Rule 601.
Every person is competent to be a witness unless these rules provide otherwise. But in a civil case, state law governs the witness’s competency regarding a claim or defense for which state law supplies the rule of decision.
([Pub. L. 93–595, § 1], Jan. 2, 1975, [88 Stat. 1934]; amended Apr. 26, 2011, eff. Dec. 1, 2011.)