7 Pa. Code § 193.5 – Perfecta (Exacta).

(a) No Perfecta (Exacta) wagering shall be conducted without permission of the Commission. The races in which Perfecta (Exacta) type pari-mutuel wagering will be permitted shall only be those designated by the Commission and separate pools shall be established therefor.
(b) To win a Perfecta (Exacta), it is necessary for the purchaser of a Perfecta (Exacta) ticket to select in order the horse declared the winner and the horse declared to have placed in the race in which Perfecta (Exacta) type wagering is permitted. If either of the selections made by the purchaser fails to be declared to have finished in the position designated by the purchaser when purchasing the Perfecta (Exacta) ticket, then the contract is void except as hereinafter provided.
(c) Should there be a dead heat to win in a Perfecta (Exacta) race, holders of tickets combining those two horses in either order will share in the Perfecta (Exacta) payoff. Should there be a dead heat for place, holders of tickets combining the horse declared the winner with either of the horses declared to have finished in the dead heat for place shall share in the Perfecta (Exacta) payoff. In both of the aforementioned instances, the net pool shall be distributed and calculated in the same manner as a Place Pool.
(d) As a profit split to those whose combination included either the first-place betting interest to finish first or the second-place betting interest to finish second, but if there are no wagers on one of those two finishers, then
1. (1) As a single price pool to those whose combination included the one covered betting interest to finish first or second in the correct sequence, but if there are no wagers, then
  1. (i) The entire pool shall be refunded on Exacta wagers for that contest.
(e) In the event a horse or horses in the Perfecta (Exacta) should be excused by the racing officials after the horses have left the paddock for the post, or after the betting on the Perfecta (Exacta) has been closed, or should a horse or horses in the Perfecta (Exacta) be prevented from racing because of failure of the starting gate to open, the money wagered on the horse or horses so excused or prevented from racing shall be deducted from the Perfecta (Exacta) Pool and refunded to the purchaser or purchasers of tickets on the horse or horses so excused or prevented from racing.
(f) In the event only one horse finishes the race and is declared the winner, the net pool shall be distributed to holders of Perfecta (Exacta) tickets designating to win the horse declared the winner.
(g) ‘‘Fields’’ are permitted in a Perfecta (Exacta) race. If two or more horses in a Perfecta (Exacta) race are listed as the ‘‘Field’’ on totalisator tickets they shall be counted as a single selection for determining the order of finish. In the event two field entries finish in first and second place, only the one finishing first shall be deemed a winning entry for Perfecta (Exacta) purposes and the next closest non-field entry shall be deemed the second place finisher for Perfecta (Exacta) wagers. There shall be no refunds for field entries, unless all the horses listed in the field are excused before ‘‘off’’ time.