This is a kind of trick-taking game, where the objective is to win the most points, inspired by the prisoner’s dilemma.

Players

Games of 2 players.

The play

Dealer deals 7 cards to each player. One card in played per trick, so 7 tricks are played.

In each trick, the forehand starts by announcing what color they will play (they may bluff). This color is known as the cooperation color.

Both players must now decide what color card to actually play. They may negotiate freely with each other.

When they are ready, they reveal their card at the same time, and note the points.

Players alternate to start each trick.

Points

As per the prisoner’s dilemma, the points for each trick are:

• If both players cooperate: 3 point for each.
• If both players defect: 1 points for each.
• If one player cooperates and the other defects: 5 points for the defector, 0 for the cooperator.

For a quick way to write down points: write a sequence of symbols that mean the following (one symbol per trick), according to who is writing down points:

• Tick (✓): both cooperated
• Cross (x): both defected
• Arrow pointing to the cooperator:
  • Up arrow (^): they cooperated, I defected.
  • Down arrow (v): I cooperated, they defected.

Endgame

4 rounds of 7 tricks are played. During the 5th round, after each trick, one card from the deck is revealed: if the card is a face card, they will stop playing. This is done to randomize the length of the games.

When the game ends, the player with most points wins.

Players can also boast of their cooperation with other players of the game by adding the total number of points scored by both players.

Tournament

Dilemma is best played in a tourney with many players.

Players alternate with each other, so that every player has the chance to play each other.

For a faster tourney play 1 or 2 fixed rounds per match, instead of 4. Consider keeping the randomizing endgame effect of the last round.

By the end of the tourney, the player who has accumulated the most amount of points throughout all the matches, wins.

Strategy

This game is not a clean-cut prisoner’s dilemma, because players can only play the cards they have, and sometimes their choice is forced. Playing the game as a theoretical prisoner’s dilemma may not be a winning strategy. Being able to correctly negotiate with your opponent must be part of any wining strategy.

That being said, some notes on strategy of the theoretical prisoner’s dilemma:

In the classic prisoner’s dilemma, rational players should always defect, but consider that this game is a repeated prisoner’s dilemma: if you are a compulsive defector you may not get as many points.

Especially in tourneys, you are not only playing your current match, you are playing against every player. If you want to win the tourney, every match you play must make the most amount of points for you, regardless of your opponent. This means a draw or a loss may not be bad for you if you still make a substantial amount of points.

As Robert Axelrod shows, consider “nice, forgiving and retaliatory” strategies that can either draw or loose in a single match, instead of the contrary (draw or win).