Idaho Rules of Evidence Rule 606. Competency of Juror as Witness.
(a) At the trial. A member of the jury may not testify as a witness before that jury in the trial of the case in which the person is sitting as a juror. If a juror is called so to testify, the opposing party shall be afforded an opportunity to object out of the presence of the jury.
(b) Inquiry to validity of verdict or indictment. Upon an inquiry into the validity of a verdict or indictment, a juror may not testify as to any matter or statement occurring during the course of the jury's deliberations or to the effect of anything upon the juror's or any other juror's mind or emotions as influencing the juror to assent to or dissent from the verdict or indictment or concerning the juror's mental processes in connection therewith, nor may a juror's affidavit or evidence of any statement by the juror concerning a matter about which the juror would be precluded from testifying be received for these purposes, but a juror may testify on the questions whether extraneous prejudicial information was improperly brought to the jury's attention or whether any outside influence was improperly brought to bear upon any juror and may be questioned about or may execute an affidavit on the issue of whether or not the jury determined any issue by resort to chance.
(Adopted January 8, 1985, effective July 1, 1985.)