Deadfall is a gambling / bluffing game. Players ante one coin to begin and start with a hand of six cards. Everyone plays one card, and the lowest of these will go first.
On your turn you may either play a new card face up or call one of your opponents. When you play a card, you are trying not to play the last card of that rank. For example, if you play a 5, you are declaring that someone's hand still contains a 5. If you have one, you know you're safe. If not, you're making an educated guess.
A call ends the hand. When you call another player, you are saying that they were wrong when they played their last card, and there are no more cards of that rank left in anyone's hand. If the caller is right, she wins the pot, plus a penalty equal to the rank of the card, paid by the called player. (For example, 7 coins for calling a 7.) If the caller is wrong, the called player wins the pot, and he wins the same penalty from the caller.
There are two ways to get ahead in Deadfall: You can catch people when they play the wrong cards, and you can trick others into calling you when you're safe.