This chapter begins with the use of the planning theory of individual temporally extended human action in a construction of shared intention. It then develops a series of further constructions that build on each other: of Hart-type, criticism/demand-involving social rules; of authority-augmented social rules of procedure involved in the rule-guided infrastructure of an organized institution; of institutional intentions as outputs of social rules of procedure (where these intentions require neither corresponding shared intention nor a dense, holistic institutional subject); and of institutional intentional agency. These constructions articulate inter-related roles of our capacity for planning agency in important forms of human practical organization: temporally extended, small-scale social, and institutional.