61 Pa. Code § 871.18 – Governing law.

(a) In purchasing a ticket, the purchaser agrees to comply with and abide by applicable laws, this part, instructions, conditions, final decisions of the Secretary and procedures established by the Director or by the MUSL for the conduct of Powerball.
(b) Decisions made by the Secretary or the MUSL, including the declaration of prizes and the payment thereof or interpretation of this part are final and binding on players and persons making a claim in respect thereof.

This section cited in 61 Pa. Code § 871.22 (relating to changes to Powerball).