The past decade has seen a gradual but steady increase in the use of games in participatory planning practices. Since the 'Gamification' gained momentum, the thoroughly thought-through simulation and gaming discipline of the 1970s has been replaced by an amalgam of confusion and optimism about the role and added value of games in planning practice. The lack of clarity about what games really are and the scarcity of studies on how they can be used in dealing with contemporary participatory planning concerns have limited the use of digital games in planning to pedagogic and communication purposes.This research contributes to debates on the role and added value of digital games in participatory planning practices by unravelling the types of knowledge that can be produced by digital games and the many ways in which data flows happen between the real world and the imaginary world of games. To do so this research focuses on the epistemological analysis of digital games and core concepts of participatory planning, democracy and power, using a four-staged problem-centred Design Science Research (DSR) approach; 1) it first explores the existing limitations and potentials of the use of games in scientific fields in general; 2) it reviews the role of knowledge in participatory planning practices and its consequent effect on the defined role of games; 3) it proposes a new framework for using games as a research tool in participatory planning which conceptualizes games as artefacts with embedded information system; 4) it validates the framework by designing, testing and evaluating a game, called Mythoplastis with the aim of capturing the perception of the public about various locations in Manchester, UK.The study concludes that while games are powerful tools for capturing mental model of their players, the dominant gaming and simulation legacy and the emphasis on the scientific validity measures cease planners to be open or receptive to the artistic values of digital games and their potential in being used as research tools. It shows that by bridging the gap between commonly ignored theoretical and practical efforts of main stream game designers with the serious game design frameworks, new conceptions and roles of games can be explored. The designed game, Mythoplastis, shows how real world data can be abstracted in the game world for research purposes. It is also argued that for participatory planning to move beyond generalized and deterministic discourses about the role of planners and supporting tools, it is crucial for planners to re-examine the role of knowledge and validity measures in the conception of participation in planning.