Here are the rules from Discraft.
Players are required to use the player package discs, and only these discs. If a disc is lost, the player has the option of using the second disc from the package. Only one throw per player per hole. All players should have their own scorecards and mark "A" for aces (a hole-in-one) and "M" for holes on which they hit metal.
After all players in the group have thrown, discs are picked up and the group moves directly to the next tee. Players keep their scorecards for round two, using the next line on the card to record the round.
The player with the most aces after 36 holes is declared the winner. In case of ties, the number of metal hits is used as a tie breaker. If a tie persists, a closest to the pin contest is then used to determine the event winner.