The Core Set is one of several Pathfinder Adventure Card Game products. It contains everything that 1–4 players need to begin the game and play through The Dragon’s Demand Adventure Path.
Products available separately include Adventure Path products, such as the Curse of the Crimson Throne Adventure Path, that offer new locations to explore, new villains to fight, new loot to acquire, and much more. Also available are a variety of class decks, which include new characters along with a variety of cards that are useful for those characters.
To play The Dragon’s Demand with 5 or 6 players, you’ll need to either add characters from an Adventure Path product, or add 1 class deck for each additional player. See the storybook for details.