In recent years, games provided to mobile terminals via communication networks have included “battle games.” In such a battle game, multiple players who may each operate a mobile terminal cooperatively fight against an enemy character. In a multiplayer battle game, a special skill of a character may be activated, and heavy damage may be done to the enemy character, or a friend character in the same group may be affected (for example, the skill may cause recovery of a hit point (HP) of a friend character). A special skill may be activated in response to an input operation of one player in the group.
For example, Japanese Unexamined Patent Application Publication No. 2014-233637 describes a battle game in which a raid battle is performed. In the raid battle, a player battles against an enemy character in cooperation with other players. In the raid battle in the multiplayer battle game, if the amount of points given to a specific player from the other players is greater than or equal to a predetermined value, an attack having a power corresponding to the point is made to the enemy character in response to an instruction from the specific player.
However, since a special skill is activated in response to an input operation of only one player in the multiplayer battle game in the related art, it is not possible to reflect the intentions of cooperation or agreement of the other players to the activation of the special skill in the magnitude of the effect of the special skill. In addition, for example, the players individually enhance their skills in order to vary the magnitude of the effect of the special skill. Accordingly, an individual player has no option but to make an effort in order to greatly vary the effect of the skill. No mechanism is provided in which an individual player greatly varies the effect of the skill in cooperation with the other players in the same group.