Webby creating multiple layers of protection and establishing fallback positions, castle defenders gained a tactical advantage over besieging forces. Webwilliam gurstelle’s defending your castle: Build catapults, crossbows, moats, bulletproof shields, and more defensive devices to fend off the invading hordes Webdefend your castle takes place on a grassy plain surrounded by invaders. You are the commander of your castle, and at your disposal is an invisible hand for picking up the. Web“ever feared that raging viking or mongol invaders are about to attack your home?