Virtually every lawyer is familiar with the rules versus standards trade-off. Rules provide clearer guidance but sometimes produce bad results (i.e. “loopholes”). Standards provide more flexibility but at the cost of diminishing ex ante notice. For a high level court such as the Supreme Court, the degree of specificity with which to announce a doctrine—and, correspondingly, the amount of discretion to leave to lower courts to develop the doctrine in future cases—typically involves the basic tradeoff between ex ante notice and ex post flexibility.