Appearing for the first time in English, Karl Anton Nowotny's Tlacuilolli is a classic work of Mesoamerican scholarship. A concise analysis of the pre-Columbian Borgia Group of manuscripts, it is the only synthetic interpretation of divinatory and ritual codices from Mexico. Originally published in German and unavailable to any but the most determined scholars, Tlacuilolli has nevertheless formed the foundation for subsequent scholarly works on the codices. Its importance extends beyond the study of Mexican codices: Nowotny's sophisticated reading of these manuscripts informs our understanding of Mesoamerican culture. Of particular importance are Nowotny's corrections of errors in fact and interpretation in the Spanish edition of Eduard Seler's commentary on the Borgia Group. George A. Everett and Edward B. Sisson have translated Nowotny's masterwork into English while maintaining the flavor of the original German edition. To the core text they have added an extensive bibliography and constructed a framework of annotation that relates the principles in Tlacuilolli to current research. This edition includes a selection of eleven stunning full-color images chosen from the original catalog.