= 0 pts
= 1 pts
= 3 pts
= 5 pts
Tell me more about this graphic Ok, got it
Each vertical bar represents one round in the iterated Prisoners Dilemma.
Its color tells you the result of the round:
Result You scored Opponent scored
Mutual cooperation 3 3
Mutual defection 1 1
Greed 5 0
Sucker 0 5
Your total score for the 120-round game is shown at top left. The parenthetical shows you what agent acted as your "opponent" and its total score. Remember you aren't trying to beat the opponent, just trying to maximize your own score.
... or upload your code (accepts Java or Python)
How to play
The game is 120 rounds. Each round you pick a row in this table, and the other player picks a column:  
Cooperate 3 (3) 0 (5)
Defect 5 (0) 1 (1)

You are awarded the points in bold, and the other player gets the points in parentheses.

Your goal is to get as many points as you can. The other player's score doesn't affect you, except that the other player will strategize to get as many points as possible too.

Please see our Overview for more information.


The agent (self) has an actor field. Make your move by calling one of these functions on the actor:
actor.act(action) where action is COOPERATE or DEFECT

Those functions each return an object result for the round, with these fields:
myAction - action you picked
myPayoff - points you got
otherPlayerAction - action opponent picked
otherPlayerPayoff - points opponent got

See full API for more info.


Our present Python example is Tit For Tat, a short routine which cooperates on the first move, and thereafter does what the opponent did on the previous move.

If Tit For Tat source code is not already visible in the editor, click here to load it.