Policy design, whether conceptualized as a verb referring to the process of formulating policy ideas, or as a noun describing the logic through which policy intends to achieve its objectives, remains relatively uncharted territory. This paper reviews what we know about how policy designs emerge, and identifies the kinds of biases and weaknesses that are introduced into designs by the decision heuristics employed. Theories of policy invention and expert decision-making suggest that individuals search through large amounts of relevant information stored in memory, reason by analogies, make comparisons, and either copy or simulate patterns of information. Policy scholars may contribute to improved policy design by making more explicit the biases introduced through reliance on decision heuristics, and by suggesting a more formal, self conscious search and selection process that enables designers to be more discriminating when they pinch policy ideas from other contexts. To perform this task, comparative policy analysis is needed in which common elements that exist in virtually all policies are identified and the underlying structural logic of the policies is made explicit. In this paper we set forth generic elements found in policies, describe and compare some of the more common design patterns, and discuss the circumstances where these may be inappropriately copied or borrowed, thereby thwarting the effectiveness of the policy.