Federal courts assessing attorney-client privilege and work product doctrine claims must decide whether state law or federal law applies. Generally, state attorney-client privilege law applies in diversity cases, while federal attorney-client privilege common law applies in federal question cases.
Determining what law applies to work product issues proves much easier. As the court in Estate of Chopper v. R.J. Reynolds Tobacco Co., 195 F.R.D. 648, 650 (N.D. Iowa 2000) explained, “[t]he court applies federal law to resolve the work-product claims in this diversity case.” This simple rule rests on the fact that the work product doctrine is a creature of the federal rules themselves and therefore automatically procedural in nature.
Lawyers facing attorney-client privilege and work product doctrine issues should always sort out the law that will apply to each.