My friend shot my imperial guardsman with chewie, he rolled 2 hits, I rolled 1 defense. With pierce 1 would he cancel out the one defense I rolled so I’d take 2 wounds? or would I only take 1 wound because my block canceled 1 hit. Thanks!

Pierce X cancels X block results. So in this case his Pierce 1 cancels your 1 Block result, so his 2 hits go through.

On page 54 of the RR speaks of this, though indeed not as informative as one may like...

Quote

During the “Modify Defense Dice” step of an attack, a unit whose attack pool includes a weapon that has the pierce x keyword can cancel up to x block results.

While the above answer is correct, I'd like to lightly expand on it since many others have had the same question throughout the game.

A lot of "veterans" (Been playing for a while yet still never learned the game correctly) tend to use shortcuts, which typically confuses those who are still learning...and even those who do already know the rules lol. It's a lazy way of doing things, which I could never agree with personally. A lot of the time it's actually incorrect with a aspect of truth mixed in, which doesn't make it correct like they think it does. Which the source of this question comes from!

Like the classic Darth Vader has pierce 3, so lets do auto 3 hits on top of what results you get. It isn't auto 3 hits! The real rule is you still roll your normal defensive roll, then subtract afterwards the result. That certainly could be way more than just auto 3 hits, and with impervious it might even end up with less!

One example of a legit shortcut, though still should be played out without yet certainly may if both understand the rule... would be, a unit of imperial scout sniper shoots at a stormtrooper unit, which is heavy cover. The scout sniper rolls one critical hit... you could just shortcut saving time by auto eliminating one stormtrooper, OR (do it the lengthy same result way) The scout sniper removes 1 cover, making it light cover which still doesn't apply against a critical hit, the defender rolls One defense die, literally anything and everything they could roll is either fail or negated, which ends up being one hit.

While in the prior point about for example purposes darth vader ... Commander Darth Vader does a melee attack against Boba Fett, rolls 6 red dice which equal say 5 hits/crits (doesn't matter about specifics in this example) with pierce 3. Boba Fett rolls 5 red defensive dice + 3 more because of impervious. Out of the 8 red dice he rolls 7 blocks, minus 3 from the pierce equals 4 blocks and 1 hit successful. Big difference compared to auto 3 hits!

While I could greatly expand on the topic, this should be enough. Hopefully this helps, if I made an error please feel free to assist.

11 hours ago, krebeck said:

My friend shot my imperial guardsman with chewie, he rolled 2 hits, I rolled 1 defense. With pierce 1 would he cancel out the one defense I rolled so I’d take 2 wounds? or would I only take 1 wound because my block canceled 1 hit. Thanks!

Why are you only rolling one die?

34 minutes ago, arnoldrew said:

Why are you only rolling one die?

Pretty sure he means his dice roll resulted in 1 Block result.

3 hours ago, Lochlan said:

Pretty sure he means his dice roll resulted in 1 Block result.

Aha, I think you're right.

10 hours ago, Lochlan said:

Pretty sure he means his dice roll resulted in 1 Block result.

That is correct I rolled one block