The chapter focuses on the (potential) institutional changes introduced by strategic spatial planning (SSP) episodes and different forms of innovation and effectiveness in planning. It reflects on the procedural and institutional dynamics that occur in different planning systems in the long run, while this book offers a great opportunity to overview episodes and practices of SSP in different world-wide contexts (see chapters in Part 1). As Friedmann stated, ‘All planning must confront the meta-theoretical problem of how to make technical knowledge in planning effective in informing public actions’ (1987, p. 36). In this perspective, the debate about planning systems and planning theory encompasses an umbrella of different theoretical reflections that have conceptualized ways to achieve effectiveness (intended in its broader meaning) in a constantly changing environment (Hillier, 2011). Within this domain, SSP became one of the most powerful answers to the request for effectiveness of planning processes.