Payoff matrix for an iterative prisoner’s dilemma with non-random interactions.

Following many interactions, a portion r occurs with a like-individual, and only the portion 1-r occurs with the randomly selected individual. All-C interacts with another All-C, both r and 1-r of the time the interaction generates a payoff of r(b−c)+(1−r)(b−c), with a total payoff of “r(b−c)+(1−r)(b−c)” for All-C and TFT pair of strategies. Likewise, All-C and All-D obtains r(b−c)+(1−r)( −c), and so forth.