War of Plundering
War of plundering is the war between two kingdoms at a kingdom center. It strictly means to gather booty and is generally less severe than a war of conquest. The armies will do battle until at least one side is reduced in strength by 50%, and therefore, the loss on both sides are usually smaller. Different than wars of conquest, the gain of the victorious kingdom is a gold booty instead of land.
One other distinct feature of plunder wars is that the defender also takes civil and spy casualty in addition to military casualty. Both civil and spy casualty can be 20% at maximum. Their rates depend on the magnitude of military casualty taken. So, when the military casualty after a plunder is high for the defender kingdom, civil and spy casualty also will be high.
In a plunder attack, the attacker has to pay a war cost to mobilize the army. This adds another dimension to plunder wars. Even if the attacker kingdom becomes victorious, it can loose high amounts of gold from a plunder war, because war cost can exceed the booty taken. This is very likely when the attacker goes to battle with an large army and defender has a small amount of gold in its treasury.