I just have a question that there doesn't seem to be a straight answer to in the rulebook.

If someone attacks an objective, and the defending player declares no defenders, the attacker doesn't have to strike to get the unopposed bonus right? I was just wondering as that has been the way we have been playing it. It definitely makes leaving your board vulnerable a bad thing, but it also seems pretty insane with cards like Han and any of the shielding protectors. Just wondering.

You can not opt to not strike during an engagement. If you aren't exhausted, you must strike.

Ah cool. Thanks for that. Appreciate the help.

There is a very straight answer in the rule book on page 20 under Resolve Strikes: "A Player does not have the option to pass during this step. If he has at least one ready participating unit, it must focus to strike."

Yeah, I should have given in a thorough read through. Thanks for the help though.