From the back of the "Face the Hydra" challenge deck, "This box contains sixty challenge cards and an instructional playmat. To play against this challenge deck, each player must have a Magic: The Gathering deck." The challenge deck allows 1 person or multiple people working together to play against a programmed deck. The cards in this deck are not designed to be mixed with standard M:tG cards and have a distinct back. Players play their cards against this deck before running out of health. The challenge deck does not play cards normally. Each turn a card is drawn and its effect is applied immediately. When playing against the Hydra deck, Hydra Head cards are placed in play. The player(s) can attack 1 head each turn. If enough damage is done to destroy a head, then 2 cards are drawn and if any are head cards, they are placed in play. The game continues until either there are no heads in play or the player runs out of health. Each turn, each Hydra head automatically damages the player.