Choose to use Pierce? And Pierce vs Impervious?

[crowofgames]

It seems clear that with Pierce you may choose to cancel up to X block results. And with that choosing, you could in theory not use Pierce one time to keep one trooper alive in a unit so as to keep the attacker engaged in melee and therefore unable to be shot at range.

 

Can you just choose not to add Pierce to the attack pool to begin with? I am wondering how this choosing interacts with the Impervious keyword. Can you simply choose not to use Pierce to begin with and therefore not grant the extra dice from Impervious?

Edited May 3 by crowofgames

[TalkPolite]

Hello, 

From the Core Rulebook: "While a unit with the Impervious keyword is defending, it rolls a number of extra defense dice equal to the total Pierce X value of weapons in the attack pool. "

2 hours ago, crowofgames said:

Can you just choose not to add Pierce to the attack pool to begin with?

If the attacker chooses not to use any of their Pierce x value, Impervious will still trigger, because it is based off the value of Piers X of the weapons in the attack pool, not how much was used in the attack. 

Hope that helps,

TP