1. A computer program product, comprising: a program code module which controls an action of a player's character in a battle between the player's character and an enemy character; a program code module which controls an action of the enemy character in the battle; and a program code module which stores, in a first point storage, a current value of a first point indicative of a power required for achieving a specific ability in the battle and manages an increase and decrease in the current value of the first point, wherein the first point stored in the first point storage is shared by the player's character and the enemy character, and when the player's character exercises the specific ability or the enemy character exercises the specific ability, said program code module which manages the change in the current value of the first point subtracts a value required for the exercise of the specific ability, from the current value of the first point.