What determines the success of my agent operations / magic spells?
Basically the amount of agents/wizzies you have, the amount of agents/wizzies your opponent has and both your NW’s. Also with magic both the magic race bonuses count. When you op/spell someone with a bigger NW than you it will be about sheer number of agents/wizzies. When you op/spell someone with a lower NW than you it will be about amount of agents/wizzies per NW. Also note that with both the actions there’s a probability factor as well. So even if you have a lot more wizzies/agents than your opponent you can still fail due to bad luck!
