High-stakes gambling was a widespread pastime in the courts of early modern Europe and the Medici court in Florence enjoyed a particular notoriety for it in the middle decades of the sixteenth century. Using insights from the sociological writings of Johan Huizinga, Erving Goffman, and Clifford Geertz, this article explores the meaning and significance of games of chance in the ducal household, focusing specifically on the gambling habits of the duke and duchess, Cosimo I de’ Medici and Eleonora de Toledo. It argues that play in the Medici court was always more than simple diversion and that the ducal couple used gambling to demonstrate their self-control, fortitude, and suitability for governance. Play, the article suggests, was a constitutive element of court culture in early modern Europe.