This paper explores the roles and practices of collective citizen engagement in spatial planning. Drawing on a selection of core articles in planning scholarship, it investigates how citizens (re-)shape urban places by responding to perceived flaws in how spatial planning addresses societal challenges. Formal planning interventions are often spatially and socially selective, ineffective, or even non-existent due to a lack of institutional capacities and resources. Consequently, citizens take on roles that they consider as missing, underperformed or ineffective. The paper shows that this results in a variety of practices complementary to, independent from, or opposing formal planning actors and interventions. Five dilemmas citizens face are identified, highlighting the tensions that surface on exclusion, participation, and governmental responsibilities when citizens claim their role in urban governance.