In Mad Barrington's Gyre players compete to accumulate the shares worth the most bottle caps by the end of the game. "Why bottle caps?" Because in the post-apocalyptic future of flying castles, giant robber baron cockroaches and mutated broccoli.... bottle caps are the coin of the realm. Each player starts with a identical set of cards and can play, buy or sell cards each turn that improve their deck's purchasing power or allow them to impact the value of shares (Guns, Ammo, Food, Water, Meds & Pennies) directly or indirectly through rumour cards or affecting the number of stock value cards in play. Shares are bought and banked separately from each player's main deck but the stock value cards that determine the value of the shares are bought and sold from a common pool that is manipulated by the players throughout the game. As well, each player has a character card that gives them a distinct bonus in the game ranging from Humbles Wuggles-Roach's ability to buy Ammo shares at a reduced rate to Lord Fat Pockets ' improved starting bottle caps and Mad Barrington's ability to buy rumour cards on the cheap.