 By “cooperating” (choosing the opaque box), each player ensures that the other gets a million dollars (and a thousand extra for defecting). By “defecting” (choosing both boxes) each player ensures that he will get thousand dollars himself (and a million more if the other cooperates). As long as \(m \gt t \gt 0\), the structure of this game is an ordinary two-player, two-move PD (and any such PD can be represented in this form). Furthermore, the arguments for “one-boxing” and “two-boxing” in a Newcomb problem are the same as the arguments for cooperating and defecting in a prisoner's dilemma where there is positive correlation between the moves of the players. Two boxing is a dominant strategy: two boxes are better than one whether the first one is full or empty. On the other hand, if the predictor is reliable, the expected payoff for one-boxing is greater than the expected payoff for two-boxing. (See Hurley (1991) and Bermúdez (2015), however, for arguments that the two puzzles are significantly different.)