Abstract: Provided are a program, an information processing device, and a method for controlling the information processing device that are capable of improving an interface environment for a game in which players fight a battle against each other. Provided is a watching function that allows setting of a watching right concerning a battle between players belonging to a battle group in response to a request from the terminal of a player serving as an organizer and that allows the battle between the players to be watched according to the setting content about the watching right. A watching right setting unit can set a watching right with which a battle between players belonging to the battle group cannot be watched at a terminal of a player who is neither the organizer nor the players fighting the battle but can be watched through the terminal of the player registered as an organizer.