This full-length study investigates how sermons and vernacular religious drama worked as media for public learning, how they combined this didactic aim with literary exigencies, and how plays acquired and reflected authority. The interrelation between sermons and vernacular drama, formerly assumed to be a close one, is addressed from historical connections, performative aspects, and the portrayal of penance. The work demonstrates the subtly different purposes and contents and outlines the unique ways in which they operate within late medieval England.