This Article explores the role of the Supreme Court’s Penn Central line of regulatory takings cases, from the premise that the purpose of the Penn Central doctrine is to advance fundamental fairness in an era of pervasive land use regulation. In particular, the Article focuses on whether the doctrine inherently is self-defeating, since judges are reluctant to act as “grand muftis” of zoning and planning, and hence are driven towards the type of formulaic rules that the doctrine eschews.