The business judgment rule is corporate law\u27s central doctrine, pervasively affecting the roles of directors, officers, and controlling shareholders. Increasingly, moreover, versions of the business judgment rule are found in the law governing the other types of business organizations, ranging from such common forms as the general partnership to such unusual ones as the reciprocal insurance exchange. Yet, curiously, there is relatively little agreement as to either the theoretical underpinnings of or policy justification for the rule. This gap in our understanding has important doctrinal implications. As this paper demonstrates, a string of recent decisions by the Delaware supreme court based on a misconception of the business judgment r...