A discussion of the Ruby simulation framework for the Repeated Prisoner's Dilemma I created as part of my Masters thesis "An Investigation of Retaliation and Reconciliation Conventions in the Repeated Prisoners Dilemma"

1. Game Theory and Simulation in Ruby Presenter: Matt Pattison Based on Masters thesis: ‘ An Investigation of Retaliation and Reconciliation Conventions in the Repeated Prisoner’s Dilemma’

4. Game theory is not just about ‘games’, but ‘games’ are a good place to start Gonzales is playing Federer, who has come in to the net, and hit the ball to Gonzalez’s forehand. Should Gonzalez return the ball down the line with his powerful forehand, whip the ball cross-court or risk a lob. Federer vs. Gonzalez

5. How often should Gonzalez go cross court (CC), down the line (DL), or lob (Lob)? First we need to look at the probabilites of success for Gonzalez:

6. Then we can determine the correct proportions from a best response graph

7. Game theory is not just about ‘games’, but…

8. Game theory is not just about ‘games’, but… Player balance in Starcraft: It is important that no strategies are dominant or dominated. Therefore available strategies for different players usually have payoffs that resemble Rock-Scissors-Paper

9. Archers-Cavalry-Pikemen Rock-Paper-Scissors equivalent game-balancing Actual dominance relationships from ‘Age of Kings’

10. The battle of the local pizza joints Should each pizza joint price High, Medium, or Low?

11. The battle of the pizza joints cont... Pricing Low is a dominated strategy What we are left with is…

12. The Prisoner’s dilemma Using Greed (G) and Fear (F) factors * Greed factor represents benefit from exploiting opponent. * Fear factor represents disbenefit from cooperating and being exploited

14. Nash equilibrium Strategies that are best responses to each other

17. The repeated prisoner’s dilemma See the example…

19. Strategy state machines See the code… Example of DSL

20. R1P2

21. Finite Markov Chain strategy pairs

22. R1P2 vs R1P2

23. Questions?