The Metropolitan Heritage answers metropolization's impacts on the vulnerable cultural heritage contexts. Given the subject complexity, territories and environments' fragmentation, and the diversity of stakeholders, the MEMORANDUMgame Training is conceived for all the metropolitan agents (decision-makers, civil servants, civil society and Institutions) as a creative and practical pathway towards metropolitan project impact on cultural heritage. The practice feeds the theory, and its practice-led competence is connected to continuous experimentation on concrete case studies. This position requests a reflection on metropolitan knowledge and its connection with action. This connection is always crucial and it is mainly the aim for the MEMORANDUM Training. It explicitly addresses policymakers and stakeholders that "build" the Metropolis. The metropolitan communities also can find this tool – particularly due to the new type of maps proposed – empowering their capacity to participate in decision-making. The question of "action" – which refers to a more profound question on what is left to action in the age of technology – is elicited throughout the event, which is linked to action through gamification. The main training challenge is to train to a metropolitan discipline whose theory is built on the practice; in the meantime, the theory shapes the practice. In the first part of the Training, instructors will present some Metropolitan cultural heritage issues and related policies. In the second part, towards the board game case study, the approach to complexity, instead of focusing only on what we know, introduces an interest in how we know and build (or create) knowledge. The board game is based on the construction of knowledge, and the knowing agent is the participants group. Nevertheless, concerning creativity, the most salient aspect is the ability that our Training offers to multiply individual potentialities when working in concert with others.