This Element considers the concept of performance diagrams and shows their historical, epistemic and aesthetic functions in theatre and dance. In three sections, the author surveys the architectural model of theatre by Vitruvius, the woodcut of Marlow's Doctor Faustus, Aby Warburg's Mnemosyne-Atlas, the spells and drawings of Antonin Artaud, the performance Paradise Now (the Living Theatre) and the choreography I am 1984 (Barbara Matijević). Demonstrating that diagrams can be applied to multiply dramaturgical trajectories, the text reviews their relevance for performance-making, analysis and documentation. The author argues that diagrams provide new tools for theory, practice and archiving, while at the same time enabling reflection on the intersections between poetics and politics. Focusing on the potentiality of diagrams to cut through representation and dichotomies, this Element affirms the visual, corporeal and spatial dimensions of performance-making. In doing so, it elucidates the significance of diagrammatic thinking for performance studies.