Federal rules permit individual district courts to enact their own local rules. Concern about the impact of local rules on the uniformity of the Federal rule system is longstanding, but there has been a proliferation of local rules in recent years. Although the ostensible purpose of local rules is not to disrupt national rule uniformity, that is often their impact. Federal district courts should not go their own way in developing civil procedures. Further, the ill-considered and unmanaged proliferation of local rules is likely to exacerbate problems in civil litigation. Varying procedures may lead to forum shopping, unnecessary costs, and widespread confusion. The trend toward localism is discussed, particularly with respect to the Civil Justice Reform Act and 1993 civil rules amendments. Reasons for the trend toward localism are considered, and the case against localism is made. The author suggests certain principles to guide Federal courts in their centralized rulemaking role and allow for controlled experimentation. 44 footnotes