The joinder provisions of inter partes review proceedings were instituted as a direct response to the ability of parties to settle proceedings before a final written decision is instituted. Via the joinder rules, a second Petitioner can join a previous proceeding to continue a challenge to a patent in the event that the first Petitioner settles with the Patent Owner, and even if the second Petitioner would otherwise be barred pursuant to 35 USC 315(b). This scenario played out in IPR2015-00568, Nintendo of America, Inc. and Nintendo Co., Ltd. v. Babbage Holdings, LLC involving U.S. Pat. No. 5,561,811. A key factor in all joinder cases has been the strong similarity between the petitions in the proceedings that are sought to be joined, to ensure the Board has the ability to maintain a reasonable schedule in the original proceeding.