Werewolf is a terrific game, made all the better by the fact that it’s absolutely free. Before each game you randomly distribute Identity cards — one player will be the Moderator, one player will be the Seer, two players will be Werewolves, and all the rest will be Villagers. Players identities are kept secret, and you can never show anyone else your card.
The game alternates between night and day. At night, all players close their eyes and then the Moderator says “Werewolves, open your eyes”. The two players with the Werewolf cards open their eyes and silently agree upon another player to kill. After they have decided and communicated their pick to the Moderator, they again close their eyes and the Moderator says “Seer, open your eyes”. The Seer then points at another player, and the Moderator indicates whether the selected player is or is not a Werewolf. Then everyone opens their eyes and day begins.
At daybreak the person killed by the Werewolves immediately turns his card faceup and plays no further part in the game. The rest of the day is simple: all the living players must now decide who to lynch. As soon as a majority of players give the thumbs down to someone, the targeted player is killed: he flips his card faceup and is out. This continues until the Villiagers win by lynching both Werewolves, or until the Werewolves when the number of Villiagers is equal to the number of Werewolves (at which point the Werewolves rise up and openly slaughter the remainders).
A very simple game, but exceptionally tricky to play. The tension comes from two angles: on the one hand, you never really know who any of the other players are, so picking someone to lynch is tough; on the other, no one really knows who you are, so even if your innocent you may find yourself the target of mob rule. As a Seer you may know the Identities of a few people, but your job is just as difficult: you have to get people to lynch the Werewolves without exposing yourself (and thereby certainly getting killed the following night). And even if you do expose yourself (“I’m the Seer, and I know for a fact that he is a Werewolf!”), that doesn’t mean the Villagers will necessarily believe you, since making this very statement is favorite tactic by the Werewolves.
You can play Werewolf with just about any set of cards, or even make your own. When playing with standard playing cards, we use the Ace of Spades for the Moderator, the King of Clubs for the Seer, the Jokers (or the red Jacks) for the Werewolves and then an assortment of cards ranked 2-9 for the Villigers.