From the description: Clashes is a small supplement designed for Beak, Feather & Bone that introduces rules for events, changes and occurrences that happen as you play. You'll need a copy of Beak, Feather & Bone to play. Clashes are designed to bring action and change into your game of Beak, Feather & Bone. It's one page of rules for introducing events into your town. You might describe how an NPCs rivalry makes its mark on the city or how a building - once important - is found to be crumbling and unstable.