After dealing the players their starting hands, the player cards are divided into face down piles of equal sizes. The number of piles matches the number of Epidemic cards used, based on difficulty:
- Introductory: 4 Epidemic cards
- Standard: 5 Epidemic cards
- Heroic: 6 Epidemic cards
One Epidemic card is shuffled into each pile. Then these piles are stacked to form the Player Deck.