This doctoral thesis is situated within the digital design field of architecture, and is a continuation of the licentiate thesis Architectural Prototypes: Modes of Design Development and Architectural Practice, presented at the KTH School of Architecture in 2008. The doctoral thesis investigates the current status of the digital design field of architecture, and identifies a number of related discourses. Within this field, it identifies a period of formation, which in recent years has turned into a process of reformation. It contributes to this ongoing reformation by proposing two alternate areas of future practice and research within the field. A speculative approach is considered to be important for a continued mode of exploration within the field, and is suggested as away to bring new scope to the digital design field. A number of key terms from the field of science fiction studies have been investigated to support the construction of a speculative framework for further development. A strategic approach is regarded as crucial to the way new design potentials that have emerged within the digital design field to be implemented into general architectural practice, and to further inform the field itself. Key concepts have been imported from the field of strategic management in the formulation of a framework for digital design strategies. The notion of the prototype, as explored in the previous licentiate thesis, resurfaces as a prototypical approach, which could be equally employed in the speculative approach and the strategic approach. The doctoral thesis is also situated within the field of research-by-design, in the way architectural design projects have been facilitated as contextualized experiments, selected, documented and aligned in regard to terminology, and analyzed through a series of design project enquiries. / QC 20120528