In a virtual three-dimensional space, at least multiple player characters and a movable special object exist. The multiple player characters move in the virtual three-dimensional space according to operations of each player. The special object can be moved in the virtual three-dimensional space according to operations of each player character. An image, which is perspective-transformed in a state that a visual axis of a virtual camera is directed to the direction of the special object, is displayed as a game screen. An area, which is within a predetermined distance from the special object, is fixed as a safety zone. Hit points of the player characters, which are within the safety zone, do not decrease. However, hit points of the player characters, which are outside the safety zone, decrease.