The FRCivP govern procedure in federal court even in diversity cases in which state law governs on substantive issues. This decision holds that Washington law requiring the filing of an affidavit with a medical malpractice complaint if the plaintiff elects not to engage in mediation before filing suit does not apply to a suit filed in federal court since FRCivP 8 requires a complaint to contain only a short and plain statement of plaintiff’s claim, jurisdictional statement and explanation of the relief sought, while FRCivP 3 provides that a suit may be commenced simply by filing a Rule *-compliant complaint, nothing more is required.