This chapter assesses the role of planning in the design of governance strategies. Enthusiasm for large-scale planning—also known as overall, comprehensive, long-term, economic, or social planning—boomed and collapsed in twentieth century. At the start of that century, progressive reformers seized on planning as the remedy for the United States' social and economic woes. By the end of the twentieth century, enthusiasm for large-scale planning had collapsed. Plans could be made, but they were unlikely to be obeyed, and even if they were obeyed, they were unlikely to work as predicted. The chapter then explains that leaders should make plans while being realistic about the limits of planning. It is necessary to exercise foresight, set priorities, and design policies that seem likely to accomplish those priorities. Simply by doing this, leaders encourage coordination among individuals and businesses, through conversation about goals and tactics. Neither is imperfect knowledge a total barrier to planning. There is no “law” of unintended consequences: it is not inevitable that government actions will produce entirely unexpected results. The more appropriate stance is modesty about what is known and what can be achieved. Plans that launch big schemes on brittle assumptions are more likely to fail. Plans that proceed more tentatively, that allow room for testing, learning, and adjustment, are less likely to collapse in the face of unexpected results.