Hero Realms: Thief Pack - Rules of Play says:
Play Hero Realms as a cunning Thief. Through sleight of hand, your enemies' riches will become your own. Few can catch you, and those who do will soon feel the point of your knife! This Character Pack replaces a player's personal deck in the Hero Realms Deckbuilding Game. Included are 15 cards: a Thief character card, the Heist and Pickpocket ability cards, two unique scorecards, and a new 10-card personal deck (2 Ruby, 3 Throwing Knife, and 5 Gold).