Abstract: A CPU (511) of game device (50) generates bullet trajectory information when a bullet is fired at an opponent character by a player by operating a gun unit (56), and it transmits the bullet trajectory information to an echo server. The CPU (511), upon receiving the bullet trajectory information from the echo server, generates information showing a result of a determination as to whether the bullet has hit the opponent character based on the position information of a player character and the received bullet trajectory information. In a case in which a game device (50) is specified as the echo server, a game information set generated at game device (50) and a game information set received from an opponent game device are sent to opponent game devices (50) in an order in which game information sets are received.

Abstract: A CPU (511) of game device (50) generates bullet trajectory information when a bullet is fired at an opponent character by a player by operating a gun unit (56), and it transmits the bullet trajectory information to an echo server. The CPU (511), upon receiving the bullet trajectory information from the echo server, generates information showing a result of a determination as to whether the bullet has hit the opponent character based on the position information of a player character and the received bullet trajectory information. In a case in which a game device (50) is specified as the echo server, a game information set generated at game device (50) and a game information set received from an opponent game device are sent to opponent game devices (50) in an order in which game information sets are received.

Abstract: To provide a network game system for sharing, among a plurality of game machines, the positions and postures of objects associated with the game machines, while suppressing an increase in traffic in the communication network.

Abstract: To provide a network game system for enabling the player of a game to immediately find out, when a moving object, such as a bullet object or the like, contacts another object in a virtual space, from where the moving object came, by looking at the game screen image. Each of the game machines comprises a contact determination unit for determining whether or not the moving object contacts another object (402) placed in the virtual space; a contact direction acquisition unit for acquiring a contact direction of the moving object relative to the other object (402) when the contact determination unit determines that the moving object contacts the other object (402); and a contact image displaying unit for displaying an image (84) in accordance with a direction of a contact surface of the other object (402) and the contact direction at a position in the other object (402) in accordance with a contact position of the moving object.