In the past three decades computational processes were introduced and were widely applied in the field of architecture. This fact imposed questions about the types of strategies that architects apply during the early phase of the design process. The answer to this question became crucial as computational processes, based on algorithms, use explicit rules while in traditional ways the role of rule during the creative phase of design remains unidentified. If we want to effectively introduce computational processes into design then the role of rule in design should be identified. In this paper, I present an experiment where I examine the patterns of rules that architects use during the exploration of a design idea, from the formation of the design problem towards the design solution. Furthermore, I investigate the role that constraints play in the formulation of these design patterns of rules.