These dilemmas are examples of games in which both players share the same preferences. These games are known as symmetric games. In these games, neither player has a privileged position. In this sense, they can often model the real world.
|Cooperate  ||Defect  |
|Cooperate  ||1, 1||0, 3|
|Defect||3, 0||2, 2|
Each player does better defecting no matter what his partner does. Unlike the prisoner's dilemma though, it is better for them to both defect than to both cooperate. This is called deadlock because the two players will decide not to cooperate. This situation sometimes arises when two countries do not want to disarm so fail to reach arms control agreements.
In early societies, people formed alliances to hunt deer. If even one person in the group did not help with the hunt, the deer would be lost. The hunters were sometimes tempted to leave the hunt by seeing rabbits, but they preferred deer to rabbit. However, only one person was needed to catch a rabbit. From a game theory perspective, the best strategy is to hunt the deer, but people may decide to hunt the rabbit because they believe others may defect from the hunt also.
Countries face the same dilemma in situations involving nuclear weapons. Each country generally believes that the world would be better if no countries possessed nuclear weapons. However, the temptation to build up a nuclear arsenal arises because each country is afraid that other countries may stash nuclear warheads and undermine international security.