A gaming machine for conducting a wagering game includes a plurality of game cards that may be read by one or more card readers of the gaming machine. The game cards may provide a variety of enhancements for the gaming machine, including enhanced game features, enhanced rules of game play, enhanced game characters, and the like. Players may collect the game cards for use in the gaming machine in hopes of increasing their likelihood of achieving a desirable outcome or altering the characteristics of the game to offer more entertaining variations on game play. The players may also trade the game cards with one another and with the casino, thereby creating excitement and interest in the gaming machine. Special interest groups and even entire industries may be formed to facilitate the collecting and trading of the game cards.