Patent Publication Number: US-2022219092-A1

Title: Game processing program, game processing method, and game processing device

Description:
CROSS-REFERENCE TO RELATED APPLICATION 
     This application is a continuation of U.S. patent application Ser. No. 15/948,295, filed Apr. 9, 2018, which claims priority to Japanese Application No. 2017-095050, filed May 11, 2017. The disclosures of each of which are hereby incorporated by reference. 
    
    
     BACKGROUND 
     The present disclosure relates to a game processing program, a game processing method, and a game processing device that present a game in which operation performed on a moving object in a game field is controlled. 
     A known game simulates the experience of operating a virtual moving object. Japanese Laid-Open Patent Publication No. 2010-119788 discloses an example of a fishing game in which a player casts a lure at a fishing spot where fish are likely to be present. When a fish bites on the lure, the player performs a reel winding action to catch the fish. 
     However, in the fishing game disclosed in Japanese Laid-Open Patent Publication No. 2010-119788, the player catches a fish that is right in front of the player. However, the movement of the fish in the above game is monotonous, whereas the movement of a real fish is complicated. 
     SUMMARY 
     It is an object of the present disclosure to perform complicated control of a moving object. 
     To achieve the above object, in one aspect of the present disclosure, a non-transitory computer-readable medium that stores a program is provided. The program, when executed by a processor, causes the processor to determine a movement range of a moving object in a game field using movement range information indicating the movement range of the moving object in the game field and arrange a game medium operated by a player in the game field so that a relative position of the game medium with respect to the movement range satisfies a predetermined condition. 
     In another aspect, a method for presenting a game is provided. The method includes, by circuitry, determining a movement range of a moving object in a game field using movement range information indicating the movement range of the moving object in the game field. Further, the method includes, by the circuitry, arranging a game medium operated by a player in the game field so that a relative position of the game medium with respect to the movement range satisfies a predetermined condition. 
     In a further aspect, a game processing device including circuitry is provided. The circuitry is configured to determine a movement range of a moving object in a game field using movement range information indicating the movement range of the moving object in the game field. The circuitry is further configured to arrange a game medium operated by a player in the game field so that a relative position of the game medium with respect to the movement range satisfies a predetermined condition. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
       The features of the present disclosure that are believed to be novel are particularly described in the accompanying claims. The present disclosure, together with objects and advantages thereof, may be understood by reference to the following description of the presently preferred embodiments together with the accompanying drawings in which: 
         FIG. 1  is a schematic diagram illustrating a first embodiment of a system; 
         FIG. 2  is a conceptual diagram illustrating a virtual space of the first embodiment; 
         FIG. 3  is a flowchart illustrating a game progress process of the first embodiment; 
         FIG. 4  is a flowchart illustrating an environment setting process of the first embodiment; 
         FIG. 5  is a conceptual diagram illustrating avatars displayed in a game field of the first embodiment; 
         FIG. 6  is a flowchart illustrating a standby mode process of the first embodiment; 
         FIGS. 7A to 7D  are schematic diagrams each illustrating an image displayed on a display during execution of the standby mode of the first embodiment; 
         FIG. 8  is a flowchart illustrating a main process for a battle mode of the first embodiment; 
         FIG. 9  is a flowchart illustrating an interrupt process for the battle mode of the first embodiment; 
         FIGS. 10A to 10D  are schematic diagrams each illustrating an image displayed on the display during the execution of the battle mode of the first embodiment; 
         FIGS. 11A to 11C  are schematic diagrams each illustrating an image displayed on the display during the execution of the battle mode of the first embodiment; 
         FIG. 12  is a flowchart illustrating the procedures for a main process for a moving object setting of the first embodiment; 
         FIG. 13  is a flowchart illustrating the procedures for an interrupt process for the moving object setting of the first embodiment; 
         FIGS. 14A to 14C  are schematic diagrams each illustrating an image displayed on the display during the execution of the moving object setting of the first embodiment; 
         FIG. 15  is a flowchart illustrating a main process for a battle mode of a second embodiment; 
         FIG. 16  is a flowchart illustrating an interrupt process for the battle mode of the second embodiment; 
         FIG. 17  is a flowchart illustrating an interrupt process for a moving object setting of a third embodiment; 
         FIGS. 18A to 18D  are schematic diagrams each illustrating an image displayed on the display during the execution of the moving object setting of the third embodiment; and 
         FIG. 19  is a schematic diagram illustrating a modified example of a system. 
     
    
    
     DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS 
     First Embodiment 
     A first embodiment of a game processing program, a game processing method, and a game processing device will now be described. In the present embodiment, the game processing device executes the game processing program in a state in which each player wears a head-mounted display (HMD) on the head, thereby presenting the player with a game in which a controller is used for input operations. In the present embodiment, a case in which two players simultaneously play the game will be described. 
     [Overview of System] 
     The systems of an HMD  10 , controllers  20 , and a game processing device  30  will now be described with reference to  FIG. 1 . First, the HMD  10  that is connected to the game processing device  30  will be described. The HMD  10  includes an HMD controller  11 , a sensor  12 , and an input/output interface (I/F)  13 . The HMD controller  11  outputs various information to the game processing device  30  via the input/output I/F  13  and receives various information that is input from the game processing device  30 . The sensor  12  is a sensor that detects motion of the head of a player including the position and orientation of the head of the player. The sensor  12  includes, for example, at least one of a gyro sensor, an acceleration sensor, and a geomagnetic sensor. 
     Further, the HMD  10  includes a display  14  for displaying an image and a speaker  15  for outputting audio. For example, the display  14  displays an image for the left eye and an image for the right eye with a parallax. This allows the player to look at a three-dimensional image with depth perception. The HMD controller  11  displays, on the display  14 , an image corresponding to an image signal received from the game processing device  30  via the input/output I/F  13 . The speaker  15  is, for example, a headphone and outputs a sound effect, audio or the like that explains the progress of the game. The sensor  12  and the speaker  15  may be arranged separately from the HMD  10 . 
     Each controller  20  detects motion of the controller  20  including the position and orientation of the controller  20 . The controller  20  includes, for example, at least one of a gyro sensor, an acceleration sensor, and a geomagnetic sensor. Further, the controller  20  includes a determination button. The controller  20  outputs, to the game processing device  30 , various information including the detection result of the motion of the controller  20  and whether or not the determination button has been operated (for example, tapping operation). The controller  20  may be a controller including an operation portion other than the determination button or may be a controller that accepts an input operation performed on the touch panel display. 
     [Game Processing Device  30 ] 
     The game processing device  30  will now be described. The game processing device  30  includes a control unit  31 , a memory unit  32 , and an input/output unit  33 . The control unit  31  includes hardware elements such as a CPU, a RAM, and a ROM. Further, the control unit  31  includes an operation state determination unit  34 , a game management unit  35 , and a display control unit  36 . In the present embodiment, the control unit  31  functions as the operation state determination unit  34 , the game management unit  35 , and the display control unit  36  by causing the hardware elements to execute the game processing program. 
     The memory unit  32  stores game field information  37 , avatar information  38 , moving object information  39 , item information  40 , operation state information  41 , and an object catching history  42 . 
     The game field information  37  is data used to draw the background of a game field shared by two players. The game field information  37  includes information related to the initial position for an avatar arranged in the game field by each player as a game element, information related to the type of moving object arranged in the game field, and the like. 
     The avatar information  38  is data used to draw the avatars arranged in the game field and respectively associated with the players when the game is executed. 
     The moving object information  39  is information related to a moving object displayed in the game field. The moving object information  39  includes movement range information used to set a movement range of the moving object in the game field, an attribute of an moving object (for example, parameter of moving object related to difficulty level indicating catching difficulty), and the like. The catching of a moving object means the provision of the moving object to a player and is achieved by recording identification information of the player in association with identification information of the moving object. 
     The item information  40  is information related to an item used to catch a moving object by operating the controllers  20 . The item information  40  includes an attribute of the item (for example, parameter of item that contributes to catching of moving object). 
     The operation state information  41  is information indicating the operation state of each controller  20 . The operation state information  41  includes information indicating the movement state including an operation speed that includes at least one of the speed, acceleration, and angular velocity of the controller  20 , information indicating the tilted direction of the controller  20 , information indicating whether or not the determination button of the controller  20  is operated, and the like. In the present embodiment, information indicating the operation state of the controller  20  is recorded for each controller  20  operated by the corresponding player. 
     The object catching history  42  includes information indicating the type of moving object that has been successfully caught by operating the controller  20 . The object catching history  42  is managed as individual history data for each player. 
     An operation signal is input to the operation state determination unit  34  of the control unit  31  from the controller  20  operated by each player via the input/output unit  33 . Further, the operation state determination unit  34  uses the input operation signal to determine the operation state of the controller  20  and record the determined operation state in the memory unit  32 . 
     The game management unit  35  manages the progress made in the game by a player. More specifically, if the player first selects a game field, an avatar is arranged in the selected game field. Further, the game management unit  35  uses movement range information corresponding to the type of moving object included in the game field information  37  to determine the movement range of the moving object in the game field. In addition, the game management unit  35  performs a catch operation on the moving object moving in the movement range in the game field based on operation states of the controllers  20  determined by the operation state determination unit  34 . If the catch operation on the moving object succeeds, the game management unit  35  adds the type and the like of the caught moving object to the object catching history  42 . If the catch operation on the moving object fails, the game management unit  35  ends the game. Additionally, the game management unit  35  extracts, from an audio information memory (not shown), audio information such as a sound effect and an audio explaining the progress of the game and transmits audio information to the speaker  15  via the input/output unit  33 . 
     The display control unit  36  determines an eyesight range in a virtual space centered about an attention position of each player and extracts the game field information  37  corresponding to the eyesight range. The display control unit  36  transmits the extracted game field information to the HMD  10  as an image signal. Further, the display control unit  36  displays the background of the game field selected by the player, an image of a moving object moving in the selected game field, and the like. In addition, the display control unit  36  displays, to each player, an avatar corresponding to the player in the game field. 
     [Operation Control] 
     The determination function of an operation state of each controller  20  by the game processing device  30  will now be described with reference to  FIG. 2 . The operation state determination unit  34  determines the position and orientation of the head of a player  101  corresponding to a detection signal of the sensor  12  input from the HMD  10 . More specifically, the operation state determination unit  34  calculates the position and orientation of the head as positions in three axes, namely, X-axis in a horizontal direction, Y-axis in a vertical direction, and Z-axis in a depth-wise direction, and angles about the three axes. A rotation angle about the X-axis is represented by a pitch θ p, a rotation angle about the Y-axis is represented by a yaw θy, and a rotation angle about the Z-axis is represented by a roll θr. The operation state determination unit  34  determines the eyesight position of the player in a virtual space  100  based on the determined position and orientation of the head. The attention position in the virtual space may be determined by determining only the orientation of the head of the player. The “attention position” is a point of the coordinates or a region in the virtual space. Further, the method for determining the attention position is not limited to the method described herein. 
     Further, the operation state determination unit  34  determines the position and orientation of each controller  20  based on various information such as the input operation signal of the controller  20 . More specifically, the operation state determination unit  34  calculates the position and orientation of the controller  20  as the positions in the three axes and the angles about the three axes in the same manner as the head of each player  101 . The operation state determination unit  34  determines the operation state of the controller  20  as viewed from the viewpoint of the player  101  by comparing the determined position and orientation of the controller  20  with the position and orientation of the head of the player  101 . 
     The display control unit  36  displays, at a position in the virtual space  100  corresponding to the controller  20 , an image of an item  103  used to operate moving objects in a game field  102 . In the present embodiment, an image of fishing rod used to catch moving objects is displayed near the hand of the player  101 . 
     The virtual space is shared by two players  101 . Thus, if operation performed by one of the players  101  is included in the eyesight range of the other one of the players  101 , the display  14  of the latter player  101  displays the operation performed by the former player  101 . Further, if operation performed by one of the players  101  causes a change in a moving object moving in the game field, the change is reflected on the display of the other one of the players  101 . 
     [Game Process] 
     Each process for presenting a game to a player will now be described with reference to  FIGS. 3 to 14 . In the present embodiment, each process will be described as an example game for catching a moving object. 
     When the game starts, the control unit  31  of the game processing device  30  determines the position and orientation of the head corresponding to the detection signal input from the sensor  12  of the HMD  10 . The control unit  31  determines an attention position of a player based on the position and orientation of the head. The control unit  31  extracts, from the memory unit  32 , the game field information  37  of an eyesight range centered about the attention position. The control unit  31  also transmits, to the HMD controller  11 , an image signal of a game field and a moving object that are included in the extracted game field information  37 . The control unit  31  determines the position and orientation of the controller  20  corresponding to an operation signal input from the controller  20 . The control unit  31  reads the item information  40  from the memory unit  32  and transmits, to the HMD controller  11 , an image signal of an item included in the read item information  40 . The HMD controller  11  outputs an image corresponding to the received image signal to the display  14 . More specifically, the HMD controller  11  outputs, to the display  14 , an image that displays the game field and the moving object at their respective predetermined positions in the virtual space. The HMD controller  11  outputs, to the display  14 , an image in which an item is displayed at the position corresponding to the controller  20 . In this manner, the game processing device  30  progresses the game while displaying, on the display  14 , an image of the virtual space that corresponds to the position and orientation of the head of the player as well as the position and orientation of the controller  20 . 
     [Game Progress Process] 
     The game progress process will now be described with reference to  FIG. 3 . 
     First, the control unit  31  of the game processing device  30  executes an environment setting of the game (step S 10 ). When the game starts, the control unit  31  reads the game field information  37  from the memory unit  32 . The process will be described later in detail with reference to  FIG. 4 . 
     Next, if the environment setting of the game is completed, the control unit  31  proceeds to a standby mode (step S 20 ). If a predetermined starting event is detected in the standby mode, the control unit  31  proceeds to a battle mode (step S 30 ). The process will be described in detail later with reference to  FIGS. 8 and 9 . 
     Then, the control unit  31  determines whether or not the player has performed a game ending operation after the battle mode ends (step  40 ). 
     If the game ending operation has not been performed (“NO” in step S 40 ), the control unit  31  returns to step S 20 . If the game ending operation has been performed (“YES” in step S 40 ), the control unit  31  causes the game to be ended. 
     [Environment Setting of Game] 
     The environment setting of the game will now be described with reference to  FIG. 4 . First, based on an operation signal input from the controller  20 , the control unit  31  of the game processing device  30  selects a game field selected by a player from a plurality of game fields that are prepared in advance (step S 11 ). 
     Next, the control unit  31  sets a moving object for the selected game field (step S 12 ). More specifically, the game management unit  35  of the control unit  31  determines the type of moving object corresponding to the selected game field based on the game field information  37 . Further, the game management unit  35  extracts, from the moving object information  39 , movement range information used to set a movement range of the determined moving object. The control unit  31  determines the movement range of the moving object in the game field based on the extracted movement range information. 
     Subsequently, the control unit  31  receives player information (step S 13 ). More specifically, the control unit  31  determines the number of players and a player ID for each player based on an operation signal input from the corresponding controller  20 . 
     Then, the control unit  31  sets an avatar (step  14 ). More specifically, the game management unit  35  of the control unit  31  reads the avatar information  38  from the memory unit  32  and sets an avatar for each player. Further, the game management unit  35  extracts, from the game field information  37 , information related to an initial position for the avatar corresponding to the selected game field. In this case, a plurality of positions are set in advance as the initial position for the avatar in the game field, and each position is determined based on movement ranges of moving objects. More specifically, the relative position of the avatar and a moving object is determined so that the distance from the initial position for the avatar to the movement range of the moving object is smaller than a predetermined distance. Thus, the movement range of at least one of the moving objects moving in the game field  102  is located proximate to the initial position for every one of the avatars. The control unit  31  randomly selects the initial position for an avatar for each player from the initial positions for the avatar corresponding to the game field. Alternatively, the control unit  31  selects the position designated by a player from the initial positions for the avatar. 
     The virtual space that is set through the environment setting of the game will now be described with reference to  FIG. 5 . The virtual space in  FIG. 5  is schematically shown irrelevant to the eyesight range of a player. 
     As shown in  FIG. 5 , a movable range  105  of moving objects  104  are set in the game field  102  selected by two players. In the present embodiment, a fishing spot corresponds to the game field  102 , fish correspond to the moving objects  104 , and a pond corresponds to the movable range  105  of the moving objects  104 . Movement target positions  106  of the moving objects  104  are set for the movable range  105  of the moving objects  104  based on the moving object information  39 . The number, arrangement, and movement probability of the movement target positions  106  (i.e., probability of a moving object  104  moving to each movement target position  106 ) differ depending on the type of the moving object  104 . The range surrounded by the movement target positions  106  corresponds to a movement range  107  of each moving object  104 . When a fish, which is the moving object  104 , exists in a pond (or river, sea, and the like), which is the movable range  105 , the fish is displayed by a fish outline. 
     Further, the game field  102  displays avatars  108  that are respectively set for the players. The movement range  107  of at least one of the moving objects  104  moving in the game field  102  is arranged to be included in the vicinity of the initial position for each avatar  108 . In the present embodiment, two moving objects  104  wander in the game field  102 , and the movement range  107  of one of the two moving objects  104  is arranged in the proximity of each of the avatars  108  of two players. This allows the two players to immediately start catching operation of moving objects  104  and smoothly progress the game without changing the positions of their avatars  108  from when the game starts. 
     [Standby Mode] 
     The standby mode will now be described with reference to  FIG. 6 . 
     First, the control unit  31  of the game processing device  30  detects operation performed in a first direction (step S 21 ). More specifically, the operation state determination unit  34  of the control unit  31  detects a swing-down operation of the controller  20 , as the operation performed in the first direction, from an operation signal input from the controller  20 . 
     Next, the control unit  31  executes a first operation rendering based on the operation state of the operation of the controller  20  in the first direction (step S 22 ). More specifically, the display control unit  36  of the control unit  31  arranges, in the game field, an item related to a catch operation performed on a moving object as the first operation rendering. The operation state of the operation performed in the first direction includes the operation speed and orientation of the operation of the controller  20  in the first direction. If an item is arranged in the game field, the control unit  31  controls the catching operation of the moving object to be ready to start. 
     Then, the control unit  31  determines whether or not a preparation condition of the operation of the controller  20  in a second direction has been satisfied (step S 23 ). In the present embodiment, a swing-up operation of the controller  20  is used as the operation performed in the second direction. More specifically, if the relative positions of a moving object and an item in the game field become closer and less than or equal to a predetermined distance, the operation state determination unit  34  of the control unit  31  associates the moving object with the item and determines that the preparation condition of the operation performed in the second direction has been satisfied. 
     If the control unit  31  determines that the preparation condition of the operation performed in the second direction has been satisfied (“YES” in step S 23 ), the control unit  31  determines whether or not the controller  20  has been operated in the second direction within a reference time (step S 24 ). More specifically, the operation state determination unit  34  of the control unit  31  waits for the operation performed in the second direction while measuring the time from when the preparation condition of the operation performed in the second direction is satisfied. 
     If the control unit  31  determines that the controller  20  has been operated in the second direction within the reference time (“YES” in step S 24 ), the control unit  31  executes a second operation rendering (step S 25 ). More specifically, the display control unit  36  of the control unit  31  outputs, to the HMD  10 , an operation rendering that displays a message indicating shifting to the battle mode in the vicinity of a moving object. 
     If the control unit  31  determines that the preparation condition of the operation of the controller  20  performed in the second direction has not been satisfied (“NO” in step S 23 ), the control unit  31  determines whether or not a cancellation operation has been performed (step S 26 ). More specifically, the operation state determination unit  34  of the control unit  31  waits for, as the cancellation operation, the swing-up operation of the controller  20  based on an operation signal input from the controller  20  that is operation performed in a direction opposite to the first direction. 
     If the cancellation operation is detected (“YES” in step S 26 ), the control unit  31  cancels the first operation rendering (step S 27 ) and returns to step S 21 . 
     If the cancellation operation is not detected (“NO” in step S 26 ), the control unit  31  returns to step S 23  while continuing the first operation rendering. 
     Further, the control unit  31  determines that the controller  20  has not been operated in the second direction within the reference time (“NO” in step S 24 ), cancels the first operation rendering (step S 27 ) and returns to step S 21  in the same manner. 
     The image displayed on the display  14  of the HMD  10  during execution of the standby mode will now be described with reference to  FIGS. 7A to 7D . 
     As shown in  FIG. 7A , the control unit  31  of the game processing device  30  displays, on the display  14 , an image of the virtual space in which the attention position of the player is located at the center of the eyesight range. In this case, the display control unit  36  of the control unit  31  displays, as the image of the virtual space, the game field  102 , the moving object  104  (fish) moving in the game field  102 , and the item  103  (fishing rod) associated with operation of the controller  20 . 
     As shown in  FIG. 7B , if the operation of the controller  20  in the first direction is detected, the control unit  31  executes the first operation rendering in which the item  109  (lure or bait) is arranged in the movable range  105  of the moving object  104 , which is set in the game field  102  as a set region. In the present embodiment, as the first operation rendering, a video is output in which a lure is thrown into a water surface of the pond from the head of the fishing rod. 
     In this case, the control unit  31  determines the position of the item  109  in the game field  102  based on a movement state (operation speed, orientation) of the controller  20  in the operation performed in the first direction. More specifically, the game management unit  35  of the control unit  31  arranges the item  109  at a farther position as viewed from the viewpoint of the player for a higher speed or higher acceleration of the controller  20  in the operation performed in the first direction (swing-down operation). In this case, the item  109  is arranged at a point on an extension line lying in the operation direction (swing-down direction), which is the first direction as viewed from the viewpoint of the player. 
     Further, as shown in  FIG. 7C , if the relative positions of the moving object  104  and the item  109  (for example, lure) in the game field  102  are proximate, the control unit  31  determines whether or not the moving object  104  is associated with the item  109  based on the affinity of the moving object  104  and the item  109 . More specifically, the game management unit  35  of the control unit  31  determines battle start (association of moving object  104  with item  109 ) based on the affinity of a fish and a lure or the like. The affinity of the bait set to the lure with the type of fish affects whether or not “hooking” in which the fish bites the lure has succeeded. 
     Further, if the moving object  104  and the item  109  are associated with each other, the control unit  31  issues a notification to the player. In this case, one example of a notification is to vibrate the controller  20  with a vibration function incorporated in the controller  20 . However, the notification is not limited to the vibration. Instead, a message may be displayed in the vicinity of the moving object  104  in the image of the virtual space. 
     Further, as shown in  FIG. 7D , if the operation of the controller  20  in the second direction is detected, the control unit  31  displays a message  110  indicating shifting to the battle mode in the vicinity of the moving object  104 . 
     [Battle Mode] 
     The battle mode will now be described with reference to  FIGS. 8 and 9 . In the present embodiment, the battle mode is a catching operation performed on the moving object  104  using the item  103  (fishing rod) and corresponds to a game operation using the item  103 . 
     First, as shown in  FIG. 8 , in a main process for the battle mode, the control unit  31  of the game processing device  30  displays a battle circle (step S 31 ). More specifically, the game management unit  35  of the control unit  31  displays the battle circle (first region) within the movable range of the moving object, which is set in the game field. The battle circle (first region) is a range in which a tap operation (first operation) performed on the determination button of the controller  20  is valid. Further, the size of the battle circle serves as an index indicating the health of the moving object or the probability of encountering an opportunity to catch the moving object. 
     Next, the control unit  31  enlarges the battle circle as time elapses (step S 32 ). More specifically, the game management unit  35  of the control unit  31  enlarges the diameter from the center of the battle circle as time elapses. The battle circle does not have to be circular as long as it is enlarged including the previous battle circle. 
     Then, the control unit  31  determines whether or not the size of the battle circle is smaller than a first threshold value (step S 33 ). More specifically, as described below, if an interrupt process for the battle mode is executed during enlargement of the battle circle, the game management unit  35  of the control unit  31  contracts the battle circle. The game management unit  35  compares the diameter of the battle circle with the first threshold value (lower limit threshold value). 
     If the control unit  31  determines that the size of the battle circle is greater than or equal to the first threshold value (“NO” in step S 33 ), the control unit  31  determines whether or not the size of the battle circle is greater than or equal to a second threshold value (step S 34 ). More specifically, the game management unit  35  of the control unit  31  compares the diameter of the battle circle with the second threshold value (upper limit threshold value). The second threshold value is set as a value larger than the first threshold value. 
     If the control unit  31  determines that the size of the battle circle is smaller than the second threshold value (“NO” in step S 34 ), the control unit  31  returns to step S 31 . More specifically, if the size of the battle circle is between the first threshold value and the second threshold value, the game management unit  35  of the control unit  31  repeats the processes of step S 31  to step S 34 . 
     If the control unit  31  determines that the size of the battle circle is smaller than the first threshold value (“YES” in step S 33 ), the control unit  31  determines whether or not the second operation of the controller  20  has been performed within the reference time (step S 35 ). More specifically, the operation state determination unit  34  of the control unit  31  waits for detection of the operation that swings up the controller  20  to catch the moving object (second operation). 
     If the second operation has been detected within the reference time (“YES” in step S 35 ), the control unit  31  executes a catch success rendering of the moving object (step S 36 ). More specifically, the display control unit  36  of the control unit  31  outputs, to the HMD  10 , a rendering in which a fish is lifted out from the water surface as the catch success rendering. 
     If the control unit  31  determines that the size of the battle circle is greater than or equal to the second threshold value (“YES” in step S 34 ), the control unit  31  performs a catch failure rendering of the moving object (step S 37 ). More specifically, the display control unit  36  of the control unit  31  outputs, to the HMD  10 , a rendering in which a fish is separated from the fishing rod as the catch failure rendering. 
     In addition, if the second operation of the controller  20  has not been detected within the reference time (“NO” in step S 35 ), the control unit  31  performs the catch failure rendering of the moving object (step S 37 ). 
     Further, as shown in  FIG. 9 , if the first operation of the controller  20  is detected during the execution of the processes of step S 31  to step S 34  in the main process for the battle mode (step S 31 A), the control unit  31  executes the interrupt process for battle mode. 
     In the interrupt process for the battle mode, the control unit  31  changes the size of the battle circle based on the validity of the first operation of the controller  20 . 
     First, at the point in time when the first operation is detected, the control unit  31  determines whether or not the moving object is located inside the battle circle (step S 32 A). More specifically, the operation state determination unit  34  of the control unit  31  determines a current position of the moving object to compare the current position with the location of the battle circle. 
     If the moving object is located inside the battle circle (“YES” in step S 32 A), the control unit  31  determines that the first operation of the controller  20  is valid. 
     In this case, the control unit  31  determines the contraction amount of the battle circle (step S 33 A). More specifically, the game management unit  35  of the control unit  31  determines the contraction amount of the battle circle at a ratio that has been determined in advance for each area of the battle circle. 
     Then, the display control unit  36  of the control unit  31  contracts the battle circle on the display  14  in correspondence with the determined contraction amount (step S 34 A) and ends the interrupt process for the battle mode. 
     If the moving object is located outside the battle circle (“NO” in step S 32 A), the control unit  31  determines that the first operation is invalid. 
     In this case, the control unit  31  enlarges the battle circle in correspondence with the first operation (step S 35 A) and ends the interrupt process for the battle mode. 
     The image displayed on the display  14  of the HMD  10  during the execution of the battle mode will now be described with reference to  FIGS. 10A to 10D  and  FIGS. 11A and 11C . 
     As shown in  FIG. 10A , the control unit  31  of the game processing device  30  displays, on the display  14 , an image of the virtual space in which the attention position of the player is located at the center of the eyesight range in the same manner as during the execution of the standby mode. In this case, the control unit  31  displays, as the image of the virtual space, the battle circle  111  centered about the position of the moving object  104  (fish) in the game field  102 . Further, the control unit  31  displays, inside the battle circle  111 , a central circle  112  (second region) indicating the lower limit threshold value of the size of the battle circle  111 . In addition, the control unit  31  displays, outside the battle circle  111 , an outer circle  113  indicating the upper limit threshold value of the size of the battle circle  111 . The central circle  112  and the outer circle  113  are concentric with the battle circle  111 . 
     The control unit  31  enlarges the battle circle  111  as time elapses. In this case, the control unit  31  changes an enlargement amount of the battle circle  111  as time elapses based on the type of the moving object  104  and the type of the item  103  (fishing rod), which is associated with operation of the controller  20 . 
     For example, for a moving object  104  having a high degree of rarity, a larger amount is set to the enlargement amount of the battle circle  111  as time elapses. This can increase the difficulty for catching the moving object  104 . 
     In addition, as shown in  FIG. 10B , if the first operation (tap operation) of the controller  20  is detected in a state in which the moving object  104  is located inside the battle circle  111 , the control unit  31  contracts the battle circle  111 . In this case, based on the area in the battle circle  111  where the moving object  104  is located, the control unit  31  changes the contraction amount of the battle circle  111  corresponding to the validity of the first operation of the controller  20 . 
     More specifically, the control unit  31  divides the battle circle  111  into a plurality of concentric areas in the radial direction and sets a contraction amount of the battle circle  111  for each area. In this case, the control unit  31  sets a larger contraction amount of the battle circle  111  to the area as the area becomes closer to the center of the battle circle  111 . 
     Further, the control unit  31  changes the contraction amount of the battle circle in correspondence with the validity of the first operation of the controller  20  based on the type of the moving object  104  and the type of the item  103 . 
     For example, for a moving object  104  having a high degree of rarity, a smaller amount is set to the contraction amount of the battle circle  111  if the first operation of the controller  20  is valid. This can increase the difficulty for catching the moving object  104 . 
     In addition, as shown in  FIG. 10C , if the battle circle  111  is contracted to the central circle  112 , the control unit  31  issues a notification indicating that the second operation of the controller  20  is valid. For example, the control unit  31  displays a message  114  in the vicinity of the moving object  104 . The notification may also be, for example, a method using the vibration function incorporated in the controller  20 . 
     If the second operation of the controller  20  is detected, the control unit  31  determines the validity of the operation. In this case, the validity of the second operation of the controller  20  is affected by a parameter of the item  103  (fishing rod) related to the second operation of the controller  20  that contributes to the difficulty for catching the moving object. The ratio in which a valid determination of the second operation of the controller  20  is given increases in correspondence with the level of the parameter of the item  103 . This can lower the difficulty for catching the moving object  104  when, for example, an item  103  having a high degree of rarity is used. 
     As shown in  FIG. 10D , if the control unit  31  determines that the second operation of the controller  20  is valid, the control unit  31  performs the catch success rendering of the moving object  104 . More specifically, the display control unit  36  of the control unit  31  outputs the rendering in which a fish is lifted out from the water surface to the HMD  10  as the catch success rendering. 
     In addition, as shown in  FIGS. 11A and 11B , if the first operation (tap operation) of the controller  20  is detected in a state in which the moving object  104  is located outside the battle circle  111 , the control unit  31  enlarges the battle circle  111 . In this case, based on the type of the moving object  104 , the type of the item  103  (fishing rod), which is associated with the first operation of the controller  20 , and the like, the control unit  31  changes the enlargement amount of the battle circle  111  corresponding to the validity of the first operation of the controller  20 . 
     For example, for a moving object  104  having a high degree of rarity, a large enlargement amount is set for the battle circle  111  if the first operation of the controller  20  is invalid. This can increase the difficulty for catching the moving object  104 . 
     As shown in  FIG. 11C , if the battle circle  111  is enlarged to the outer circle  113 , the control unit  31  performs the catch failure rendering of the moving object  104 . More specifically, the display control unit  36  of the control unit  31  outputs the rendering in which a fish is separated from the fishing rod to the HMD  10  as the catch failure rendering. If the control unit  31  determines that the second operation of the controller  20  is invalid, the control unit  31  performs the catch failure rendering of the moving object  104  in the same manner. 
     [Moving Object Setting] 
     A moving object setting will now be described with reference to  FIGS. 12 and 13 . A main process for the moving object setting shown in  FIG. 12  is executed in both the standby mode and the battle mode. An interrupt process for the moving object setting shown in  FIG. 13  is executed only in the battle mode and accepted during the execution of step S 31  to step S 34  in the main process for the battle mode. That is, in the present embodiment, in a state in which the second operation of the controller  20  is accepted as an operation state of the moving object, the interrupt process for the moving object setting is not accepted. In this regard, the control unit  31  of the game processing device  30  determines whether or not the moving direction of the moving object can be changed based on the operation state of the moving object. 
     [Main Process for Moving Object Setting] 
     First, as shown in  FIG. 12 , in the main process for the moving object setting, the control unit  31  determines a movement change timing (step S 51 ). More specifically, the game management unit  35  of the control unit  31  sets the movement change timing at predetermined time intervals. The game management unit  35  waits for the movement change timing. 
     Next, the control unit  31  randomly selects a movement target position (step S 52 ). More specifically, the game management unit  35  of the control unit  31  uses the moving object information  39  to determine, in the game field, candidates of a plurality of movement target positions corresponding to the type of the moving object  104 . Further, the game management unit  35  uses the moving object information  39  to determine the movement probability of the moving object  104  for each candidate of the movement target position. The game management unit  35  randomly selects the movement target position, which is a movement destination of the moving object, based on the movement probability for each candidate of the movement target position. 
     The game management unit  35  starts moving the moving object  104  from the current position on a straight line connecting the current position to a newly determined movement target position. In this case, the display control unit  36  of the control unit  31  outputs a display to the HMD  10  that causes the moving object  104  to wander to the movement target position. Subsequently, the control unit  31  returns to step S 51  and waits for the next movement change timing. 
     [Interrupt Process for Movement Object Setting] 
     As shown in  FIG. 13 , if an intervention operation of the controller  20  is detected during the execution of the main process for the moving object setting (step S 51 A), the control unit  31  executes the interrupt process for the moving object setting. That is, the intervention operation is executed under the assumption that the moving object and the item have been associated (“hooking” has succeeded). Further, the intervention operation is executed when the player changes the position or orientation of the controller  20 . 
     In the interrupt process for the moving object setting, the control unit  31  changes the movement direction of the moving object based on the direction of the intervention operation of the controller  20 . 
     First, the control unit  31  determines an intervention condition (step S 52 A). More specifically, the game management unit  35  of the control unit  31  determines the intervention condition using the type of moving object of the moving object information  39 , the type of item of the item information  40 , and the like. 
     Next, the control unit  31  determines whether or not the intervention operation of the controller  20  has succeeded (step S 53 A). More specifically, as the difficulty for catching the moving object becomes higher, the game management unit  35  of the control unit  31  decreases the probability of the intervention operation of the controller  20  determined as being successful. Further, as the parameter of the item that contributes to catching of the moving object becomes higher, the game management unit  35  increases the probability of the intervention operation of the controller  20  determined as being successful. In addition, when the acceleration or speed of the controller is greater than or equal to a predetermined value, the game management unit  35  may determine that the intervention operation has succeeded. 
     If the control unit  31  determines that the intervention operation of the controller  20  has succeeded (“YES” in step S 53 A), the control unit  31  changes the movement direction of the moving object (step S 54 A). More specifically, the game management unit  35  of the control unit  31  causes the direction of the intervention operation of the controller  20  to match the changed movement direction of the moving object. 
     If the control unit  31  determines that the intervention operation of the controller  20  has not succeeded (“NO” in step S 53 A), the control unit  31  ends the interrupt process for the moving object setting without changing the moving direction of the moving object. 
     The image displayed on the display  14  of the HMD  10  during the execution of the moving object setting will now be described with reference to  FIGS. 14A to 14C . 
     As shown in  FIG. 14A , the control unit  31  of the game processing device  30  moves the moving object  104  toward a predetermined one of a plurality of movement target positions  106  corresponding to the type of the moving object  104  in the game field  102 . The control unit  31  randomly selects a subsequent movement target position at predetermined time intervals based on the movement probability of each movement target position  106 . That is, the control unit  31  regularly changes the movement direction of the moving object  104  within the movement range  107 , which is surrounded by the movement target positions  106 . 
     As shown in  FIG. 14B , if the intervention operation of the controller  20  is detected, the control unit  31  determines whether or not the intervention operation of the controller  20  has succeeded. More specifically, the game management unit  35  of the control unit  31  determines whether or not the intervention operation of the controller  20  has succeeded based on the type of moving object, the type of the item  103  (fishing rod) associated with the intervention operation of the controller  20 , and the like. 
     As shown in  FIG. 14C , if the control unit  31  determines that the intervention operation of the controller  20  has succeeded, the control unit  31  changes the movement direction of the moving object  104  based on the direction of the intervention operation of the controller  20 . In this case, the changed direction of the moving object  104  is affected by the type of the moving object  104 , the type of the item  103  (fishing rod) associated with the intervention operation of the controller  20 , and the like. 
     For example, for a moving object  104  having a high degree of rarity, the degree of matching is low for the direction of the intervention operation of the controller  20  and the changed movement direction of the moving object  104 . This can increase the difficulty for catching the moving object  104 . 
     The control unit  31  may perform the intervention operation of the controller  20  to move the moving object  104  to a position located outside the movement range  107  that is set based on the movement range information. 
     Further, the control unit  31  does not accept the intervention operation of the controller  20  immediately after the movement direction of the moving object  104  is changed by the intervention operation of the controller  20 . The control unit  31  resumes changing of the movement direction of the moving object  104  by the intervention operation of the controller  20  under the condition that a predetermined time has elapsed from when the movement direction of the moving object  104  was changed. 
     As described above, the first embodiment has the following advantages. 
     (1) In the first embodiment, the movement range information is used to determine the movement range  107  of the moving object  104  in the game field  102 . The avatar  108  is arranged in the game field so that the relative positions of the avatar and the determined movement range  107  satisfy a predetermined condition. As a result, the moving object  104  moves in a complicated manner. Thus, when, for example, the moving object  104  is a fish, the movement is further close to that of a real fish. Further, the avatar  108  in the game field  102  and the movement range of the moving object  104  are properly arranged in order for the game to smoothly progress. 
     (2) In the first embodiment, a subsequent movement target position  106  is randomly selected from a plurality of movement target positions  106  set to the memory unit  32  at the movement change timing. Thus, the moving object  104  in the game field  102  has a wide variety of movement patterns. 
     (3) In the first embodiment, the movement change timing is set at predetermined time intervals. This regularly changes the movement direction of the moving object  104  and requires operation corresponding to the movement direction. Thus, the difficulty for catching the moving object  104  can be adjusted. 
     (4) In the first embodiment, the movement probability for each movement target position  106  is set to the memory unit  32 , and a subsequent movement target position  106  is randomly selected based on the movement probability at the movement change timing. Thus, the moving object  104  in the game field  102  has a wider variety of movement patterns. 
     (5) In the first embodiment, if a cancellation operation of the controller  20  is detected during the execution of the standby mode before the preparation condition is satisfied for operating the controller  20  in the second direction, the first operation rendering based on the operation of the controller  20  in the first direction is cancelled. Thus, the operation of the controller  20  can start the battle mode (game) and cancel starting of the battle mode. 
     (6) In the first embodiment, the position of the item  109  in the game field  102  is determined based on the movement state (speed, acceleration, and orientation) of the controller  20  operated in the first direction. Thus, the operation of the controller  20  can determine the position of the item  109  in the game field  102 . 
     (7) In the first embodiment, the validity of the first operation of the controller  20  is determined based on the battle circle  111  and the position of the moving object  104 , and the second operation of the controller  20  is valid if the battle circle  111  reaches the central circle  112 . Thus, in the game in which operation is performed on the moving object  104 , operation variations are increased. Further, the battle circle  111  is a display indicating when the first operation and the second operation are performed while the size of the battle circle  111  also changes in correspondence with the situation of the game. Thus, the viewpoint does not necessarily have to be moved to a region other than the battle circle in order to understand the game situation. This provides a user interface that allows for easy recognition of the game situation. Further, the game can be developed in correspondence with the battle circle  111  and the position of the moving object  104 . 
     (8) In the first embodiment, the size of the battle circle  111  is changed based on the validity of the first operation of the controller  20 . Thus, the first operation of the controller  20  can be linked with the difficulty for catching the moving object  104  using the battle circle  111 . 
     (9) In the first embodiment, the change amount of the battle circle  111  corresponding to the validity of the first operation of the controller  20  is determined for each area of the battle circle  111 . Thus, the difficulty for catching the moving object  104  can be changed in correspondence with the operation position of the controller  20  in the battle circle  111 . 
     (10) In the first embodiment, the change amount of the battle circle  111  is determined based on the type of the moving object  104 , the type of the item  103  associated with the first operation of the controller  20 , and the like. Thus, the types of the moving object  104 , the item  103 , and the like can be used to adjust the change in the size of the battle circle  111  and control the difficulty for catching the moving object  104 . 
     (11) In the first embodiment, if the size of the battle circle  111  reaches the outer circle  113 , the acceptance of the first operation of the controller  20  ends. Thus, the progress state of the game until when the first operation of the controller  20  ends can be understood from the battle circle  111 . 
     (12) In the first embodiment, if the size of the battle circle  111  reaches the central circle  112 , the second operation of the controller  20  is valid. Thus, the progress state of the game until when the second operation of the controller  20  is valid can be understood from the battle circle  111 . 
     (13) In the first embodiment, the movement range  107  of the moving object  104  in the game field  102  is determined based on the type of the moving object  104 . Thus, the difficulty for catching the moving object  104  can be respectively changed for each type of moving object using the battle circle  111 . 
     (14) In the first embodiment, if the intervention operation of the controller  20  is detected, the movement direction of the moving object  104  is changed based on the direction of the intervention operation of the controller  20 . Thus, the operation of the controller  20  can adjust the position of the moving object  104 . 
     (15) In the first embodiment, it is determined whether or not the intervention operation of the controller  20  has succeeded based on the type of the moving object  104 , the type of the item  103  associated with the intervention operation of the controller  20 , and the like. This diversifies the intervention operation in correspondence with the types of the moving object  104 , the item  103 , and the like. 
     (16) In the first embodiment, the changed movement direction of the moving object  104  is determined based on the type of the moving object  104 , the type of the item  103  associated with the intervention operation of the controller  20 , and the like. This diversifies the intervention operation in correspondence with the types of the moving object  104 , the item  103 , and the like. 
     (17) In the first embodiment, the changing of the movement direction of the moving object  104  by the intervention operation of the controller  20  is resumed under the condition that the predetermined time has elapsed from when the movement direction of the moving object  104  was changed by the intervention operation of the controller  20 . This allows the moving object  104  to wander again after the intervention. 
     Second Embodiment 
     A second embodiment of a game processing program, a game processing method, and a game processing device will now be described. The second embodiment differs from the first embodiment in that the processes for the battle mode are partially changed from that of the first embodiment. Like or same reference numerals are given to those components that are the same as the corresponding components of the first embodiment. Such components will not be described in detail. 
     The game of the present embodiment is the same as the first embodiment in that it is determined in correspondence with the validity of the first operation of the controller  20  whether or not a catching operation performed on a moving subject succeeds during the execution of the battle mode. In the present embodiment, the size of the battle circle does not change in correspondence with the validity of the first operation of the controller  20 , and the battle circle contracts as time elapses. That is, the battle circle is not repeatedly enlarged and contracted in correspondence with the validity of the first operation and instead continues to contract as time elapses. In this regard, the size of the battle circle serves as an index that indicates the elapsed time of the game. In this case, if the first operation of the controller  20  is determined as being valid, a count value that is temporarily stored in a memory is incremented. At the point in time when the size of the battle circle is smaller than a threshold value, the count value is used to determine whether or not the moving object has been successfully caught. 
     First, as shown in  FIG. 15 , in a main process for the battle mode, the control unit  31  of the game processing device  30  displays the battle circle (step S 131 ). More specifically, the game management unit  35  of the control unit  31  displays the battle circle (first region) within the movable range of the moving object that is set to the game field. 
     Next, the control unit  31  contracts the battle circle as time elapses (step S 132 ). More specifically, the game management unit  35  of the control unit  31  contracts the radius from the center of the battle circle as time elapses. The battle circle does not have to be circular as long as it is contracted so as to be included in the previous battle circle. 
     Then, the control unit  31  determines whether or not the size of the battle circle is smaller than the threshold value (step S 133 ). More specifically, the game management unit  35  of the control unit  31  compares the radius of the battle circle with the threshold value (lower limit threshold value). 
     If the control unit  31  determines that the size of the battle circle is greater than or equal to the threshold value (“NO” in step S 133 ), the control unit  31  returns to step S 131 . More specifically, the control unit  31  repeats the processes of step S 131  to step S 133  until the size of the battle circle reaches the threshold value. 
     If it the control unit  31  determines that the size of the battle circle is smaller than the threshold value (“YES” in step S 133 ), the control unit  31  determines whether or not the second operation of the controller  20  has been performed within a reference time (step S 134 ). 
     Then, if the second operation has been detected within the reference time (“YES” in step S 134 ), the control unit  31  determines whether or not the count value of a valid first operation of the controller  20  is greater than or equal to the threshold value (step S 135 ). The count value incremented in an interrupt process for the battle mode, which will be described later. 
     If the control unit  31  determines that the count value of the first operation of the controller  20  as being valid is greater than or equal to the threshold value (“YES” in step S 135 ), the control unit  31  executes a catch success rendering of the moving object (step S 136 ). 
     If the control unit  31  determines that the count value of the first operation of the controller  20  as being valid is smaller than the threshold value (“NO” in step S 135 ), the control unit  31  executes a catch failure rendering of the moving object (step S 137 ). 
     Also, if the second operation of the controller  20  has not been detected within the reference time (“NO” in step S 134 ), the control unit  31  executes the catch failure rendering of the moving object (step S 137 ). 
     The interrupt process for the battle mode will now be described with reference to  FIG. 16 . This process is executed if the first operation of the controller  20  is detected during the execution of the processes of step S 131  to step S 134  in the main process for the battle mode (step S 131 A). 
     At the point in time when the first operation is detected, the control unit  31  determines whether or not the moving object is located inside the battle circle (step S 132 A). 
     If the control unit  31  determines that the moving object is located inside the battle circle (“YES” in step S 132 A), the control unit  31  determines that the first operation of the controller  20  is valid. 
     In this case, the control unit  31  counts the first operation of the controller  20  as being valid (step S 133 A). More specifically, the game management unit  35  of the control unit  31  increments the count value that is temporarily stored in the memory and ends the interrupt process for the battle mode. 
     If the control unit  31  determines that the moving object is located outside the battle circle (“NO” in step S 132 A), the control unit  31  ends the interrupt process for the battle mode without counting the first operation of the controller  20  as being valid. 
     As described above, the second embodiment has the following advantage in addition to the advantages described in the first embodiment. 
     (18) In the second embodiment, the size of the battle circle does not change in correspondence with the validity of the first operation of the controller  20 . Thus, the elapsed time can be visually understood from the size of the battle circle, and the moving object can be caught by using the battle circle  111 . 
     Third Embodiment 
     A third embodiment of a game processing program, a game processing method, and a game processing device will now be described. The third embodiment differs from the first embodiment in that the interrupt process for the moving object setting of the first embodiment is partially changed. Like or same reference numerals are given to those components that are the same as the corresponding components of the first embodiment. Such components will not be described in detail. 
     The present embodiment is the same as the first embodiment in that the movement direction of the moving object is changed if the intervention operation of the controller  20  is performed. In the present embodiment, the method for changing the movement direction of the moving object is switched based on the relative positional relationship of the direction of the intervention operation of the controller  20  and the movement range of the moving object. 
     More specifically, as shown in  FIG. 17 , if the intervention operation of the controller  20  is detected during the execution of the main process for the moving object setting (step S 151 A), the control unit  31  of the game processing device  30  executes an interrupt process for the moving object setting. 
     In the interrupt process for the moving object setting, the control unit  31  changes the movement direction of the moving object based on the direction of the intervention operation of the controller  20 . 
     First, the control unit  31  determines an intervention condition (step S 152 A). 
     Next, the control unit  31  determines whether or not the intervention operation of the controller  20  has succeeded based on the determined intervention condition (step S 153 A). 
     If the control unit  31  determines that the intervention operation of the controller  20  has succeeded (“YES” in step S 153 A), the control unit  31  determines the relative positional relationship of the direction of the intervention operation of the controller  20  and the movement range of the moving object (step S 154 A). 
     If the control unit  31  determines that the direction of the intervention operation of the controller  20  is oriented toward the inside of the movement range of the moving object (“YES” in step S 154 A), the control unit  31  uses a first method to change the movement direction of the moving object (step S 155 A) and end the interrupt process for the moving object setting. The first method will be described later with reference to  FIGS. 18A and 18B . 
     If the control unit  31  determines that the direction of the intervention operation of the controller  20  is oriented toward the outer side of the movement range of the moving object (“NO” in step S 154 A), the control unit  31  uses a second method to change the movement direction of the moving object (step S 156 A) and end the interrupt process for the moving object setting. The second method will be described below with reference to  FIGS. 18C and 18D . 
     The image displayed on the display  14  of the HMD  10  during the execution of the moving object setting will now be described with reference to  FIGS. 18A to 18D . 
     It is assumed in  FIGS. 18A and 18B  that the control unit  31  of the game processing device  30  has detected the intervention operation of the controller  20  while the moving object  104  moves to the outer side of the movement range  107 . In this case, the control unit  31  uses the first method to change the movement direction of the moving object. In the first method, the control unit  31  randomly selects a subsequent movement target position  116  from a plurality of movement target positions  116  set for a central area  115  of the movement range  107  of the moving object  104 . 
     In this case, the control unit  31  changes the size of the central area  115  in which the movement target positions  116  are set based on the type of the moving object  104 , the type of the item  103  (fishing rod) associated with the intervention operation of the controller  20 , and the like. 
     For example, for a moving object  104  having a high degree of rarity, the central area  115  is large. This can increase the difficulty for catching the moving object  104 . 
     Further, it is assumed in  FIGS. 18C and 18D  that the control unit  31  has detected the intervention operation of the controller  20  while the moving object  104  moves to the inner side of the movement range  107 . In this case, the control unit  31  uses the second method to change the movement direction of the moving object. In the second method, the control unit  31  sets, as a subsequent movement target position  117 , a position where the direction of the intervention operation of the controller  20  intersects an outer edge of the movement range  107  of the moving object  104 . That is, the control unit  31  causes the direction of the intervention operation of the controller  20  to match the changed movement direction of the moving object. 
     As described above, the third embodiment has the following advantage in addition to the advantages described in the first embodiment. 
     (19) In the third embodiment, the changed movement direction of the moving object  104  is determined based on the relative positional relationship of the direction of the intervention operation of the controller  20  and the movement range  107  of the moving object  104 . Thus, the movement direction of the moving object  104  can be changed to various directions by the intervention operation of the controller  20 . 
     Each of the above embodiments may be modified as described below. 
     In each of the above embodiments, the initial position for the avatar  108  is set in advance at a plurality of positions in the game field  102 . The method for setting the initial position for the avatar  108  is not limited to the advanced setting. For example, if the game field  102  is selected by a player, the control unit  31  may determine the movement range  107  of the moving object  104  in the game field  102  and arrange the initial position for the avatar  108  at any proximate position. 
     In each of the above embodiments, the type of the moving object  104  is associated with the game field  102  in advance. The method for selecting the type of the moving object  104  is not limited to the advanced setting. For example, if the game field  102  is selected by a player, the control unit  31  may set the initial position for the avatar  108  in the game field  102  and select the type of the moving object  104  moving in the game field  102  based on the set position of the avatar  108 . 
     In each of the above embodiments, the movement change timing of the moving object  104  is set at predetermined time intervals. The method for determining the movement change timing is not limited to the predetermined time intervals. For example, the control unit  31  may set, as the movement change timing of the moving object  104 , a timing at which the moving object  104  reaches a predetermined movement target position  106 . 
     In each of the above embodiments, a movement probability is set for each of the movement target positions  106  of the moving object  104  in advance, and a subsequent movement target position  106  of the moving object  104  is randomly selected based on the movement probability. The method for randomly selecting the movement target position  106  is not limited to a method based on the movement probability. For example, the control unit  31  may randomly select a subsequent movement target position  106  from a plurality of movement target positions  106  corresponding to the moving object  104 . 
     In each of the above embodiments, the arrangement, number, and movement probability of the movement target positions  106  are set in advance in association with the game field  102  for each of the types of the moving object  104 . The method for setting the arrangement, number, and movement probability of the movement target positions  106  corresponding to the type of the moving object  104  is not limited to the advanced setting. For example, the control unit  31  may change the arrangement, number, and movement probability of the movement target positions  106  of the moving object  104  in correspondence with the progress of the game. 
     In each of the above embodiments, the position of the item  109  in the game field  102  is determined based on the speed or acceleration of the operation of the controller  20  in the first direction. Instead, the position of the item  109  in the game field  102  may be determined based on an operation time of the operation of the controller  20  in the first direction. For example, the control unit  31  detects the direction and acceleration of the swing-down operation of the controller  20  and calculates, as the operation time of the operation of the controller  20  in the first direction, a required time from when the operation starts to when the operation ends. The position of the item  109  in the game field  102  is determined based on the calculated operation time. In this case, as the operation time of the controller  20  in the first direction becomes longer, the control unit  31  determines the position of the item  109  at a farther position as viewed from the viewpoint of the player. 
     In each of the above embodiments, if the operation of the controller  20  in the first direction is detected, a position lying on the extension line of the controller  20  in the first direction as viewed from the viewpoint of the player is determined as the position of the item  109 . Instead, regardless of the operation direction of the controller  20 , a position lying on the extension line in the direction of the attention position of the player may be determined as the position of the item  109 . In this case, the control unit  31  determines an attention direction of the player in the HMD  10  and arranges the item  109  on the coordinates in the attention direction in the virtual space. Further, the position of the item  109  in the game field  102  may be determined by taking into account both the direction of the operation of the controller  20  and the direction of the attention position of the player. 
     In each of the above embodiments, the operation in the first direction (casting) is the swing-down operation of the controller  20 , and the operation in the second direction (cancelling) is the swing-up operation of the controller  20 . Instead, the operation performed in the first direction may be the operation that swings up and swings down the controller  20 , and the operation performed in the second direction may be the operation that swings up the controller  20 . Alternatively, the operation performed in the second direction may be operation that swings and/or turns the controller  20 . These operations can be changed in correspondence with the configuration of the controller  20 . For example, when the controller  20  includes a touch panel, the first operation may be a swipe operation or a flick operation performed on the touch panel, and the second operation may be the swing-up operation of the controller  20 . 
     In each of the above embodiments, the first operation is the tap operation performed on the determination button, and the second operation is the swing-up operation of the controller  20 . Instead, the first operation and the second operation may be the swing-up operation of the controller  20 , and the operation amount of the second operation may be larger than the operation amount of the first operation. Alternatively, the first operation and the second operation may be the swing-up operation of the controller  20 , and the lower limit value of the operation speed for performing the second operation may be larger than the lower limit value of the operation speed for performing the first operation. Further, the first operation and the second operation may be changed in correspondence with the configuration of the controller  20 . For example, when the controller  20  includes a touch panel, the first operation may be a swipe operation or a flick operation performed on the touch panel, and the second operation may be the swing-up operation of the controller  20 . 
     In each of the above embodiments, the battle circle  111  indicating the validity of the first operation of the controller  20  is displayed during the execution of the battle mode as an index of the progress state of the game until the second operation of the controller  20  is valid. In this case, the index of the progress state of the game until the second operation of the controller  20  is valid may be displayed separately from the display of the battle circle  111 . For example, the control unit  31  changes the initial value of a health gauge of the moving object  104  that is temporarily stored in the memory based on an operation state of the controller  20 . The health gauge of the moving object  104  is displayed in an upper area of the game field  102  in addition to the battle circle  111 . 
     In the second embodiment, the count value of the first operation of the controller  20  is calculated without taking into account the number of invalid first operations of the controller  20 . Instead, the count value of the first operation of the controller  20  may be calculated taking into account the number of invalid first operations of the controller  20 . For example, the control unit  31  calculates, as the count value of the first operation of the controller  20 , the value obtained by subtracting the number of invalid first operations of the controller  20  from the number of valid first operations of the controller  20 . 
     In the second embodiment, the number of valid first operations of the controller  20  is calculated as the count value of the first operation of the controller  20 . That is, the count value of the first operation of the controller  20  is calculated in the same manner for each area of the battle circle  111  if the first operation of the controller  20  is valid. Instead, the increment amount of the count value if the first operation of the controller  20  is valid may be separately set for each area of the battle circle  111 . 
     Further, if the first operation of the controller  20  is valid, the increment amount of the count value may be separately determined for each type of the moving object  104 , each type of the item  103  (fishing rod) associated with the first operation of the controller  20 , and the like. 
     For example, a small increment amount of the count value may be set for a moving object  104  having a high degree of rarity if the first operation of the controller  20  is valid. More specifically, the memory holds a table or a function to determine the increment amount of the count value (increment amount determination information) for each type of the moving object  104 . The increment amount corresponding to the difficulty for catching is set to the increment amount determination information. The control unit  31  determines the increment amount based on a moving object  104  that is subject to catching. Thus, the difficulty for catching the moving object  104  can be adjusted by, for example, setting a smaller increment amount as the degree of rarity becomes higher. 
     In the first and third embodiments, if the first operation of the controller  20  is valid, the contraction amount of the battle circle  111  is determined for each area of the battle circle  111 . The method for determining the contraction amount of the battle circle  111  is not limited to the method for determining the amount for each area. For example, the control unit  31  may set the same contraction amount of the battle circle  111  if the first operation of the controller  20  is valid without dividing the battle circle  111  into a plurality of areas. 
     In the first and third embodiments, the battle circle  111  is enlarged if the first operation of the controller  20  is invalid. The method for changing the battle circle  111  is not limited to the method for enlarging the battle circle  111  in correspondence with the validity of the first operation. For example, even if the first operation of the controller  20  is invalid, the control unit  31  may skip the process for enlarging the battle circle  111 . 
     In the first and third embodiments, the change amount of the battle circle  111  corresponding to the validity of the first operation of the controller  20  is determined based on the type of the moving object  104 , the type of the item  103  (fishing rod) associated with the first operation of the controller  20 , and the like. The method for determining the change amount of the battle circle  111  is not limited to the method based on the type of the moving object  104 , the type of the item  103 , and the like. For example, the control unit  31  may set the same change amount of the battle circle  111  corresponding to the validity of the first operation of the controller  20 . 
     In each of the above embodiments, the size of the battle circle  111  is changed as time elapses. The method for changing the battle circle  111  is not limited to the method based on the elapsed time. For example, regardless of the elapsed time, the control unit  31  may determine the size of the battle circle  111  based only on the validity of the first operation of the controller  20 . 
     In the first and third embodiments, the battle mode ends if the size of the battle circle  111  reaches the outer circle  113 . The condition for ending the battle mode is not limited to such a condition. For example, the control unit  31  may determine, as the ending condition, that the elapsed time of the battle mode has reached a predetermined time and that the number of invalid first operations of the controller  20  has reached a predetermined value. 
     In each of the above embodiments, it is determined whether or not the first operation of the controller  20  is started based on the affinity of the type of the moving object  104  and the type of the item  109  associated with the first operation of the controller  20 . The condition for determining whether or not the first operation of the controller  20  is started is not limited to such a condition. For example, the control unit  31  may use, as the determination condition, the affinity of the game field  102  and the type of the item  109  (lure) associated with the first operation of the controller  20 . In this case, for example, the type of the item  109  that can be used in the game field  102  is recorded in the item information  40 . 
     In each of the above embodiments, the second operation of the controller  20  is determined as being valid under the condition that the reference time has not elapsed from when the size of the battle circle  111  reached the central circle  112 . The condition for determining that the second operation of the controller  20  is valid is not limited to such a condition. For example, the control unit  31  may adopt a condition that the moving object  104  has not moved out of the battle circle  111 . In addition, if the size of the battle circle  111  reaches the central circle  112 , the control unit  31  may determine that the second operation of the controller  20  is valid until the second operation of the controller  20  is detected. 
     In each of the above embodiments, if the intervention operation of the controller  20  is detected, the movement direction of the moving object  104  can be changed to the outside of the movement range  107  of the moving object  104 , which is set based on the movement range information. Instead, the control unit  31  may limit the movement direction of the moving object  104  with the intervention operation of the controller  20  to the inside of the movement range  107 . 
     In each of the above embodiments, the changed movement direction of the moving object  104  is determined based on the direction of the intervention operation of the controller  20 . In addition to the direction of the intervention operation of the controller  20 , the movement direction of the moving object prior to changing may be further taken into account to determine the changed movement direction of the moving object  104 . For example, the control unit  31  generates vector components in the direction of the intervention operation of the controller  20  and vector components in the movement direction of the moving object  104  prior to changing to determine the direction of the combined vector as the changed movement direction of the moving object  104 . 
     In the third embodiment, a subsequent movement target position  116  of the moving object  104  is randomly selected from a plurality of movement target positions  116  set for the central area  115  if the direction of the intervention operation of the controller  20  is oriented toward the inside of the movement range  107  of the moving object  104 . The method for determining the movement target position  116  is not limited to such a method. For example, the movement probability of the moving object  104  is set in advance for each movement target position  116 , which is set in the central area  115 . The control unit  31  randomly selects a subsequent movement target position  116  of the moving object  104  based on the movement probability. 
     Further, the control unit  31  may randomly select a subsequent movement target position  116  of the moving object  104  based on the relative positional relationship of the direction of the intervention operation of the controller  20  and the movement target positions  116  set for the central area  115 . For example, the control unit  31  sets an extension line in the direction of the intervention operation of the controller  20  as viewed from the position of the moving object  104 . The control unit  31  determines a movement target position  116  that is most proximate to the extension line as a subsequent movement target position  116  of the moving object  104 . 
     Additionally, the control unit  31  may determine a predetermined position in the central area  115 , such as the center point of the movement range  107  of the moving object  104 , as a subsequent movement target position of the moving object  104  when the intervention operation of the controller  20  is performed. 
     In each of the above embodiments, it is determined whether or not the intervention operation of the controller  20  has been successfully performed based on the type of the moving object  104 , the type of the item  103  (fishing rod) associated with the intervention operation of the controller  20 , and the like. The condition for determining whether or not the intervention operation of the controller  20  has been successfully performed is not limited to such a condition. For example, the control unit  31  may use, as a condition, the affinity of the game field  102  and the item  103  (fishing rod) associated with the intervention operation of the controller  20 , the affinity of the moving object  104  and the item  103  (fishing rod) associated with the intervention operation of the controller  20 , and the like. Further, if the intervention operation of the controller  20  is detected, the control unit  31  may cause the intervention operation of the controller  20  to succeed without setting a precondition and randomly determine whether or not the intervention operation of the controller  20  has been successfully performed. 
     In each of the above embodiments, the changed movement direction of the moving object  104  is determined based on the type of the moving object  104 , the type of the item  103  associated with the intervention operation of the controller  20 , and the like. The condition for determining the changed movement direction of the moving object  104  is not limited to such a condition. For example, the control unit  31  may use, as a condition, the affinity of the game field  102  and the item  103  (fishing rod) associated with the intervention operation of the controller  20 , the affinity of the moving object  104  and the item  103  (fishing rod) associated with the intervention operation of the controller  20 , and the like. Further, if the intervention operation of the controller  20  is detected, the control unit  31  may determine the same changed movement direction for the moving object  104  based on the direction of the intervention operation of the controller  20 . 
     In each of the above embodiments, when the movement direction of the moving object  104  is changed by the intervention operation of the controller  20 , intervals are set to the timing for changing the movement direction of the moving object  104 . Instead, the control unit  31  does not have to set intervals to the timing for changing the movement direction of the moving object  104  by the intervention operation of the controller  20 . In this case, even when changing the movement direction of the moving object  104  by the intervention operation of the controller  20 , the control unit  31  continues to accept the intervention operation of the controller  20 . 
     Further, the lengths of the intervals may be variable based on the type of the moving object  104 , the type of the item  103  (fishing rod) associated with the intervention operation of the controller  20 , and the like. In this case, the control unit  31  maintains information used to set intervals in correspondence with the type of the moving object  104 , the type of the item  103 , and the like. 
     For example, for a moving object  104  having a high degree of rarity, long intervals may be set. This can increase the difficulty for catching the moving object  104 . 
     In each of the above embodiments, the case in which a game played by two players is presented is described. Instead, a game played by three players or more may be presented. In this case, the HMDs  10  that are equal in number to the players are connected to the game processing device  30 . 
     In each of the above embodiments, the game processing device  30  determines the position and orientation of the head of a player. Instead, the HMD controller  11  may obtain the position and orientation of the head based on a detection signal of the sensor  12 . As another option, the HMD  10  may be a device such as a smartphone including a touch panel and a communication unit and may include the control unit  31 . In this case, the control unit  31  of the device such as a smartphone consecutively obtains information via a network from a server that records, for example, the game field information  37  to cause the game to be executed. When multiple persons play the game, the HMDs  10  may communicate with one another and communicate via the server. Thus, the HMD  10  can have at least part of the functions of the game processing device  30  described in each of the above embodiments. 
     In each of the above embodiments, the HMD  10  determines the position and orientation of the head of a player. Instead, the HMD  10  may determine the position and orientation of a section of the player other than the head, for example, the position of an iris. 
     In each of the above embodiments, the game presented to a player is applied to a virtual reality game that displays a three-dimensional image on the display  14 . Instead, the above game may be a game that displays a two-dimensional image on the display. In this case, the HMD  10  may be changed to an installation-type display. The player operates the controller  20  while checking a display on the display and performs operation such as casting. 
     In each of the above embodiments, a plurality of players view a moving object in the virtual space from the perspective of the avatar  108  corresponding to each player. Instead, each player may be able to switch the viewpoint. For example, each player may view a moving object in the virtual space from a bird&#39;s-eye view at the rear of the avatar as well as from the viewpoint of the avatar. More specifically, in the virtual space, the control unit  31  sets, for the avatar, a viewpoint at a far side of the game field and outputs an image from this viewpoint to the HMD  10 . In this case, for example, each player may select a viewpoint before the game starts or may be able to change a viewpoint while playing the game. 
     The game device  30  may execute game control using the position of the game device  30 . In this aspect, as shown in  FIG. 19 , the game device  30  includes an absolute position acquisition unit  43 . The absolute position acquisition unit  43  acquires position information transmitted from a satellite positioning system such as a global positioning system (GPS). The control unit  31  of the game device  30  determines an absolute position of the game processing device  30  based on the information acquired by the absolute position acquisition unit  43 . Further, the memory unit  32  of the game device  30  stores game map data. The map data stores a region or a point where the game is executable in association with the absolute position. The region or the point where the game is executable is, for example, a region or a point where a fishing game is executable. The region or the point where the fishing game is executable may be determined using, for example, an old map. Referring to the acquired absolute position and the map data, the control unit  31  determines whether or not the position of the game device  30  is the region or the point where the fishing game is executable. If the control unit  31  determines that the position of the game device  30  is not the region or the point where the fishing game is executable, the control unit  31  does not set the fishing game to an executable state. For example, the display  14  of the HMD  10  does not display the region or the point such as sea, pond, and river where the fishing game is executable. If the control unit  31  determines that the position of the game device  30  is the region or the point where the fishing game is executable, the control unit  31  sets the fishing game to an executable state. For example, the display  14  of the HMD  10  displays the region or the point such as sea, pond, and river where the fishing game is executable. 
     In each of the above embodiments, a fishing game is presented as an example of a game. Instead, the present disclosure may be applied to other games. That is, the present disclosure may be applied to any game in which a player performs operation on a moving object based on the relative position of the avatar and the moving object in a game field.