My practice research has highlighted how the play factor in architecture has been deeply embedded in our practice from the outset. Deltiology, the research methodology that I have created and developed for this PhD, has provided the two opposing, but also complementary, frames of reference of the recto and the verso to uncover this tacit knowledge. This deltiological framing has enabled me to foreground aspects of our practice such as role playing and risk taking, the breaking of the rules and conventions of design, the value of ambiguity and the uncanny, that have been latent in the design work and the structure of Boyarsky Murphy Architects. Deltiology has been deployed throughout my research and the PRS presentations to represent that which is beyond normative discourses about the practice of architecture, and to argue for the inclusion of what I have referred to as ‘everything in between’. The outcome of this research methodology is the framework Serious Play which represents a ludic model of my expanded practice and the tactics of play that I have extracted and defined through my research. This research is evidenced by reference to specific projects across the three scales of my practice: the detail, the house and the urban. With regard to the detail, I establish in the body of the work the difference between the static detail that Frascari has described in the Tell the Tale Detail and the Nomadic Detail which I argue has an independent life from its building. At the scale of the house my concept of Fitting provides a framework to intervene in an existing building or complex site with design methodologies that are flexible, semi-automatic, and which provide narrative tools that respond to the underlying psychological and emotional needs of the client. At the urban scale Urban Tactics establishes, through reference to projects of Boyarsky Murphy and examples from my teaching practice, five proactive design methodologies that are differentiated from contemporary methods of documentation and the creation of typologies that have informed research of informal and bottom up urban processes.