This chapter looks at the U.S. Supreme Court’s adoption of a radical new pleading standard as an example of dynamism in U.S. law. The Federal Rules of Civil Procedure provide for notice pleading and were liberally construed for nearly 70 years after initial adoption. Even though a rule-making procedure supervised by the U.S. Supreme Court was available to make direct changes to the pleading rule, the U.S. Supreme Court took a common law approach and adopted a new standard judicially rather than administratively. This shows a substantial role for the U.S. Supreme Court in directly making procedural law for the Federal courts. The lower courts, however, have moderated the new standard through the exercise of their independence and judicial powers of interpretation. Thus, dynamism is reflected by the U.S. Supreme Court’s judicial adoption of a new standard and by the lower courts reaction to that standard.