If your home base has damage protection, keep in mind that while your base is protected, your battalions and quarries outside of home base will still be vulnerable to enemy attacks. If you want to keep your battalions protected, we advise sending your troops back home so that they won't be vulnerable to enemy attacks.
If you attack a rival's battalion, quarry, or home base while under damage protection, you will lose your damage protection as a result of the attack.
For a broader look at how damage protection works in general, please refer to this FAQ: http://bit.ly/Qbou8l
Keywords: Attack, Damage, Protection, PVP, Battalions, Quarries