 

Player 2  
Cooperate  Defect  
Player  Cooperate 


1  Defect  

Each player (prisoner) can either defect (confess) or cooperate (don't confess) to try to maximize his own payoff (low prison term).
For the payoff matrix to qualify as a prisoner's dilemma game, it must be true that
T
> R
> P
> S
.
T
= "Temptation to cheat" payoff
R
= "Reward for mutual cooperation" payoff
P
= "Punishment for mutual defection" payoff
S
= "Sucker's" payoff