Game system for occupying a team position in a game area disposed between a plurality of teams

[0002] 1. Field of the Invention

[0003] The present invention relates to a game system, and more particularly to a novel game system which is a sort of position occupying game like a game of “go” but differs essentially from an indoor game like “go” in that the body of a player is moved, and which further differs from a scramble type position occupying game such as a soccer game and a rugby game, in that players all move in all directions within an extensive game area.

[0004] 2. Description of the Related Art

[0005] Play (including games) for children has an important part in learning rules and manners necessary for life in society, and in addition, play requiring functional movement of the body is considered useful in that reflexes, muscular strength, and sustaining power are developed. However, the main current of play has recently been shifted to indoor games like television games. Particularly, there is fear for sound upbringing of young people.

[0006] Directing attention to outdoor play requiring functional movement of the body in view of such a social background, most play falls under the category of a sport. Of people having a tendency to stay indoors, young people watch sports, but it is regrettable that they do not positively take part in sports. The first reason is that every possible sport requires troublesome, tedious practice to one degree or another. The second reason is that many of the lovers of television games have had a mental habit of entering into a virtual world on the screen. Unless a motion-type game having excitement of a virtual world without requiring practice is developed, achievement of social needs for upbringing of young people through outdoor sports will be fairly difficult.

[0007] As described above, the conventional game systems represented by television games have the disadvantage that they are unsuitable for the relation with people and the growth and health promotion of the body, because they are exclusively employed indoors.

[0008] The present invention has been made in view of the circumstances mentioned above. Accordingly, it is the primary object of the present invention to provide a novel game system which is capable of having excitement of a virtual world without requiring practice, also causing a player to move in all directions within an extensive game area in cooperation with other players, and making a contribution to the relation with people and the growth and health promotion of the body.

[0009] To achieve this end, there is provided a game system comprising:

[0010] a single referee machine; and

[0011] a single parent machine and a single flag machine provided in each team;

[0012] wherein the referee machine collects needed information from all the parent machines and also transmits necessary game information to the parent machine of each team;

[0013] wherein the parent machine generates information to command movement of a player of the self-team by employing both information acquired from the flag machine of the self-team and the information transmitted from the referee machine and then transmits the generated information to the player, and also transmits the information acquired from the flag machine of the self-team, to the referee machine; and

[0014] wherein the flag machine specifies spot coordinate information from the movement of the player and also transmits the spot coordinate information to the parent machine of the self-team.

[0015] According to the present invention, a game requiring movement of a player can be performed. That is, a player sets an arbitrary spot within an extensive game area in cooperation with the other players of the self-team and moves within the game area. Furthermore, the progress of the game is made in a virtual game area. This can interest people being accustomed to indoor games such as television games, particularly young people. And young people are urged to join the game. Therefore, the game system of the present invention is capable of contributing to the relation with people and the growth and health promotion of the body.

[0016] The present invention will be described in further detail with reference to the accompanying drawings wherein:

[0017] FIG. 1 is a perspective view showing a game system constructed according to an embodiment of the present invention;

[0018] FIG. 2 is a block diagram showing the flag machine of FIG. 1;

[0019] FIG. 3 is a perspective view showing a referee machine or parent machine;

[0020] FIG. 4 is a block diagram of the referee machine or parent machine shown in FIG. 3;

[0021] FIG. 5 is a diagram showing a game area;

[0022] FIGS. 6A and 6B are diagrams showing how an area is acquired in the first round of a game;

[0023] FIGS. 7A and 7B are diagrams showing how an area is acquired in the second round and the rounds thereafter;

[0024] FIG. 8 is a diagram showing the state in which an area acquired by one team partially overlaps that of the other team;

[0025] FIG. 9A is a diagram showing the display screen of one team, on which an area acquired by the one team is displayed but an area acquired by the other team is not displayed;

[0026] FIG. 9B is a diagram showing the display screen of the other team, only an area acquired by the other team having been displayed;

[0027] FIG. 10 is a diagram showing the progress of a game displayed on the screen of the referee machine;

[0028] FIG. 11 is a diagram showing the progress of the game displayed on the screen of the parent machine of the A-team;

[0029] FIG. 12 is a diagram showing the progress of the game displayed on the screen of the parent machine of the B-team; and

[0030] FIG. 13 is a diagram showing another game rule suitable for the embodiment of the present invention shown in FIG. 1.

[0031] A preferred embodiment of a game system suitable for a “position occupying game” will hereinafter be described in detail with reference to the drawings.

[0032] In the game system of the preferred embodiment, at least two camps (also called teams) play a position occupying game. The progress of the game is all made electronically by both a referee machine, and a parent machine distributed to each team. Players send necessary information to the referee machine or parent machine by manipulating an electronic device called a flag machine, and also act according to a command given by the referee machine or parent machine and pursuant to rules. That is, a game area virtually made in the interiors of the referee machine and the parent machine (hereinafter referred to as a virtual game area) is replaced with a game area having actuality (hereinafter referred to as an actual game area), and the position occupying game is enjoyed.

[0033] In the game system of the preferred embodiment, the game participants are divided into two groups, excluding a referee part. In the preferred embodiment, one group is called an A-team and another group is called a B-team. The referee part acquires information necessary for the game progress from the parent machines of both teams, while grasping the war situations of both teams, using the aforementioned referee machine. The referee part also selects necessary information and sends it to the parent machines of both teams. The position of the referee part is suitably selected within the radio communication range between itself and the parent machines of both teams. On the other hand, members of each team are players who actually move, excluding at least a person who manipulates the parent machine. Each player with a flag machine and a portable radio machine moves in all directions through the extensive, actual game area spreading between the bases of both teams, and acquires a region within the actual game area pursuant to predetermined rules. A team which acquires more areas than an opponent team within a game time, or a team which first reaches the camp of an opponent team, wins the game.

[0034] In FIG. 1, reference numeral 1 denotes a flag machine and reference numeral 2 denotes a portable radio machine. The flag machine 1 is equipped with a global positioning system (GPS) antenna 4 for receiving a radio wave from a GPS satellite 3; a transmitting-receiving antenna 5 for receiving a radio wave from a portable radio machine 2 of a self-team (hereinafter referred to as a self-radio machine) or a parent machine (not shown) of the self-team (hereinafter referred to as a self-parent machine), and transmitting a radio wave to the self-radio-machine 2 or the self-parent machine; a main body portion 7 incorporating an electric unit 6 which has a GPS position measuring function and a data transmitting-receiving function; and a proximal portion 9 for supporting the main body portion 7 through a stay 8. The portable radio machine 2 is equipped with an antenna 10 for receiving a command, relayed through the electronic unit 6 of the flag machine 1, and transmitted from the self-parent machine (e.g., a voice synthesis command, or a voice command from the operator of the self-parent machine), and for transmitting a response. The portable radio machine 2 is also equipped with an electronic circuit section 11 having a loudspeaker function and a response function (a voice response or a switch operation response) for the aforementioned command.

[0035] The flag machine 1 is used for inputting information on an arbitrary spot in the actual game area (latitude-longitude information) to the virtual game area. That is, if the flag machine 1 being operated is placed on the ground, a switch (not shown) in the proximal portion 9 is switched on by the dead weight of the flag machine 1. In response to this, the coordinate information at the spot (measured by the use of a radio wave from the GPS satellite 3) is transmitted from the antenna 5 to the self-parent machine. The coordinate information is further transmitted from the self-parent machine to the referee machine.

[0036] The actual game area, incidentally, includes not only flat ground but a large number of obstacle zones such as sharp slopes (a cliff, etc.), damp ground, ponds, rivers, etc. It is desirable that the flag machine 1 be constructed so that even in such obstacles zones, it can perform the measurement of spot information and the transmission of information without difficulty. The stay 8, for example, can be constructed to be freely flexible so that the directivity of the GPS antenna 4 or transmitting-receiving antenna 5 is obtained even at a sharp slope. It is also desirable that the flag machine 1 float on water. Furthermore, it is desirable in consideration of water depression or use in rainy weather that it prevent an entrance of water.

[0037] The role of the portable radio machine 2, as described above, amplifies a command (voice) given by the self-parent machine and sends out the response to the self-parent machine. However, it is also possible to allot this role to the flag machine 1. That is, the electronic unit 6 of the flag machine 1 may have both the function of amplifying a command (voice) sent from the self-parent machine and the function of sending back the response to the self-parent machine. If done in this manner, the portable radio machine 2 can be eliminated. However, the flag machine 1 has weight of some magnitude, and carrying it is heavy and is a burden on players. In this embodiment, the portable radio machine 2 has the function of receiving a command and the function of transmitting a response. The portable radio machine 2 weighs much less than the flag machine 1, which enables a player to move around more easily and enhances the smooth progress of the game. In this respect, the portable machine 2 is indispensable to the game. It is preferable that the communications distance between the flag machine 1 and the portable radio machine 2 be as short as possible (about 20 to 30 m). This prevents an unjustifiable act, which disturbs the progress of a game, such as far movement of a player with the portable radio machine 2 from the flag machine 1 to scout an enemy team.

[0038] FIG. 2 shows the construction of the flag machine 1. The flag machine 1, in addition to having the GPS antenna 4 and the transmitting-receiving antenna 5, is further equipped with a GPS receiver 12, a transmitter-receiver 13, a switch input section 14, an installation detecting section 15, a read-only memory (ROM) 16, a random access memory (RAM) 17, a display unit 18, a voice output unit 19, and a control section 20. Each section, excluding the GPS antenna 4, the transmitting-receiving antenna 5, and the installation detecting section 15, is mounted in the electronic unit 16 shown in FIG. 1, and the installation detecting section 15 is incorporated into the proximal portion 9 shown in FIG. 1. The essential section (particularly the GPS position-measuring section) of the flag machine 1 is replaceable with a commercially-available car navigation unit. The section, including the control section 20, the ROM 16, the RAM 17, the display unit 18, and the voice output unit 19, is also replaceable with a computer applied product such as a game machine, a personal computer, etc. However, since those sections are carried by a player, it is desirable to design them exclusively from the standpoint of weight, size, design, etc.

[0039] The GPS antenna 4 is, for example, a mirostrip patch antenna, employing a Teflon board, which has semispherical directivity, for receiving a right-handed polarized wave signal of about 1.5 MHz which is sent from the GPS satellite 3. The GPS receiver 12 receives and demodulates position-measuring radio waves sent from a plurality of GPS satellites, through the GPS antenna 4, and also calculates the current position information of the flag machine 1 (e.g., latitude-longitude information), based on the demodulated signal. Furthermore, the GPS receiver 12 outputs the calculated current position information to the control section 20. The GPS is a position measuring system utilizing artificial satellites, and receives radio waves from three or more satellites of a total of 24 satellites disposed four by four in six earth-circling orbits, also calculates the distance between the receiving spot and each satellite from the arrival time, and measures the position of the receiving spot (in the case of 3 satellites, a two-dimensional position, latitude and longitude).

[0040] The transmitting-receiving antenna 5 is used for receiving information transmitted from the self-radio machine or self-parent machine, and transmitting information to the self-radio machine or self-parent machine. The transmitting-receiving antenna 5 employs, for example, a non-directional antenna. The transmitter-receiver 13 demodulates the information from the self-parent machine, received through the transmitting-receiving antenna 5, and outputs information for game progress to the control section 20. In addition, the transmitter-receiver 13 modulates information (particularly the positional information of the flag machine 1) which is sent from the control section 20 to the self-parent machine, also transmits the modulated information through the transmitting-receiving antenna 5, and relays information between the self-parent machine and the self-radio machine.

[0041] The control section 20 is constructed, for example, of a microcomputer that is operated by manipulating the switch input section 14. This microcomputer controls the general operation of the flag machine 1 by loading the program stored in the ROM 16 into the RAM 17 and executing the program. The microcomputer also receives the positional information from the GPS receiver 20, responds to the switching action of the installation detecting section 15 that is made on when the flag machine 15 is placed on the ground, and realizes a “positional-information notification function of sending out the positional information at that time to the self-parent machine. Note that these functions may be performed in a hardware manner.

[0042] The display unit 18 is used to monitor the operation of the flag machine 1 or display the current position. The voice output unit 19 is used to amplify and output a command sent from the self-parent machine. The self-radio machine also has the function of amplifying and outputting a command sent from the self-parent machine. Therefore, if the flag machine 1 communicates with the self-parent machine by use of this self-radio machine, the voice output unit 19 of the flag machine 1 can be eliminated.

[0043] As previously described, a single referee machine is employed and a single parent machine is employed in each team. That is, the game requires a single referee machine and two parent machines. The referee machine and the parent machine, as shown in FIG. 3, can be constructed with a general-purpose personal computer 30, a communication modem 31, and a radio communication unit 32 with a data transfer function (which is not limited to the portable telephone shown in the figure). The referee machine and the parent machine are the same in appearance. They are differentiated from each other by programs that are executed. That is, if a program for the referee machine is executed, the personal computer 30 is used as the referee machine. If a program for the parent machine is executed, the personal computer 30 is used as the parent machine.

[0044] The referee machine and the parent machine, in addition to having the functions that the personal computer 30 has (e.g., a display function, a file managing function, a data input-output function, a printing function, etc.), further have a function of recognizing the communication modem 31.

[0045] The referee machine, in addition to having all the functions necessary for game progress, that is, a function of identifying the parent machine or flag machine, a function of receiving information transmitted from the parent machine (and also receiving information transmitted from the flag machine through the parent machine), and a function of selecting necessary information and transferring the information to the parent machine, further has a variety of functions for generation of the virtual game area, game mediation, decision of victory or defeat, management of a game time, evaluation of game results, etc.

[0046] The parent machine has only the functions, necessary for the action of the self-team, among the functions necessary for game progress. In other words, the parent machine has only the function of completely grasping the movement of the self-team and the function of grasping part of the movement of the opponent team, among the functions that the referee machine has. Since the parent machine can grasp only part of the movement of the opponent team, the operator of the parent machine needs to predict the strategy and intention of the opponent team from a small amount of information to control the movement of the players of the self-team. A difference in skill occurs between the operators of the parent machines and increases the excitement of the game.

[0047] FIG. 4 shows a block diagram of the referee machine or parent machine (hereinafter represented with the referee machine). In the figure, the referee machine R is equipped with a transmitting-receiving antenna 33, a transmitter-receiver 34, a switch input section 35, a ROM 36, a RAM 37, a display unit 38, a voice output unit 39, and a control section 40. If it is constructed as shown in FIG. 3, the referee machine R is further equipped with a hard disk, a CD-ROM drive, a PC card slot, etc. The referee machine R functions as the referee machine or the parent machine by executing a referee-machine program or a parent-machine program, installed in the hard disk. Note that the transmitting-receiving antenna 33 and transmitter-receiver 34 in FIG. 4 correspond to the communication modem 31 and portable radio communication unit 32 of FIG. 3. The switch input section 35 in FIG. 4 corresponds to the input devices (keyboard, mouse, pointing device, etc.,) of the personal computer 30 of FIG. 3.

[0048] The control section 40 realizes the functions required of the referee machine or parent machine by executing the referee-machine program or parent-machine program. However, there is a great difference in information transmission between the referee machine and the parent machine. That is, the referee machine can transmit and receive information between itself and all the parent machines, while the parent machine can transmit and receive information only between itself and the referee machine. The management of such information transmission can be realized if a sender-identifying code is contained in information so that the parent machine can receive only the information sent from the referee machine. Furthermore, the information that is transmitted from the referee machine to the parent machine is limited to information necessary for the team to which that parent machine belongs. In the case where information for the opponent team is transmitted in error, the progress of the game is disturbed. The management of receivers to which information is transmitted can also be realized by containing a destination-identifying code into information.

[0049] FIG. 5 illustrates an example of an actual game area or virtual game area. In the figure, a position 51 for the A-team (hereinafter referred to as an A-team position) and a position 52 for the B-team (hereinafter referred to as a B-team position) are disposed to face each other across a game area 50. The referee machine R is disposed in a proper place between the A-team position 51 and the B-team position 52. The parent machine M_afor the A-team is disposed in a proper place within the A-team position 51. Similarly, the parent machine M_bfor the B-team is disposed in a proper place within the B-team position 52. Furthermore, the flag machine F_afor the A-team is disposed near the parent machine M_a, and the flag machine F_bfor the B-team is disposed near the parent machine M_b.

[0050] The declaration of the setting of a camp by each team is made by placing the flag machine F_aor F_bon a proper spot, then transmitting the coordination information on that spot to the parent machine M_aor M_band the referee machine R, and setting a proper spot 53aor 53bonto an imaginary line L_aor L_bpassing through the installation point of the flag machine F_aor F_b. In the illustrated example, the A-team position 51 is disposed above the imaginary line La, and the B-team position 52 is disposed below the imaginary line L_b.

[0051] In FIG. 5, the positions of both teams (51, 52), the positions of the parent machines (Ma, Mb), the positions of the flag machines (F_a, F_b), etc., are shown. However, these should be grasped only by the referee machine R. The parent machines (M_a, M_b) of both teams should grasp only minimum information necessary for game progress, that is, all information related to the self-team and the position of the opponent team. Therefore, only the positions of M_a, F_aand Lb are displayed on the screen of the parent machine M_aof the A-team. Similarly, only the positions of M_b, F_b, and La are displayed on the screen of the parent machine M_bof the B-team.

[0052] The first condition for determining the victory or defeat of the game is that one team sets the flag machine within the position of another team. The second condition is to acquire (or occupy) as many areas as possible, within the game area 50 pursuant to predetermined game rules. The first condition is prior to the second condition. That is, the second condition is employed when the first condition is not met.

[0053] The configuration of an area that can be acquired in one round of the game is limited to a triangle. The kind of the triangle does not matter if it has three vertexes. The flag machine is set at each vertex, and the positional coordinate information at the vertex is transmitted to the parent machine and the referee machine. FIG. 6 shows one round of the game. The flag machine is set at the first vertex F1, and the positional coordinate information is transmitted. Then, the flag machine is moved and set at a vertex F2, and the positional coordinate information is transmitted. Next, the flag machine is moved and set at a vertex F3, and the positional coordinate information is transmitted. In this manner, one round of the game ends. As shown in FIG. 6B, the area D1 enclosed by the three sides 55 to 57 between the vertexes F1 to F3 is an area acquired by the team having the flag machine.

[0054] In the second round and the rounds thereafter, the operation of setting the flag machine is performed only twice, because the flag machine is moved from one of the vertexes of the triangle acquired in the previous round. That is, in FIG. 7, the vertex F3 is one of the vertexes of the triangle that has been acquired. The flag machine is moved from this vertex F3 to a vertex F4 and is set at the vertex F4. Then, the flag machine is moved to a vertex F5 and set at the vertex F5. In the illustrated example, the total of the area D1 of the previously acquired triangle and the area D2 enclosed by the sides 58 to 60 between the vertexes F3 to F5 is the total of the areas acquired by the team having the aforementioned flag machine. The total area (D1+D2) is compared with that of the opponent team to decide victory or defeat. In the case where the total of the three sides of a triangle is compared with that of the opponent team, the comparison may be made for each triangular figure.

[0055] If the round of the game is repeatedly performed, there will occur cases where the acquired area of one team overlaps part of the acquired area of the other team. In such cases, the place where the flag machine of the opponent team was installed can be predicated by utilizing the aforementioned interference. As illustrated in FIG. 8, it is now assumed that the acquired area of one team partially overlaps that of the other team. A triangle 54 shown by broken line indicates the acquired area of the A-team, while a triangle 55-1 shown by a broken line indicates the acquired area of the B-team. The interference area between the triangle 54 and 55-1 is indicated by a shaded portion 56-1. The display of FIG. 8 is the screen of the referee machine R. In the screens of the parent machines M_a, M_b, only the acquired area of the self-team and the interference area are displayed. The display screen of the parent machine Ma in the A-team is shown in FIG. 9A, and the display screen of the parent machine M_bin the B-team is shown in FIG. 9B. Thus, an area acquired by the opponent team is not displayed. The display screen of the parent machine M_ain the A-team is shown in FIG. 9A, and the display screen of the parent machine M_bin the B-team is shown in FIG. 9B. Thus, an area acquired by the opponent team is not displayed.

[0056] In FIG. 9A, an intersection 59-1 ca be obtained, if two sides 57-1, 58-1, not contacting with the three sides of a triangle 54, among the four sides of an interference area 56-1, are extended. In FIG. 9B an intersection 62 can likewise be obtained, if two sides 60-1, 61, not contacting with the three sides of a triangle 55-1, among the four sides of the interference area 56-1, are extended. The intersection 59 or 62 is one of the three vertexes of the triangle acquired by the opponent team. Therefore, with this result of prediction, the following rule (for extinguishing an area acquired by the opponent team can be positively utilized. This is able to increase the excitement of the game.

[0057] In the case where a vertex of a triangle acquired by an opponent team (hereinafter referred to as an inclusion vertex) is included in the interior of a triangle acquired by a self-team, the triangle of the opponent team having the inclusion vertex is invalidated and extinguished. If X the middle triangle in a plurality of continuous triangles is extinguished, triangles separated from the map of the team will occur and the supply line will be disconnected. Therefore, unless the separated state is eliminated or the team quickly rushes into the camp of the opponent team, the team has no alternative option to win the game. In this rule, instead of extinguishing a triangle, the triangle may be added to an area acquired by a self-team.

[0058] FIG. 10 illustrates how the game is actually performed pursuant to the rules mentioned above. The situations of war in both teams are displayed on the screen of the referee machine R. In the figure, reference characters A1 to A7 denote spots at which the flag machine of the A-team was set, and reference characters B1 to B7 denote spots at which the flag machine of the B-team was set. Subscript numbers 1 to 7 indicate the order in which the flag machine is set. In this example, the flag machine in the A-team has been set at the seventh spot A7, and similarly, the flag machine in the B-team has been set at the seventh spot B7. The interference areas between both teams are represented by reference numerals 63 to 65, respectively.

[0059] The progress of the game is displayed on the screen of the parent machine M_aof the A-team, as shown in FIG. 11. The progress of the game is also displayed on the screen of the parent machine M_bof the B-team, as shown in FIG. 12. The operator of the parent machine M_ain the A-team or the operator of the parent machine M_bin the B-team decides whether the self-team overruns the flag-machine spots of the opponent team or rushes into the opponent position, while viewing the display screen mentioned above. Based on the decision, the operator of the parent machine will transmit a proper command to the players of the self-team. The operator of the parent machine M_ain the A-team, for example, can predict some (B3 to B6) of the flag-machine spots of the opponent team, as shown in FIG. 11. Furthermore, the operator of the parent machine M_acan decide that the self-team should overrun the flag-machine spot B3, because the flag-machine spot B3 is located between the current flag-machine spot A7 of the self-team and the opponent position. According to this decision, the operator of the parent machine M_ain the A-team can transmit a proper advancing direction and a proper distance to the players of the self-team and set the flag machine at a spot so that the flag-machine spot B3 is included.

[0060] On the other hand, the operator of the parent machine M_bin the B-team can predict some (A5 to A7) of the flag-machine spots of the opponent team, as shown in FIG. 12. However, the flag-machine spots A5 to A7 are located on the side opposite to the advancing direction of the players of the self-team. In this case, it can be decided that rushing into the opponent position is preferable to overrunning the flag-machine spots A5 to A7. According to this decision, the operator of the parent machine M_bin the B-team can transmit a proper advancing direction and a proper distance to the players of the self-team and set the flag machine at a spot within the opponent position (beyond the line L_a).

[0061] In the case where the action of the B-team is faster than that of the A-team, the A-team is defeated. In the case where the action of the B-team has not been completed within a predetermined time, and the attack of the spot B3 by the A-team has been completed, the areas acquired by both teams are compared. In this case, probably the B-team will be defeated, because the triangle of the B-team is divided into two because of the loss of the spot B3.

[0062] According to the aforementioned embodiment, as described above, a game requiring movement of the body can be performed by utilizing GPS satellites. That is, a player sets an arbitrary spot within an extensive game area in cooperation with the other players of the self-team to acquire an area. If the round of the game is repeated, the players will overrun the spot acquired by the opponent team or rush into the opponent position. Furthermore, the progress of the game is made in a virtual game area. This can interest people being accustomed to indoor games such as television games, particularly young people. And young people are urged to join the game. Thus, the game system of the present invention is capable of making a contribution to the relation with people and the growth and health promotion of the body.

[0063] FIG. 13 illustrates another game rule suitable for the aforementioned embodiment. In the figure, two kinds of skull marks are disposed within the game area 50. One skull mark A_dis set at an arbitrary position by the A-team, while another skull mark B_dis set at another position by the B-team. The skull mark of an opponent team is not displayed on the screen of the parent machine of a self-team. If the players of the A-team set the flag machine so that the skull mark B_dis included, the skull mark B_dis displayed on the screen of the parent machine of the A-team when the triangle is formed, and the triangle is invalidated. That is, if it is set at a spot important to defense a self-team, the skull mark can block the way of an opponent team. Note that if the number of skull marks is excessively increased, it will disturb the game. Therefore, it is desirable that the maximum number of skull marks be determined by mutual consent. It is also desirable that the maximum number be managed by the referee machine.

[0064] While the present invention has been described with reference to the preferred embodiment thereof, the invention is not to be limited to the details given herein, but may be modified within the scope of the invention hereinafter claimed.