This lecture constructs an operative taxonomy of the most salient methods and tools with which designers currently shape cities and open urbanised territories. Furthermore, it frames the role of the designer in the built environment as well as possible strategies and/or actions that can be taken upon encountering different projects and diverse contexts. The accompanying exhibition, organised as a series of research lines, synthesises the most significant worldwide case studies of each of the ten approaches and traces back its precedents and referents, establishing a theoretical framework and critical assessment of the different lines of work. Each 'wallpaper background' is an abstraction of a particular urban condition that relates to the underlying structure and scale of each research line. Accompanying an AA exhibition curated by Joan Busquets in collaboration with Felipe Correa. Joan Busquets is Professor of Planning Practice at Harvard Graduate School of Design; Director of Barcelona Arquitectura y Urbanismo (BAU) and former Director of Barcelonas Planning Department during the 1992 Olympics.