The goal of this chapter is to articulate an agenda for the study of collective communication design. The chapter begins with an introduction to communication as design (CAD) and then presents distinctions between individual and collective objects and subjects of communication design. Messages, interaction architectures, moments, and flows are explored as categories of communication design activity. The chapter ends with a discussion of CAD as normative, practical theory, and makes the case that communication effectiveness depends on communicators' reflexivity, the sophistication of their models of communication, and their skill and ability in enacting preferred designs for communication. The intersections between individual and collective communication design should empower theoretical efforts to understand and explain interventions in organizing through communication.