Ok, it's the middle ages. Middle of what you ask? Well I guess anything after the beginning and before the end is the middle.
Never mind that. You are a Baron, and you have a sweet Barony. Problem is, so do all the other Barons. And worse, they want to take your Barony over and turn it into Ye Olde Golfe Course.
So you did what any good baron would do, and built a castle fortification to protect your lands. And then they did too, even though it was YOUR idea first.
So you built a secret weapon. Well not a secret really, because it's like 30 cubits high and you can't hide something 30 cubits high. It's a catapult. Having your catapult has allowed you to come up with a cunning plan. It goes as follows.
1. Build Castle. 2. Launch rocks and break other people's castles. 3. Profit.
So a light breakfast then, and then on to rain down destruction on my rivals.
A clash of Catapults allows you to construct a castle with castle cards and then, using a dexterous flick of the card, destroy your rivals castles for fun (and profit).