These Rules amend the Armed Forces (Court Martial) Rules 2009 (S.I. 2009/2041). Rule 29 of those rules require a minimum of five lay members to sit in the Court Martial in proceedings described in that rule. Rules 3 and 4 provide so that rule 29 does not apply to sentencing or variation proceedings where a sole defendant or all co-defendants have entered a guilty plea before the commencement of trial proceedings. In such proceedings section 155(1) of the Armed Forces Act 2006 (c. 52) applies so that there must be at least three, but not more than five, lay members.