Play Contexts and Generic Prisoner’s Dilemma

There are four possible round outcomes:

• Mutual cooperation: \((C, C)\)

• Defection: \((C, D)\) or \((D, C)\)

• Mutual defection: \((D, D)\)

Each of these corresponds to one particular set of payoffs in the following generic Prisoner’s dilemma:

	Cooperate	Defect
Cooperate	(R,R)	(S,T)
Defect	(T,S)	(P,P)

For the above to constitute a Prisoner’s dilemma, the following must hold: \(T>R>P>S\).

These payoffs are commonly referred to as:

• \(R\): the Reward payoff (default value in the library: 3)

• \(P\): the Punishment payoff (default value in the library: 1)

• \(S\): the Sucker payoff (default value in the library: 0)

• \(T\): the Temptation payoff (default value in the library: 5)

A particular Prisoner’s Dilemma is often described by the 4-tuple: \((R, P, S, T)\):

>>> import axelrod
>>> axelrod.game.DefaultGame.RPST()
(3, 1, 0, 5)