I had an opponent in Sullest argue that Brace could cancel my crit effect (Assault Concussion Missiles specifically). I'm pretty certain that's not right. Here's my logic. Check it please?

Brace C : When damage is totaled during the “Resolve Damage” step, the total is reduced to half, rounded up.

Attack steps (relevant ones only)

4 . Spend Defense Tokens: The defender can spend one or more of its defense tokens.

5 . Resolve Damage: The attacker can resolve one of its critical effects. Then the attacker determines the total
damage amount. Then the defending squadron or hull zone suffers that total damage, one point at a time.

The way it works in my mind:

1. So I roll my attack, get the black crit necessary to trigger ACM and some other damage.
2. Defender spends Brace.
3. I resolve the ACM crit effect, doing 1 damage to each adjacent hull zone to the target.
4. Total the remaining damage, Brace then cuts that in half.

My opponent argued two different things, both "wrong" in my opinion. First, that Brace cut in half the "extra 2 damage" from ACM. Second, that he could "cancel the crit" die by cutting my damage in half (effectively cutting the dice damage icons in half).

To me, the rules are very clear. Brace only reduces the total damage by half, it doesn't cancel or remove any dice results. And the ACM crit effect is complete independent of Brace.

Brace just's halves damage. It does not cancel dice icons or dice.

Nor does it affect ACMs in any way.

The way it works in your mind is very close (or exactly) the way it works in the rules.

As mentioned the Brace token doesn't cancel out half of the dice/dice icons. It reduces the sum of the total damage that the dice deal. Critical effects are, and probably always will be, separate from normal damage dealt, even if they deal damage.

I suggest you to advise this player to at least glance at the rulebook.

Icons are different from Damage. Icons don't get cancelled except from evades at the range that they cancel dice.

Also Brace doesn't take effect whent he token is spent. It doesn't even take effect until after critical effects are chosen and for the most part resolved. Brace has zero effect on critical effects. Evades are a special case because they straight up cancel a die so it is not around for you to use it as a critical effect.

Also Brace doesn't take effect whent he token is spent. It doesn't even take effect until after critical effects are chosen and for the most part resolved. Brace has zero effect on critical effects. Evades are a special case because they straight up cancel a die so it is not around for you to use it as a critical effect.

Evades occur during the Spend Defense Tokens, Brace during the Calculate damage step, Redirect occurs when damage is being dealt (you decide hull zones now), and Contain occurs when you take a standard critical (this may occur during the selected critical effect step, hmmmm)

This one is addressed directly in the FAQ/Errata:

Assault Concussion Missiles
The damage caused by this card cannot be reduced by the [brace] defense token.

If the Evade canceled the crit, or caused a reroll, that would cancel it. Otherwise, it goes off (anytime you have a black crit, unless you choose the standard effect for some reason.) You only get one crit effect (standard or otherwise).

This one is addressed directly in the FAQ/Errata:

Assault Concussion Missiles

The damage caused by this card cannot be reduced by the [brace] defense token.

If the Evade canceled the crit, or caused a reroll, that would cancel it. Otherwise, it goes off (anytime you have a black crit, unless you choose the standard effect for some reason.) You only get one crit effect (standard or otherwise).

That FAQ entry doesn't pertain to the issue at hand. That the Brace can't do anything with the damage from the effect doesn't deal with the OP's opponents assertion that a Brace essentially removes dice from the attack roll, instead of just ignoring half the total damage. It's simply a matter of his opponent not knowing basic rules unfortunately.

You have the correct answer, you are just applying the wrong stuff