1. Prisoner Dilemma Assignment
In class, we have been learning about how to promote cooperation in an anarchic world.
One of the methods that we have come across in class is the Prisoner Dilemma. In J. Martin
Rochester’s book, Fundamental Principles of International Relations, he defines the prisoner
dilemma as a game in which the optimal, rational strategy for both players is to betray the other,
even though engaging in mutual cooperation would leave each player better off. In order to put
this method to the test, everyone in class was asked to bring their own strategy for iterated
prisoner dilemma game so that we all could compete to see who had the best strategy. I
developed my own strategy started with defection first, then my second move was cooperation,
the third move is to pick what my opponent picked for move two, the fourth move was to choose
cooperation after that the whole process repeats again. Other people in the class used some of the
strategies from Robert Axelrod’s book, The Evolution of Cooperation. Ultimately, my strategy
did not succeed against Axelrod’s Tit for Tat strategy, which ended up being the winning
strategy in the class.
Unlike Axelrod, my strategy does not have a name for it, and my strategy was not
successful. In fact my strategy is the opposite of Axelrod’s Tit for Tat strategy. In my first move,
I start with a defect. Then in my second move, I choose to cooperate. For my third move, I
choose the decision that my opponent chose in their second move. On my fourth move, I choose
to cooperate, and on the last move the whole process repeats itself. At the start of the game in
class, I scored thirty-eight points against my first Tit for Tat opponent. I found myself getting
caught in both what Axelrod calls the “sucker’s payoff” and the “Punishment for mutual
defection” (Axelrod 8). The sucker’s payoff left me with receiving zero points and the
punishment for mutual defection left me with only receiving five points. Against other strategies

2. such as people who only chose to cooperate, I found my strategy succeeding in round seven
where I scored an all-time high of eighty-one points. This occurred because since I had both
defect and cooperation as a part of my strategy I would receive five points because of the
“Temptation to defect” method and three points from the “Reward for mutual cooperation”
method (Axelrod 8). In terms of other strategies where people had a mixture of defects and
cooperation or people who had a systematic structure to their use of cooperation and defection
such as Emily, Megan, Kate, and Chloe, I did averaged about sixty points. In terms of people
who chose to defect all the time, I suffered horribly to Jerome’s strategy, which I only scored a
total of nine points. My strategy was vulnerable to receiving only sucker payoffs and punishment
for mutual defection. In total, I received five-hundred points at the end of all twelve rounds.
Axelrod’s Tit for Tat strategy is completely different from mine. According to Axelrod,
“TIT FOR TAT is the policy of cooperating on the first move and then doing whatever the other
player did on the previous move…TIT FOR TAT will defect once after each defection of the
other player. When the other player is using TIT FOR TAT, a player who always defects will get
T on the first move, and P on all subsequent moves” (Axelrod 13). Axelrod believes that there is
no strategy that is the best in the iterated prisoner dilemma game, but so far TIT FOR TAT
seems to be the best and most effective. In a series of prisoner dilemma tournament games
played on the computer, Axelrod proves how successful TIT FOR TAT is. Professional game
theorists were put to the test taking on other opponents with their own strategies, but they soon
found out how successful TIT FOR TAT was. To ensure that TIT FOR TAT was sufficient,
theorists played a second round of the tournament was played, which resulted in another TIT
FOR TAT victory. Axelrod attributes four properties that fundamentally make TIT FOR TAT the
best decision strategy. According Axelrod, the four properties are the “avoidance of unnecessary

3. conflict by cooperating as long as the other player does, provocability in the face of uncalled for
defection by the other, forgiveness after responding to a provocation, and clarity of behavior so
that the other player can adapt to your pattern” (Axelrod 20). From the end results of the
tournament, these properties demonstrate how cooperation, under suitable conditions, can
emerge in a world of egoists without the use of a central authority. Because of TIT FOR TAT,
cooperation can occur in international relations because “…individuals have a large chance to
meet again so that they have a stake in their future interaction” (Axelrod 20). The possibility of
cooperation, through the use of TIT FOR TAT, is then forged because of constant interaction and
reciprocity between countries that wouldn’t normally interact. Therefore, the reward for mutual
cooperation is beneficial for both parties rather than suckers payoff, temptation to defect, and
punishment for mutual defection.
In comparison to the winning strategy, which was TIT FOR TAT, I did terrible. Although
I did play significantly worse against those who constantly defected, I examined my moves when
playing TIT FOR TAT strategists and I see why I did terrible. In the words of Professor White, I
didn’t “maximize the amount of points per move”. On my first move against TIT FOR TAT
strategies, I received a full five points from defecting first. So I started off well but because of
the rules in TIT FOR TAT where they choose their next move based off of their opponents prior
move, I received a zero because my second move was cooperation. The common pattern of
scores per move would go five then zero and then repeat for however many moves were in the
round. Every other turn I was receiving fives, but I didn’t maximize every move because I
received zeros as well. I didn’t receive threes, which would’ve increased my total score and
round score significantly. I agree with Axelrod’s when he says that “the players cannot get out of
their dilemma by taking turns exploiting each other. This assumption means that an even chance

4. of exploitation and being exploited is not as good an outcome for a player as mutual
cooperation” (Axelrod 10). Therefore if two players continuously seek to defect, they will get
less points when they could’ve mutually cooperated and taken a chance of receiving a pair of
threes.
Over all, my strategy in the prisoner dilemma game was a failure. It didn’t stand a chance
against Axelrod’s TIT FOR TAT strategy. TIT FOR TAT made my strategy vulnerable to both
sucker’s payoff and punishment for mutual defection, which did not allow me to maximize
points every move within a round. This is because I sought to exploit my opponents more than
cooperating with them. I did receive a few fives when playing against TIT FOR TAT strategists
so in a way, my strategy slowed down the TIT FOR TAT from completely destroying me in a
round since the patterned score was fives and zeros. TIT FOR TAT remained victorious just like
in Axelrod’s article with the prisoner dilemma computer tournaments, but it ultimately helps
explain how cooperation in the real world of international relations would work because mutual
cooperation would be beneficial to both countries in the end.