The most useful move in playing any game is often the decision, which games to avoid playing. This includes the avoidance of declaring war. The best encouragement to this is providing incentives for enhancing peaceful expectations. Game theory reveals the big advantage of trust, even of minimal trust, in situations that display characteristics such as those of the repeated prisoner’s dilemma game, and of the stag-hunt game. Moreover, mutual cooperation is a possible result of the repeated prisoner’s dilemma off the moves are visible during the game—at least partially. Without reputation, the players cannot make the necessary difference between the repeated and the one-time game, and then defection remains the dominant strategy. This is so since in this case each player knows that their actions will not influence the actions of the opponent. This invites institutions that promote freedom of information. Thus, game theory leads to much more peaceful, liberal, and friendly approach than some prominent experts on the theory propose.