This chapter redefines artistic authorship as an external, emergent sign that self-organizes within the niche of semiotic artifacts. Authorship is classified as a legisign (a general, regular pattern or law that is a sign). This legisign exerts a downward determinative influence on the artistic practice, meaning the artist’s agency is a distributed property of the niche, making the artist a participant rather than the sole intentional originator. By utilizing sign classes, authorship can be analyzed across iconic (style), indexical (agent’s existence), and symbolic (legal/conventional habit) connections.