From publisher blurb:
Cardcaster's Gamble adds a variety of new content for Spheres of Might and Power focused around gambling to empower your abilities or utilizing the magic of the harrow deck or casting via cards.
Included in this book are:
Class Options The harrow medium archetpe for the medium which allows them to call upon the power of the harrow deck, the gambler archetype for the thaumaturge granting them blended training and new gambling-focused features, and the fortuneteller path for the hedgewitch which allows them to manipulate the luck of their allies and their foes!
Casting Drawbacks Gamble for your power with the spell gamble drawback, or utilize a brand new system of casting by turning your spells into cards using the card casting drawback!
Feats 21 new feats focused around gambling and cards, including new categories of feats! Ante feats let you utilize the new ante system to gamble with your in-combat potential, and deck feats modify how you may use your card casting!