Yep, there is no cost to you when you defend from an attack. Plus, with the recontextualizing of Personnel, treating it like Wealth, it becomes a variable. 1 W = $10,000 or $1 mil. 1 P = 10 people, 100 people. By this way, you can roleplay that you have enough Personnel to protect yourself. Though, those with Gyfts will always be stronger... if you're worried about an attack, you could always make a few more NPC sheets. :>