is retained, immediately and permanently. A rule offering to retain a normal save as a critical save instead cannot touch it — there is no un-retained dice there to retain.

When all of this happens

All dice are retained and modified before any hits are resolved. Every effect on this page happens in the dice step, while you are looking at your roll and deciding what to keep. Once the shooting or the combat starts resolving, the dice are what they are — you cannot hold a promotion in reserve and spend it later, after seeing how the first few hits land.

The one thing that does happen during the dice step is Devastating x, which inflicts its damage the moment a critical success is retained. That still doesn't let you defer a decision: it means a promotion which creates a critical success pays out immediately, not that you may wait and see.

That matters for reading the calculator's numbers: when it decides whether to take an optional rule (Punishing, Accurate, Mystic Scry), it is making that decision once, in the dice step, exactly as a player must. It never adapts the choice to how the damage turns out afterward.

Which effects lock a dice

These produce a normal success that has already been retained. Nothing worded as a retention can promote them afterwards.

Cover and Accurate are obvious — the dice was never rolled. Punishing and Mystic Scry's fail rescue are the ones people miss: they save a fail by retaining it, so that dice has now been retained once and is closed to further retention. That is why taking Mystic Scry's fail→norm option does not hand Rending another norm to promote.

Which effects can act on a locked dice

These change or promote a success rather than retaining one, so an already-retained dice is a legal target.

Which effects are blocked by a locked dice

These are the retention-worded promotions. In the calculator they draw only from normal successes that came off the dice.

How the calculator models it

The engine keeps a count of how many of your normal successes are already retained, alongside the normal successes themselves. Every retention-worded promotion is offered only norms − retainedNorms as legal targets. Everything lives in one shared step (applyPostRollModifications), so the exact Shoot calculator and the Monte Carlo Fight calculator behave identically here.

One refinement worth knowing about: when a change-worded effect (Severe, Waaagh) consumes a normal success, the engine deliberately spends a retained one first. This is never worse for you and is sometimes better, because it leaves your rolled dice available for any retention-worded promotion that comes afterwards. It is not extra generosity — it is what a player who understood the interaction would do.

Worked examples

Cover save vs NormsToCrits. You are in cover (1 automatic normal save) and have a rule letting you retain a normal save as a critical save. One critical hit is coming in.

• The cover save is retained. It cannot be promoted.
• You are holding 1 normal save. A single normal save cannot cancel a critical hit (that takes two).
• Result: the hit goes through.

Rolled save vs NormsToCrits. Same rule, but the normal save came off a die you actually rolled.

• The save is promotable. It becomes a critical save.
• A critical save cancels a critical hit.
• Result: the hit is cancelled.

Both at once. One cover save, one rolled normal save, one promotion available. The promotion goes to the rolled save — it is the only legal target. You end up holding 1 critical save and 1 normal save.

Punishing then Rending. You retain 1 critical hit and 1 fail.

• Punishing retains the fail as a normal hit. That dice has now been retained.
• Rending asks to retain a normal hit as a critical instead — but the only normal hit you have is the Punishing one, already retained.
• Result: 1 critical + 1 normal. Not 2 criticals.

Taking Punishing is still right here: declining would leave you with the critical hit alone. It stops being right only when something else can turn that same fail into a promotable norm — see the optional-rules section below.

Severe ordering. You have 1 rolled normal success and 1 Accurate normal success, plus Severe and one NormsToCrits promotion, and no criticals.

• Severe changes the Accurate success to a critical (change-worded, so it may).
• That leaves the rolled success free for the NormsToCrits retention.
• Result: 2 criticals. Had Severe taken the rolled success instead, the Accurate one would be unpromotable and you would end at 1 critical + 1 normal.

Optional rules the calculator decides for you

Three of these effects are optional — Punishing and Mystic Scry say "you can", and Accurate lets you retain "up to x" — so taking them in full is a choice, and not always the right one, because the dice they produce are locked. The calculator resolves every line and keeps whichever ends better, deciding in the dice step exactly as a player must.

Punishing. With 1 critical hit and 1 fail, Rending, and FailsToNorms 1:

• Taking it: the fail becomes a locked norm, leaving FailsToNorms nothing and Rending no legal target → 1 critical + 1 normal (7 damage at 3/4).
• Declining it: FailsToNorms converts the fail to a promotable norm and Rending promotes it → 2 criticals (8 damage).

The calculator declines. Whenever nothing else wants the fail, it takes the retention as usual.

Mystic Scry. Retain one fail as a normal success, or one normal success as a critical success, or decline. The norm→crit half needs a norm that isn't already retained, and the fail→norm half produces a locked norm that Rending then can't promote — so the calculator scores all three lines through the remaining steps and keeps the best. Its own page, /notes/mystic-scry-buff, works through the Rending interaction.

Accurate. The rule is "retain up to x dice", so retaining fewer is legal. A retained dice is locked, while rolling it can produce a critical success or a promotable norm. With one die at 2+ and a spare norm→crit promotion, rolling is worth 3.33 damage against a retained norm's 3.00 — so the calculator rolls. It keeps the maximum whenever that is at least as good, which is the usual case.

Known modelling limitations

Cover saves are always taken. Cover is optional in the same way Accurate is, but ranking the choice properly needs the incoming hit profile — a normal save is worth half a critical save only against critical hits — which the dice step cannot see. It is a narrow corner: measured against a normal attacker, cover wins at every save value and every promotion count, and declining only pulls ahead once you hold norm→crit save promotions and most of the incoming hits are critical. When Not to Take Cover Saves has the numbers and the workaround.

Optional rules are ranked on pre-save damage. When the calculator decides Punishing, Accurate or Mystic Scry, it scores the options by the damage the dice would deal, without weighing the defender's saves or Piercing. For save dice, where there is no damage to score, it falls back to counting a critical save as two normal saves.

FailsToNorms is treated as a change, not a retention. The generic input is worded as a modification, so the norms it produces stay promotable. If your rule is worded "retain one of your fails as a normal success", the resulting dice should be locked instead. Punishing is the locked-and-modelled version, but note it is conditional: it only triggers when you have at least one critical success, and it is switched off entirely by an Obscured target. An unconditional retention-worded fail rescue therefore has no exact representation right now — FailsToNorms will slightly overstate it on rolls where the resulting norm goes on to be promoted.

Quick reference