I work on the question of what makes things complex and how to understand and manage this complexity. I have been working for decades as a systems modeler, game designer, professional trainer, facilitator and researcher to provide tools for people in all sectors to make better policies and decisions about the society and environment. I have designed and applied many simulations and role-playing games addressing the issues of complexity and sustainability. I have been working with diverse groups of scientists, businesses, NGOs and government representatives in many countries around the world. In my free time, I enjoy hiking in beautiful Polish mountains.