Patent Publication Number: US-11642591-B2

Title: Game processing system, method of processing game, and storage medium storing program for processing game

Description:
CROSS-REFERENCE TO RELATED APPLICATIONS 
     This application is a Continuation Application of U.S. Ser. No. 16/268,756 filed on Feb. 6, 2019, which claims the benefit of priority from Japanese Patent Application Serial No. 2018-019003 (filed on Feb. 6, 2018), Japanese Patent Application Serial No. 2018-218087 (filed on Nov. 21, 2018. The subject matter of each of the above applications is incorporated herein by reference in entirety. 
    
    
     TECHNICAL FIELD 
     The present disclosure relates to a game processing system for processing a game that provides interaction with a virtual character, a method of processing a game, and a storage medium storing a program for processing a game. More specifically, the present disclosure relates to a game processing system for processing a game, a method of processing a game, and a storage medium storing a program for processing a game, the game being capable of providing interaction with a virtual character in accordance with detection information obtained by a head mounted display. 
     BACKGROUND 
     Simulation games that provide interaction with a virtual character are known. An example of these simulation games is disclosed in Japanese Patent Application Publication No. 2012-055644 (“the &#39;644 Publication”). 
     Games providing such interaction with a virtual character may utilize a head mounted display (hereinafter may be referred to as “HMD”) in order to enhance player&#39;s sense of immersion in the games. For example, known is a VR game in which a virtual space is displayed on an HMD, and a player wearing the HMD can interact with a virtual character appearing in the virtual space. The game “SUMMER LESSON” from BANDAI NAMCO Entertainment Co., Ltd. is known as this type of VR game (see “Summer Lesson”, [online], retrieved on 12, Dec. 2017, Internet (URL: HYPERLINK “http://summer-lesson.bn-ent.net/” http://summer-lesson.bn-ent.net/)). 
     As disclosed in Japanese Patent Application Publication No. 2017-058969 (“the &#39;969 Publication”), an HMD includes a tracking sensor for sensing the position and orientation of a head of a player. In VR games using an HMD, a viewpoint in a virtual space is set in accordance with detection information obtained by the tracking sensor, and an image of the virtual space as viewed from the viewpoint thus set is displayed on the HMD. 
     In the game “SUMMER LESSON,” realized is a function of specifying an interaction with a virtual character depending on detection information obtained by a tracking sensor of the HMD and causing the player to experience the specified interaction. 
     For example, when the player wearing the HMD nods in response to a movement of an image of a virtual character displayed on the HMD, a motion of the player&#39;s head corresponding to the nodding is detected. Based on the detected motion of the head, an image of the virtual character that performs an action responding to the nodding of the player is displayed on the HMD. 
     In this way, a conventional VR game in which interaction with a virtual character is performed using the HMD, an image of a virtual space is displayed so as to follow a motion of a player&#39;s head, and the player experiences interaction with the virtual character in accordance with the motion of the head so that the player can obtain a strong sense of immersion. 
     To play a VR game, a player needs to wear an HMD on his/her head. The HMD worn by the user blocks the view of the player in the actual world, and therefore, the VR game can be played in limited places and times. 
     SUMMARY 
     It is an object of the present disclosure to provide a technical improvement which solves or alleviates at least part of the drawbacks of the prior art mentioned above. 
     A game processing system according to an aspect is a game processing system for processing a game having a first mode and a second mode, the system comprising: a storage storing a game parameter relating to the game; and one or more computer processors. The one or more computer processors execute computer-readable instructions to: provide, in the first mode, an interaction with a virtual character in accordance with first detection information obtained by an information processing device not mounted on a head of a player; provide, in the second mode, an interaction with the virtual character in accordance with second detection information obtained by a head mounted display mounted on the head of the player; and update the game parameter in accordance with progress of the game in the first mode and the second mode. 
     In the game processing system according to an aspect, an action of the virtual character in the second mode is determined in accordance with the game parameter. 
     In the game processing system according to an aspect, the storage stores scene data relating to each of a plurality of game scenes constituting a game scenario in the second mode, and the one or more computer processors select a scene to be executed in the second mode from the plurality of game scenes in accordance with the game parameter. 
     In the game processing system according to an aspect, the one or more computer processors update the game parameter when the second mode is terminated abnormally. 
     In the game processing system according to an aspect, the one or more computer processors performs a switch process to switch from the first mode to the second mode such that a value of the game parameter as of an end of the first mode is equal to a value of the game parameter as of a start of the second mode. 
     A method of processing a game according to an aspect is a method of processing a game having a first mode and a second mode with one or more computer processors executing computer-readable instructions, the method comprising: providing, in the first mode, an interaction with a virtual character in accordance with first detection information obtained by an information processing device not mounted on a head of a player; providing, in the second mode, an interaction with the virtual character in accordance with second detection information obtained by a head mounted display mounted on the head of the player; and updating a game parameter relating to the game in accordance with progress of the game in the first mode and the second mode. 
     A game processing program according to an aspect stored in a non-transitory computer-readable storage medium is executed by one or more computer processors for processing a game having a first mode and a second mode. The game processing program causes the one or more computer processors to: provide, in the first mode, an interaction with a virtual character in accordance with first detection information obtained by an information processing device not mounted on a head of a player; provide, in the second mode, an interaction with the virtual character in accordance with second detection information obtained by a head mounted display mounted on the head of the player; and update a game parameter relating to the game in accordance with progress of the game in the first mode and the second mode. 
     Advantages 
     According to one aspect of the present disclosure, a game can be played in a first mode when the HMD is not usable. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         FIG.  1    is a block diagram illustrating a game processing system according to an embodiment. 
         FIG.  2    is a schematic diagram showing a head mounted display usable in the game processing system of  FIG.  1   . 
         FIG.  3    is a diagram schematically showing the head mounted display worn by a player of the game. 
         FIG.  4    schematically illustrates scenario data. 
         FIG.  5    is a diagram illustrating a mode switch in the game processed by the game processing system according to an embodiment. 
         FIG.  6    is a flowchart of a process in a chat mode according to an embodiment. 
         FIG.  7   a    shows an example of a display image in the chat mode according to an embodiment. The screen of  FIG.  7   a    shows options of a message that the player is able to select. 
         FIG.  7   b    shows an example of a display image in the chat mode according to an embodiment. The screen of  FIG.  7   b    shows the message selected by the player. 
         FIG.  7   c    shows an example of a display image in the chat mode according to an embodiment. The screen of  FIG.  7   c    shows a message for prompting the player to switch to a VR mode, a message for selecting settings in the VR mode, and a message for selecting an item used in the VR mode. 
         FIG.  7   d    shows an example of a display image in the chat mode according to an embodiment. The screen of  FIG.  7   d    shows a switch start object. 
         FIG.  8    is a flowchart of a mode switch process according to an embodiment. 
         FIG.  9   a    shows an example of an image displayed in the mode switch process according to one embodiment. The screen of  FIG.  9   a    shows guidance for prompting the player to attach a display to an attachment. 
         FIG.  9   b    shows an example of an image displayed in the switch process according to an embodiment. The screen of  FIG.  9   b    shows a switch object. 
         FIG.  10    is a flowchart of a process in a VR mode according to an embodiment. 
         FIG.  11    shows an example of an image displayed in the VR mode according to an embodiment. 
         FIG.  12    schematically shows a flow of actions taken by a virtual character in a scene executed in the VR mode. 
         FIG.  13    is a block diagram illustrating a game processing system according to another embodiment. 
     
    
    
     DESCRIPTION OF THE EMBODIMENTS 
     Various embodiments of the disclosure will be described hereinafter with reference to the accompanying drawings. Throughout the drawings, the same or similar components are denoted by the same reference numerals. 
     With reference to  FIGS.  1  to  3   , a game processing system according to an embodiment of the disclosure will be described.  FIG.  1    is a block diagram of a game processing system  1  according to an embodiment,  FIG.  2    schematically illustrates a head mounted display  10  (hereinafter referred to as “HMD  10 ”) used in the game processing system  1 , and  FIG.  3    schematically illustrates the HMD  10  worn by a player  5 . 
     The game processing system  1  according to an embodiment realizes various games by executing game processing programs according to an embodiment. Using the game processing system  1 , the player is able to play various games. For example, the game processing system  1  can realize a game in which a virtual character and the player interact in a virtual space. The game realized by the game processing system  1  has a first mode and a second mode. The game realized by the game processing system  1  includes a switch process to switch to the second mode. The same game contents are used in the first mode and the second mode. Game contents are electronic data that are used in a game and can be acquired, owned, used, managed, exchanged, integrated, reinforced, sold, abandoned, or donated in the game by users. The game contents include any content such as a card, an item, a virtual currency, a ticket, a character, an avatar, level information, status information, parameter information (health, attack, and the like), and statistic information (skills, abilities, magic, jobs and the like). However, the way the game contents are used may not be limited to those described in this specification. An example of the first mode is a chat mode, and an example of the second mode is a VR mode. The first mode and the second mode will be described later. 
     The game processing system  1  includes the HMD  10  and a server  50 . The HMD  10  and the server  50  are communicably interconnected over a network  40 . 
     As shown in  FIG.  2   , the HMD  10  includes an attachment  11  that is to be fitted on a human head and an information processing device  20  attached to the attachment  11 . 
     The attachment  11  includes a goggle-like casing  11   a  having an opening  11   d  formed therein, a first belt  11   b  and a second belt  11   c  attached to the casing  11   a , and a cover  11   e . The cover  11   e  is attached to the casing  11   a  such that it is openable and closable. An opening  11   d  is formed in a front portion of the casing  11   a .  FIG.  2    shows the state where the cover  11   e  is open. When the HMD  10  is used, the cover  11   e  is closed so as to close the opening  11   d.    
     The information processing device  20  is detachably provided on an inner side of the cover  11   e  of the HMD  10 . The information processing device  20  includes a display  24 . The information processing device  20  is attached to the cover  11   e  such that the display  24  faces the inside of the casing  11   a  when the cover  11   e  is closed. The information processing device  20  is attached to the attachment  11  when the HMD  10  is used. When the HMD  10  is not used, the information processing device  20  is detached from the attachment  11 . 
     In the illustrated embodiment, the information processing device  20  is a smartphone. In addition to the smartphone, the information processing device  20  may be a mobile phone, a tablet, a personal computer, an electronic book reader, a wearable computer, a game console, or any other information processing devices. The information processing device  20  detached from the HMD  10  is operated by the player  5  in the first mode as described later. In addition to games, the information processing device  20  detached from the HMD  10  may be used for telephone calls and Internet accesses depending on its originally intended use. 
     The information processing device  20  includes the display  24  as described above. In the illustrated embodiment, when the information processing device  20  is mounted on the attachment  11 , the display  24  serves as an apparatus for displaying an image in the HMD  10 . Accordingly, when the HMD  10  is used to play a game, the display  24  displays a virtual space and a virtual character(s) of the game, and other images related to the game. 
     The shape of the attachment  11  is not limited to the illustrated goggle type. The attachment  11  may include a structure of any shape that moves following the movement of the head of the player who wears the HMD, and the structure can place the display  24  in front of the wearer&#39;s eye(s) while the HMD is worn. For example, the attachment  11  may have an eyeglasses-like shape, a hat-like shape, or a helmet-like shape. In order to enhance player&#39;s sense of immersion, the HMD  10  may be configured such that the display  24  covers both eyes of the player when the attachment  11  is attached to the head of the player. 
     When the HMD  10  is used, the HMD  10  is mounted on the head of the player  5  via the attachment  11 , as shown in  FIG.  3   . The information processing device  20  is mounted on the attachment  11  attached to the head of the player  5 . 
     The information processing device  20  will be further described referring again to  FIG.  1   . As illustrated, in one embodiment, the information processing device  20  includes a computer processor  21 , a memory unit  22 , a communication I/F  23 , a display  24 , a sensor unit  25 , a sound collector  26 , and a storage  27 . 
     The computer processor  21  is a computing device which loads various programs realizing an operating system and game logics from the storage  27  or other storage into the memory unit  22  and executes instructions included in the loaded programs. The computer processor  21  is, for example, a CPU, an MPU, a DSP, a GPU, any other computing device, or a combination thereof. The processor  21  may be realized by means of an integrated circuit such as ASIC, PLD, FPGA, MCU, or the like. Although the computer processor  21  is illustrated as a single component in  FIG.  1   , the computer processor  21  may be a collection of a plurality of physically separate computer processors. In this specification, a program or instructions included in the program that are described as being executed by the computer processor  21  may be executed by a single computer processor or executed by a plurality of computer processors distributively. Further, a program or instructions included in the program executed by the computer processor  21  may be executed by a plurality of virtual computer processors. 
     The memory unit  22  is used to store instructions that may be executed by the computer processor  21  and other various data. At least a part of the game processing program in the embodiment is loaded into the memory unit  22  at appropriate timings in accordance with the progress of the game. The memory unit  22  is, for example, a main storage device (main memory) that the computer processor  21  is able to access at high speed. The memory unit  22  may be, for example, a RAM such as a DRAM or an SRAM. 
     The communication I/F  23  may be implemented as hardware, firmware, or communication software such as a TCP/IP driver or a PPP driver, or a combination thereof. The information processing device  20  is able to transmit and receive data to and from other devices via the communication I/F  23 . 
     The display  24  includes a display panel  24   a  and a touch-screen panel  24   b . For example, the display panel  24   a  is laminated on an upper surface or lower surface thereof with the touch-screen panel  24   b . The display panel  24   a  is a liquid crystal panel, an organic EL panel, an inorganic EL panel, or any other display panel capable of displaying an image. The touch-screen panel  24   b  is configured to detect touch interactions (touch operations) performed by the player. The touch-screen panel  24   b  can detect various touch operations such as tapping, double tapping, and dragging performed by the player. The touch-screen panel  24   b  may include a capacitive proximity sensor and may be capable of detecting a non-contact operation performed by the player. 
     The sensor unit  25  includes one or more sensors. The sensor unit  25  includes, for example, at least one selected from the group consisting of a gyro sensor, an acceleration sensor, and a geomagnetic sensor. The sensor unit  25  may include an eye tracking sensor that directly detects player&#39;s eye movements. The eye tracking sensor is, for example, an eye-gaze tracking sensor that emits a near-infrared light beam into the iris and detects its reflected light. The position and the direction of the head of the player  5  wearing the HMD  10  are specified based on detection information obtained by the sensor unit  25  as described later. 
     The sound collector  26  is capable of collecting sound and voice. The sound collector  26  is, for example, a microphone. Sound and voice of the player  5  is detected based on audio information collected by the sound collector  26 . 
     The storage  27  is an external storage device accessed by the computer processor  21 . The storage  27  is, for example, a magnetic disk, an optical disk, a semiconductor memory, or various other storage device capable of storing data. Various programs such as a game processing program are stored in the storage  27 . The storage  27  may also store various data used in a game(s). At least some of the programs and various data that can be stored in the storage  27  may be stored in a storage that is physically separated from the information processing device  20 . 
     In the illustrated embodiment, the storage  27  stores image data  28   a , chat data  28   b , scenario data  28   c , parameter data  28   d , game progress data  28   e , and various other data necessary for progress of the game. 
     The image data  28   a  includes data for drawing a background in a virtual space where a game is executed, data for drawing a virtual character, and data for drawing an object other than the virtual character used in the game. The image data  28   a  may include information about the position of an object in the virtual space. 
     The chat data  28   b  includes data for drawing an icon of a virtual character, data for drawing an icon of the player  5 , data for specifying a plurality of messages from a virtual character, data representing options of a response message to the plurality of messages from the virtual character, and any other data used in the chat. The plurality of messages from the virtual character may be defined in a tree structure in which nodes corresponding to each message are interconnected by arcs. In the tree structure, for example, more than one arc extends from a start message which is the root node existing at the top, and each arc is connected to a node situated at a lower level. Arcs also extend from the lower nodes and are connected to nodes at a further lower level. The nodes at the lower levels each correspond to a possible message from a virtual character that may be displayed after the start message. The chat data  28   b  may include a mode switch condition that is a condition for starting a mode switch from the chat mode to the VR mode. The mode switch condition may include, for example, that the elapsed time since the game was started in the chat mode is equal to or longer than a predetermined length of time, that a chat has progressed to a terminal node of messages having the tree structure, and any other conditions. The chat data  28   b  may include data indicating a message that is to be displayed when the chat mode is resumed after selection of a switch object is not completed. 
     The scenario data  28   c  includes data defining a scenario experienced by the player  5  in the second mode (e.g., the VR mode) of the game. When there are two or more scenarios to be experienced by the player  5  in the game, the scenario data  28   c  may be defined for each of the scenarios. 
     With reference to  FIG.  4   , scenario data used in the game processing system according to an embodiment will be described.  FIG.  4    schematically shows the scenario data  28   c  used in the game processing system  1 . The scenario data  28   c  is a data set for defining a scenario to be executed in the VR mode. In the illustrated embodiment, the scenario data  28   c  includes first scenario data  28   c   1  to fifth scenario data  28   c   5  corresponding to a first scenario to a fifth scenario, respectively. There may be six or more scenarios or may be four or less scenarios in the VR mode. Data structure of the first scenario data  28   c   1  corresponding to the first scenario will be now described. The description on the first scenario data  28   c   1  below also applies to the second scenario data  28   c   2  to the fifth scenario data  28   c   5 . 
     In the illustrated embodiment, the first scenario data  28   c   1  includes opening scene data A 1 , basic scene data B 1  to B 3 , additional scene data C 1  to C 3 , and ending scene data D 1  to D 2 . In one embodiment, the opening scene data A 1 , the basic scene data B 1  to B 3 , the additional scene data C 1  to C 3 , and the ending scene data D 1  to D 2  may each include data concerning actions of a virtual character in a corresponding scene, data concerning moving images used in the scene, data concerning actions that the player can do responsive to the virtual character in the scene, and any other data necessary for executing the scene. 
     In the illustrated embodiment, the opening scene data A 1  includes data concerning an action of the virtual character in an opening scene executed after the first scenario has started, data concerning a moving image used in the opening scene, data concerning actions that the player can do responsive to the virtual character in the opening scene, and any other data necessary for executing the opening scene. 
     The basic scene data B 1  to B 3  include data relating to actions of the virtual character in basic scenes executed after the opening scene, data relating to a moving image used in the basic scene, data relating to actions that the player can make to the virtual character in the basic scene, and any other data necessary for executing the basic scene. The basic scene data B 1  to B 3  may each include information indicating conditions for switching to an additional scene to determine whether switching to the additional scene is possible or not. The condition for switching to the additional scene may be determined for each basic scene. The condition for switching to the addition scene is, for example, that the player gazes at a predetermined object for a predetermined period of time or longer, the player does not look fixedly at a predetermined direction, and the player does a prescribed action. Other than the above-mentioned ones, the conditions for switching to the addition scene can be appropriately determined depending on the story of a scenario, a type of an object appearing in the virtual space, and other factors. 
     The additional scene data C 1  to C 3  include data concerning actions of the virtual character in an additional scene, data concerning a moving image used in the additional scene, data concerning actions that the player can do responsive to the virtual character in the additional scene, and any other data necessary for executing the additional scene. It is determined whether the condition for switching to the additional scene is satisfied during or after the basic scene is executed, and then the additional scene is executed in accordance with the determination result. 
     The ending scene data D 1  to D 2  may include data necessary for executing an ending scene before the second mode is terminated. The ending scene data D 1  to D 2  include data concerning actions of the virtual character in the ending scene, data concerning a moving image used in the ending scene, data concerning actions that the player can do responsive to the virtual character in the ending scene, and any other data necessary for executing the ending scene. 
     The parameter data  28   d  includes a game parameter relating to a game realized in the game processing system  1 . The game parameter may be a player character parameter relating to a player character. The player character parameter may include a parameter representing a virtual character&#39;s favorability to a user character. Here, the virtual character is a non-player character. The game parameter may be updated as the game progresses. The parameter relating to the player character is not limited to the parameter representing the virtual character&#39;s favorability to the user character. The parameter relating to the player character is appropriately determined according to a type, the nature, the worldview of the game, or other elements. 
     The game progress data  28   e  includes data used for managing the progress of the game. The game progress data  28   e  may be updated as the game progresses. The game progress data  28   e  may include, for example, data related to points acquired by the player in the game, and any other various types of data that may vary depending on the progress of the game. 
     The components and functions of the information processing device  20  shown in  FIG.  1    are examples. The information processing device  20  applicable to the invention may include various components that are not shown. For example, the information processing device  20  may be provided with a speaker for outputting sound effect of the game and sound and voice of the virtual character. 
     Next, functions of the HMD  10  will be described. In the illustrated embodiment, various functions of the HMD  10  are realized by the computer processor  21  of the information processing device  20  executing computer readable instructions. The instructions executed by the computer processor  21  include instructions included in the game processing program according to an embodiment. 
     When the game processing program according to the embodiment is executed by the computer processor  21 , the game having the first mode and the second mode different from the first mode is realized in the game processing system  1 . The game realized in the game processing system  1  may further have a mode other than the first mode and the second mode. 
     In the first mode of the game realized in the game processing system  1 , processing relating to the game is performed based on first detection information detected by the information processing device  20  when the HMD  10  is not mounted on the player  5 , that is, when the information processing device  20  is detached from the attachment  11 . The first detection information may include information concerning a touch operation of the player  5  detected via the touch-screen panel  24   b  of the information processing device  20 , information concerning voice of the player detected by the sound collector  26 , and any other detection information that can be detected in the information processing device  20  when the HMD  10  is not attached to the player  5 . In the first mode, the player  5  is able to perform operations relating to the game using the information processing device  20  that is removed from the attachment  11 . Since the first mode is designed to play the game when the HMD  10  is not mounted on the player  5 , it is possible to display a non-stereoscopic image on the display  24 . 
     In the second mode of the game realized in the game processing system  1 , the game is played and progresses using second detection information detected by the HMD  10  attached to the head of the player  5 . The second detection information is, for example, detection information obtained by the sensor unit  25 . Based on the second detection information, head tracking information for determining the orientation of the head of the player  5  is calculated. The head tracking information may be information indicating the position of the head of the player  5  in addition to the orientation of the head of the player  5 . A process for progressing the game in the second mode may be performed based on, for example, the head tracking information calculated based on the second detection information. The process for progressing the game in the second mode may be performed using any other information in addition to the head tracking information. In preparation for playing the game in the second mode, the player  5  attaches the information processing device  20  to the attachment  11 , and places the attachment  11  with the information processing device  20  on his/her head. As described above, the second mode is designed such that the game is played while the HMD  10  is worn by the player  5 , so in one embodiment, a stereoscopic image that is stereoscopically viewed by the player  5  is displayed on the display  24  in the second mode. The stereoscopic image is displayed on the display  24  by, for example, a parallax barrier method. In the parallax barrier method, a left eye image and a right eye image are displayed on the display  24 . The stereoscopic image is a set of images including the left eye image and the right eye image configured to be stereoscopically viewed when displayed on the display utilizing the parallax of the left and right eyes. 
     The first mode is, for example, a chat mode. The chat mode is an example of the first mode. The chat mode provides a function that allows the player to chat with a virtual character via a text message. In the first mode, the player can experience interaction with a virtual character by chatting with the virtual character. Processes performed in the chat mode will be described later in detail. Here, the interaction means, in a broad sense, that the virtual character reacts to an action made by the player. The interaction with the virtual character includes an interaction performed as communication with the virtual character such as conversation with the virtual character. In this specification, an interaction performed as communication with a virtual character may also be referred to as a communicative interaction. In addition to the communicative interaction, the interaction with a virtual character may include a battle against the virtual character, a cooperative play to play the game in cooperation with the virtual character, and other interactions with a virtual character. In this specification, an interaction performed as a battle against a virtual character may be referred to as a battle interaction. In the specification, an interaction performed as a cooperative play with a virtual character may be referred to as a cooperative interaction. 
     The second mode is, for example, the VR mode. The VR mode provides a function that allows the player to perform various interactions with a virtual character, which is a non-player character appearing in the virtual space displayed on the display of the information processing  20 . Processes performed in the VR mode will be described later in detail. The VR mode is an example of the second mode, and the second mode may include any game mode in which a process for progressing the game is performed using the head tracking information. 
     In one embodiment, a game having the first mode and the second mode that is realized by the game processing system  1 , may be a game in which a player performs interactions with a virtual character other than the communicative interaction. In the game realized by the game processing system  1 , the communicative interaction may not be performed. The game according to one embodiment is played in a two-dimensional space in the first mode and played in a three-dimensional space in the second mode. The game according to one embodiment is played in a three-dimensional space in the first mode, whereas in the second mode, the game is played in a three-dimensional space displayed in a different manner than the three-dimensional space of the first mode (or in a three-dimensional space configured in a different manner than the three-dimensional space of the first mode). In one embodiment, the game realized by the game processing system  1  may use a game content(s) common to the first mode and the second mode. A content parameter associated with the game content may be carried over to/from the first mode from/to the second mode. For example, when a value of the content parameter of the specific game content is changed during playing the game in the first mode and thereafter the game switches to the second mode, the specific game content with the changed content parameter is used in the second mode. In one embodiment, a value of a content parameter of a specific game content may be changed when the game is switched from the first mode to the second mode and/or when the game is switched from the second mode to the first mode. The change of the content parameter of the game content may be either advantageous for the player  5  to progress the game or disadvantageous for the player  5 . In one embodiment, a game play result in the first mode may be reflected in the game played in the second mode, and a play result in the second mode may be reflected in the game played in the first mode. For example, experience points of the player  5  acquired in the first mode may be carried over to the second mode. 
     As described above, the first mode and the second mode of the game realized in the game processing system  1  are distinguished from each other. That is, the first mode is different from the second mode. In one embodiment, when the game implemented in the game processing system  1  is played in the first mode, the HMD  10  is not attached to the head of the player  5 , whereas when the game is played in the second mode, the HMD  10  is attached to the head of the player  5 . In the first mode, the game is processed based on the first detection information obtained by the information processing device  20  that is not attached to the head of the player  5 , whereas in the second mode, the game is processed based on the second detection information obtained by the HMD  10  that is attached to the head of the player  5 . 
     In one embodiment, a stereoscopic image is displayed on the display  24  in the second mode, whereas in the first mode, a non-stereoscopic image is displayed on the display  24  as described above. At least an image of a virtual character among the images used in the game is displayed as a stereoscopic image in the second mode, whereas in the first mode, the image of the virtual character is displayed as a non-stereoscopic image. 
     In one embodiment, a process of progressing the game in the first mode is performed without using the head tracking information calculated based on the second detection information, whereas in the second mode, a process of progressing the game is performed based on the head tracking information. 
     In one embodiment, the process of progressing the game in the first mode is performed in accordance with a touch operation detected via the touch-screen panel  24   b , whereas in the second mode, the process is not performed in accordance with the touch operation on the touch-screen panel  24   b.    
     In one embodiment, in the case where an interaction with a virtual character is provided in a game implemented in the game processing system  1 , the interaction with the virtual character is provided based on the first detection information obtained by the information processing device  20  that is not attached to the head of the player  5  in the first mode. In the second mode, the interaction with the virtual character is provided based on the second detection information obtained by the HMD  10  attached to the head of the player  5 . 
     After the game is started, it is possible to switch between the first mode and the second mode which are distinguished as described above. With reference to  FIG.  5   , the outline of the mode switch of the game processed by the game processing system  1  will be described. As shown, when the game is started in step S 1 , the chat mode, which is the first mode, is started in step S 2 . In this chat mode, upon start of a switching process for switching to the VR mode which is the second mode, the process shifts to step S 3  and the switching process to the second mode is carried out. When the switching process is completed, the VR mode, which is the second mode, is started in step S 4 . When the VR mode is terminated or interrupted, a return process to the chat mode is performed. 
     Functions realized by the computer processor  21  will be now described more specifically. The computer processor  21  functions as a chat mode execution unit  21   a , a switch processing unit  21   b , a VR mode execution unit  21   c , and a parameter management unit  21   d  by executing computer readable instructions included in the game processing program. At least some of the functions that can be realized by the computer processor  21  may be realized by a computer processor other than the computer processor  21  of the game system  1 . For example, at least some of the functions realized by the computer processor  21  may be realized by a computer processor mounted on the server  50 . 
     The chat mode execution unit  21   a  performs processing for providing the game in the chat mode as the first mode by executing a game processing program according to an embodiment. The chat mode executing unit  21   a  implements a function that allows the player  5  (or a character of the player  5 ) to chat with a virtual character that is the non-player character. After the player  5  logs in to the chat mode, the chat mode execution unit  21   a  displays a message from the virtual character and a message input or selected by the player  5  on the display  24 , and enables the player  5  to chat with the virtual character. Following the message from the virtual character, the chat mode execution unit  21   a  may display on the display  24  several response options for the player  5  to respond to the message. One alternative is selected from the response alternatives according to an operation of the player  5  and a message corresponding to the selected response is displayed on the display  24  as a message from the player  5 . The player  5  can select a desired one from the displayed response options by touching the touch-screen panel  24   b . The message from the virtual character and the response options for the player to respond to the message can be specified by referring to the chat data  28   b  in accordance with the game processing program. The message from the virtual character may be displayed together with an image of the virtual character, and the message from the player  5  may be displayed together with an image of the player  5 . The message from the virtual character may include a message for prompting the player to switch to the VR mode which is the second mode, a message for allowing the player  5  to select an option(s) for setting of the VR mode, and any other message associated with the VR mode. 
     In the chat mode, a switch start object for starting switching to the VR mode as the second mode is displayed in accordance with the progress of the chat. Display of the switch start object is performed in accordance with the game processing program when the mode switch condition is satisfied. The chat mode execution unit  21   a  is capable of detecting that the switch start object is selected based on a detection signal from the touch-screen panel  24   b  or any other user interface. When it is detected that the switch start object has been selected, the process for switching to the VR mode, which is the second mode, is started. 
     The switch processing unit  21   b  performs the process for switching from the first mode to the second mode. The switch process may include displaying a guidance on the display  24  to prompt a player to attach the information processing device  20  to the attachment  11 , and displaying the switch object on the display  24  such that it is selectable by the player&#39;s gazing. After displaying the switch object, the switch processing unit  21   b  receives a detection signal from the sensor unit  25  or another sensor and determines whether the switch object has been selected by gazing based on the detection signal. For the determination, the switch processing unit  21   b  calculates the position and orientation of the HMD  10  based on the detection signal from the sensor unit  25 , and specifies the position (point) at which the player  5  gazes based on the calculated position and orientation of the HMD  10 . The gazing point can be specified by various known methods. For example, the gazing point may be specified based on the detection signal of the eye tracking sensor. For example, the switch processing unit  21   b  measures the duration of time (gazing duration) during which the gazing point is on the switch start object, and when the gazing duration reaches a predetermined length, the switch processing unit  21   b  determines that the selection of the switch start object has been completed. After the switch processing unit  21   b  determines that the selection of the switch object has been completed, it starts the VR mode which is the second mode. 
     The VR mode execution unit  21   c  displays an image of the virtual character in the virtual space in accordance with the game processing program and realizes interactions between the virtual character and the player  5 . The VR mode execution unit  21   c  serves as a scene selection unit  21   c   1 , a detection unit  21   c   2 , an action determination unit  21   c   3 , and an image generation unit  21   c   4  when the game processing program according to one embodiment is executed by the processor  21 . 
     The scene selection unit  21   c   1  selects a game scene to be executed based on the scenario data  28   c  and other information as required. After logging in to the VR mode, the scene selection unit  21   c   1  selects the opening scene. After the opening scene is executed, the scene selection unit  21   c   1  selects a next scene to be executed based on the detection information provided by the HMD  10 , information stored in the storage  27  (for example, the parameter data  28   d ), and, any other information as necessary. 
     The detection unit  21   c   2  calculates the head tracking information for determining the orientation and/or the position of the HMD  10  based on the detection signal from the sensor unit  25  of the HMD  10 . The head tracking information is information indicating the orientation and/or the position of the HMD  10 . The head tracking information is determined based on the detection information from the sensor unit  25 . More specifically, the head tracking information is obtained such that the position and orientation of the HMD  10  mounted on the head are calculated as the position in the three-dimensional orthogonal coordinate system and the angle around each axis. The three-dimensional orthogonal coordinate system is, for example, an orthogonal coordinate system composed of a roll axis along the front-rear direction, a yaw axis along the vertical direction, and a pitch axis along the left-right direction. The detection unit  21   c   2  generates a virtual space depending on the determined position and/or orientation of the HMD  10  and outputs image information for depicting the virtual space to the display  24 . For example, the detection unit  21   c   2  can calculate the gazing direction or the gazing point based on the position and/or the orientation of the HMD  10 . 
     The action determination unit  21   c   3  determines an action of the player  5  using the HMD  10  based on the head tracking information. Moreover, the action determination unit  21   c   3  may specify an action (reaction) of the virtual character in the virtual space according to the determined action of the player  5 . The actions of the player  5  wearing the HMD  10  include nodding, shaking his/her head, any other actions accompanied by motions of the head, and eye movements. The action of the player  5  that causes the virtual character to make a reaction may include the player&#39;s eye movement. Such eye movement can be detected by the eye tracking sensor included in the sensor unit  25 . 
     The image generation unit  21   c   4  generates image information for a depicting area in the virtual space. The depicting area is determined by an angle of view or the like around the gazing point or gazing direction determined by the detection unit  21   c   2 . Based on the image information generated in this way, the image for the depicting area of the virtual space is displayed on the display  24 . For the generation of the image information, for example, the image data  28   a , the scenario data  28   c , the parameter data  28   d , the game progress data  28   e , and other data stored in the storage  27  may be used. When a virtual character appears in the depicting area, the image generation unit  21   c   4  generates image information of the virtual space including the virtual character performing the action specified by the action determination unit  21   c   3 , and the image generated in this manner is rendered on the display  24  as a stereoscopic image. In this way, an image of the virtual space including the image of the virtual character performing the action specified in response to the action of the player  5  is displayed on the display  24 . The image generation unit  21   c   4  may generate audio information corresponding to the action of the virtual character and the depicting area of the virtual space. The audio information is output to the speaker of the HMD  10 . 
     As described above, a motion image in which a virtual character moves in the virtual space is displayed on the display  24  by the VR mode execution unit  21   c , and voice and sound corresponding to the movement of the virtual character is output from the speaker. For example, when the virtual character speaks to the player  5 , a motion image in which the head and mouth of the virtual character move is displayed on the display  24 , and voice corresponding to words which the virtual character speaks is output from the speaker. In one embodiment, the player  5  interacts with the same virtual character in the VR mode and the chat mode. For example, a virtual character appearing in the VR mode has the same name as a virtual character appearing in the chat mode, and they have common appearance such that they can be recognized as the same character. It should be noted that the image of the virtual character is displayed as a stereoscopic image in the VR mode, whereas the image of the virtual character is displayed as a non-stereoscopic image in the chat mode, so that the images of the virtual character are different between the VR mode and the chat mode. However, such difference in representation format does not affect the identity of virtual characters. 
     The parameter management unit  21   d  updates the parameter data  28   d  as the game progresses. When the game is provided in the first mode, the parameter management unit  21   d  updates the parameter data  28   d  according to the progress of the game in the first mode, and when the game is provided in the second mode, the parameter management unit  21   d  updates the parameter data  28   d  according to the progress of the game in the second mode. 
     In a case where the parameter data  28   d  includes a parameter indicating the virtual character&#39;s favorability to the user character, the parameter management unit  21   d  may increase or decrease the value of the parameter depending on an action of the player  5  in the first mode and the second mode. When the first mode is the chat mode, the amount (for example, increase amount or decrease amount) or rate (increase rate or decrease rate) of change of favorability for each option of the message presented to the player  5  in the chat mode may be defined. In this case, the parameter management unit  21   d  specifies the change amount or change rate of the favorability depending on the message option selected by the player  5 , and updates the parameter data  28   d  based on the specified change amount or change rate of the favorability. In the VR mode, the change amount or the change rate of the favorability may be determined for each type of action that the player  5  makes. The parameter management unit  21   d  specifies the change amount or change rate of the favorability depending on the action of the player  5  and updates the parameter data  28   d  based on the specified change amount or change rate of the favorability. 
     When the second mode is the VR mode, an inappropriate action may be defined for the actions that the player  5  takes in the VR mode. The inappropriate actions may include player&#39;s moving his/her head with an acceleration equal to or greater than a predetermined value, glancing at the prohibited area in the virtual space, and repeating the same action for more than a predetermined number of times. In this specification, among actions that the player  5  does, actions other than the inappropriate actions may also be referred to as normal actions. When the inappropriate action is performed by the player  5 , the parameter managing unit  21   d  updates the parameter data  28   d  so as to decrease the favorability. Whereas when the normal action is made by the player  5 , the parameter management unit  21   d  updates the parameter data  28   d  so as to increases or decreases the favorability depending on the normal action. 
     When the game is being processed in the VR mode, the VR mode may incidentally end abnormally without going through the ending scene prepared in the VR mode. For example, when the power supply to the HMD  10  is lost or when a function of the system program force-quits the game processing program, the VR mode may be terminated abnormally. When the VR mode is abnormally terminated, the parameter management unit  21   d  updates the parameter data  28   d  so as to decrease the favorability. 
     A value of a game parameter included in the parameter data  28   d  may be changed when the game is switched from the first mode to the second mode and/or when the game is switched from the second mode to the first mode, and the parameter data  28   d  may be updated so as to reflect the change. The change of the game parameter during mode switch may be either advantageous for the player  5  to progress the game or disadvantageous for the player  5 . When the parameter data  28   d  include a plurality of game parameters, only a part of the plurality of game parameters may be changed when the game is switched from the first mode to the second mode and/or when the game is switched from the second mode to the first mode. When the parameter data  28   d  include a plurality of game parameters, a change amount or a change rate is set for each of the plurality of game parameters, and each of the game parameters may be changed based on the change amount or the change rate set therefor when the game is switched from the first mode to the second mode and/or when the game is switched from the second mode to the first mode. 
     The parameter data  28   d  may include a common parameter that can be used in both the first mode and the second mode. The player character parameter may be a common parameter. A value of a common parameter may be either changed or not changed when the game is switched from the first mode to the second mode and/or when the game is switched from the second mode to the first mode. When a value of a common parameter is changed, the parameter data  28   d  is updated so as to reflect the change. The change of the common parameter during mode switch may be either advantageous for the player  5  to progress the game or disadvantageous for the player  5 . 
     The parameter data  28   d  may include a first mode parameter that is used in the first mode but is not used in the second mode and a second mode parameter that is used in the second mode but is not used in the first mode. Both the first mode parameter and the second mode parameter are included in the game parameters. The first mode parameter and the second mode parameter may be associated with each other. For example, when the first mode parameter is changed in the first mode, the second mode parameter associated with the first mode parameter may be changed in accordance with the change of the first mode parameter. Conversely, when the second mode parameter is changed in the second mode, the first mode parameter associated with the second mode parameter may be changed in accordance with the change of the second mode parameter. When the first mode parameter and the second mode parameter are changed, the parameter data  28   d  may be updated so as to reflect the change. In one embodiment, one example of the first mode parameter is the virtual character&#39;s favorability to the user character used in the first mode (a first mode favorability), and one example of the second mode parameter is the virtual character&#39;s favorability to the user character used in the second mode (a second mode favorability). For example, when the first mode favorability rises in the first mode, the second mode favorability rises accordingly. In another embodiment, one example of the first mode parameter is the virtual character&#39;s favorability to the user character used in the first mode (a first mode favorability), and one example of the second mode parameter is a game parameter used in the second mode other than the favorability (for example, the attack power of the player character). In this way, the first mode parameter and the second mode parameter may be game parameters of the same type or game parameters of different types. 
     When a termination condition is satisfied, the VR mode execution unit  21   c  performs a termination process to terminate the VR mode. The termination condition may include, for example, that a predetermined duration of time (for example, one minute) has elapsed from the start of the VR mode, that an operation for termination has been detected, that the last event included in the scenario being executed in the VR mode has ended, and any other conditions. The termination process performed when the termination condition is satisfied may include, displaying, on the display  24 , a guidance for prompting the player to remove the information processing device  20  from the attachment  11 , and displaying a login screen to log in to the chat mode which is the first mode. 
     Next, with reference to  FIG.  6    and  FIGS.  7   a  to  7   d   , a chat process in the chat mode will be described.  FIG.  6    is a flowchart showing the flow of the process in the chat mode in one embodiment, and  FIGS.  7   a  to  7   d    show examples of a display image in the chat mode. It is assumed that the HMD  10  is not mounted on the head of the player  5  and the information processing device  20  is detached from the attachment  11  at the start of the chat mode. 
     As described above, in the game processing system  1 , the game is started in the chat mode. In step S 11 , a login screen for logging in to the chat mode is displayed on the display  24  of the information processing device  20 . When the login process is performed by the player  5 , the chat process proceeds to step S 12 . 
     In step S 12 , the player  5  and the virtual character exchange messages thereby to perform a chat therebetween. More specifically, after logging into the chat mode, a chat display image for displaying a chat performed between the player  5  and the virtual character is generated, and the chat display image is displayed on the display  24 .  FIG.  7   a    shows a chat display image  70  which is an example of the chat display image displayed on the display  24 . The chat display image  70  has a chat display area  71  including an icon  73  corresponding to the player  5 , an icon  74  corresponding to the virtual character, a message  75   a  from the player  5 , and messages  76   a  and  76   b  from the virtual character. In addition, the chat display image  70  has a menu area  72  arranged at the top of the chat display area  71 . The virtual character&#39;s messages  76   a  and  76   b  are specified based on the chat data  28   b  and other data stored in the storage  72  in accordance with the game processing program. For example, messages of the virtual character are displayed sequentially from the message in the root node with reference to the chat data  28   b  defined in the form of the tree structure. At the branch point of nodes, a node is selected depending on a branch condition and a message corresponding to the selected node is displayed. 
     In step S 12 , a parameter set for the player  5  may be increased or decreased depending the option selected by the player  5 . As described above, the increase/decrease amount or change rate of the parameter is determined based on the change amount (for example, increase amount or decrease amount) or the change rate (increase rate or decrease rate) of the parameter determined for each option of the message. When the change amount or the change rate of the parameter is specified, the parameter data  28   d  is updated based on the specified change amount or change rate of the favorability. 
     The chat display image  70  in  FIG.  7   a    includes a display showing options  77  of the message for the player  5  to select at the lower part of the chat display area  71 . The player  5  is able to select one from among the displayed options  77 . The selection is performed, for example, by touching an area where the option desired to be selected is displayed on the display  24  with a finger. Once the selection is made, a message  75   b  corresponding to the selected option is newly displayed in the chat display area  71  as a message from the player  5 , as shown in  FIG.  7     b.    
     In the course of the chat process, messages  76   c  and  76   d  for prompting the player to select settings in the second mode VR mode may be displayed as messages from the virtual character as shown in  FIG.  7   c   . The message  76   c  is a message for prompting selection of a scenario in the VR mode, and the message  76   d  is a message for prompting selection of an item used by the virtual character in the VR mode (for example, clothes worn by the virtual character in the virtual space in the VR mode). In other words, the settings in the second mode include the scenario in the VR mode and the item used by the virtual character in the VR mode. After the message  76   c  prompting the selection of the scenario is displayed, choices of the scenario are displayed on the display  24 . For example, first to fifth scenarios are displayed as the choices. The player  5  is able to select one scenario that he/she likes from among these choices. After the message  76   d  prompting the player  5  to select an item is displayed, choices of the item are displayed on the display  24 . The player  5  can select one item that he/she likes from among the choices. In the course of a chat, a message for prompting the player to switch to the second mode may be displayed as a message from the virtual character. 
     In step S 13 , it is determined whether the mode switch condition from the first mode to the second mode is satisfied or not. An example of the mode switch condition from the first mode to the second mode is that a predetermined duration of time (for example, one minute) has elapsed from the start of the chat mode. The elapsed time from the start of chat mode is measured using, for example, a system clock. The process returns to step S 12  and the chat is continued until it is determined that the mode switch condition is satisfied. When it is determined that the mode switch condition is satisfied, the chat process proceeds to step S 14 . 
     In step S 14 , the switch start object  78  is displayed on the display  24 , and the chat process proceeds to step S 15 . As shown in  FIG.  7   d   , the switch start object  78  is displayed as, for example, an object having a circular profile in the chat display area  71 . When it is confirmed that the switch start object  78  is selected in step S 15 , the chat process proceeds to step S 16 . Whereas when the selection of the switch start object  78  is not confirmed even after a predetermined duration of time (for example, 10 seconds) has elapsed since the switch start object  78  is displayed, it is determined that the switch start object has not been selected and the chat process is terminated. Alternatively, the process may return to step S 12  and a process for resuming the chat may be performed when it is determined that the switch start object has not been selected. Whether the switch start object  78  is selected or not may be determined based on an operation performed on the touch-screen panel  24   b . For example, when an operation (for example, a tap operation) to touch the touch-screen panel  24   b  at a position overlapping the display area of the switch start object  78  is detected via a detection signal of the touch-screen panel  24   b , it is determined that the switch start object  78  is selected. Alternatively, the selection of the switch start object  78  may be made by a non-contact operation. 
     In step S 16 , a switch process to switch to the VR mode, which is the second mode, is started. When the switch process is started, the chat process is terminated. 
     The above chat process is executed by, for example, the chat mode execution unit  21   a . The chat mode execution unit  21   a  is capable of executing the above-described chat process alone or in cooperation with other functions as appropriate. The chat process may be performed using, as required, data stored in a storage other than the storage  27 , detection information obtained by various sensors, and any other data, in addition to the data stored in the storage  27 . 
     The mode switch process from the chat mode as the first mode to the VR mode as the second mode will be now described with reference to  FIG.  8    and  FIGS.  9   a  and  9   b   .  FIG.  8    is a flowchart of the mode switch process according to an embodiment. 
     When the switch process is started, a guidance that prompts the player to wear the HMD  10  is displayed on the display  24  of the information processing device  20  in step S 31 . A guidance display image  80  which is an example of the guidance display image including the guidance is shown in  FIG.  9   a   . The guidance display image  80  may include a guidance prompting the player to attach the information processing device  20  to the attachment  11 , a guidance prompting the player to wear the HMD  10  on the head, and any other various guidances necessary for starting the VR mode. The guidance display image  80  shown in  FIG.  9   a    includes a guidance  81  prompting the player to attach the information processing device  20  to the attachment  11 . This guidance may include instructions for attaching the information processing device  20  to the attachment  11 . When a predetermined time has elapsed after displaying the guidance, the mode switch process proceeds to step S 32 . 
     In step S 32 , the switch object is displayed on the display  24 . An example of the switch process image including the switch object is shown in  FIG.  9   b   . In the switch process image  85  shown in  FIG.  9   b   , a switch object  86  is included. The switch process image  85  may be displayed as a stereoscopic image. In one embodiment, the images displayed on the display  24  are switched from non-stereoscopic images to stereoscopic images at the start of the mode switch process or at a predetermined timing after the start of the mode switch process. For example, the images displayed in the chat mode are non-stereoscopic, and the images displayed after the switch process has started are stereoscopic. 
     Next, in step S 33 , it is determined whether selection of the switch object  86  is completed. The switch object  86  is selected, for example, by the player  5  gazing at the switch object  86  for a predetermined duration of time. Therefore, in order to select the switch object  86  in this state, the player  5  is required to wear the HMD  10 . In one embodiment, whether the selection of the switch object  86  is completed is determined based on whether the gazing point calculated based on the detection signal from the HMD  10  is situated on the switch object  86  for a predetermined amount of time or more. The gazing point may be calculated based on information obtained by the sensor unit  25  provided in the HMD  10  as described above. The above determination can be made by measuring a gazing time for which the gazing point stays on the switch object  86  using the system clock and determining whether the measured gazing time has reached the predetermined amount of time. For example, when the gazing time reaches the predetermined amount of time, it is determined that selection of the switch object  86  is completed, and the mode switch process proceeds to step S 34 . When completion of the selection of the switch object  86  is not detected even after a predetermined amount of time has elapsed since the switch object  86  is displayed, it is determined that the selection of the switch object  86  has not been completed, and the mode switch process proceeds to step S 35 . 
     In step S 34 , the VR mode, which is the second mode, is initiated. Processes performed in the VR mode will be described later in detail. 
     When the switch to the VR mode has not been selected, a process for returning to the chat mode is started in step S 35 . When the returning process to the chat mode is completed, the chat mode is resumed. In the resumed chat mode, a message from the virtual character based on the fact that the switch to the VR mode was not performed may be displayed. 
     The mode switch process described above is executed, for example, by the switch processing unit  21   b . The switch processing unit  21   b  is capable of executing the mode switch process alone or in cooperation with other functions as needed. 
     Next, a VR process in the VR mode will be described with reference to  FIGS.  10  to  12   .  FIG.  10    is a flowchart showing the flow of the VR process in the VR mode in one embodiment,  FIG.  11    shows an example of a display image in the VR mode, and  FIG.  12    schematically illustrates the flow of actions of the virtual character in a scene being executed in the VR mode. As described above, in order to select the switch object  86  in the mode switch process, the player  5  wears the HMD  10 . It is assumed that the HMD  10  is mounted on the head of the player  5  at the start of the VR mode. In the following, the VR process will be described on the premise that the first scenario is selected. In the VR process, the parameter data  28   d  is referred to when necessary. In one embodiment, the value of each game parameter included in the parameter data  28   d  as of the start of the VR process is equal to the value of the corresponding game parameter included in the parameter data  28   d  as of the end of the chat process. That is, in one embodiment, the parameter data  28   d  updated in the chat process is used without modification in the VR process. 
     When the VR mode is started, the opening scene is executed in step S 41 . More specifically, image information of the virtual space corresponding to the opening scene is generated, and an image according to the image information is output to the display  24 . In the opening scene, a predetermined action of the virtual character may be performed in the virtual space. 
       FIG.  11    shows an example of a VR image of the opening scene displayed on the display  24 . The VR image  90  shown in  FIG.  11    includes a virtual character image  91  representing the virtual character, images  92   a  to  92   c  representing objects constituting the background, and other images of various objects. The VR image  90  is an image corresponding to a predetermined range of the virtual space for the first scenario. The range of the virtual space corresponding to the VR image  90  may be specified as a range determined by an angle of view around the gazing point in the virtual space calculated based on the orientation of the HMD  10 . The image data  28   a  is used to generate the image information. The VR image  90  and other images displayed in the VR mode are displayed as stereoscopic images. 
     For example, the virtual character image  91  is able to take an action specified by opening scene data A 1  in the virtual space. For example, the action that the virtual character image  91  performs may include talking to the player  5  (toward the position of the player  5  in the virtual space), traveling in the virtual space, picking up an object placed in the virtual space, and any other various actions in the virtual space. 
     A series of actions performed by the virtual character in the opening scene will be described with reference to  FIG.  12   .  FIG.  12    schematically illustrates a flow of the actions taken by the virtual character in a scene executed in the VR mode.  FIG.  12    illustrates the flow of actions in the opening scene. As shown in  FIG.  12   , the virtual character first performs an action corresponding to an action A 11  in the opening scene. The action A 11  corresponds to an action that the virtual character can perform in the opening scene. For example, the action A 11  is an action of the virtual character talking to a character in the virtual space. 
     The action A 11  is defined as an action that may branch. More specifically, the action A 11  branches to an action A 21 , an action A 22 , and an action A 23 . For example, in the action A 11 , a first switch condition for switching to the action A 21 , a second switch condition for switching to the action A 22 , and a third switch condition for switching to the action A 23  are set. When the first switch condition is satisfied, the action of the virtual character is switched to the action A 21 . When the second switch condition is satisfied, the action of the virtual character is switched to the action A 22 . When the third switch condition is satisfied, the action of the virtual character is switched to the action A 23 . At least one of the first, second, and third switch conditions may be that the virtual character&#39;s favorability to the user character is equal to or greater than a predetermined threshold value. 
     Various conditions may be set as the first switch condition, the second switch condition, and the third switch condition. For example, the first switch condition, the second switch condition, and the third switch condition may include that the action prescribed as action A 11  has ended, that the player  5  performs a predetermined action (for example, the player  5  gazes at a predetermined part of the virtual character) to the virtual character, and that the player  5  answers a question from the virtual character. The first switch condition, the second switch condition, and the third switch condition are different from each other. The player  5  can answer the question from the virtual character by nodding, shaking his/her head, or other head motions. More specifically, when a question is made by the virtual character and the player makes action by moving his/her head, the movement of the head is detected by the sensor unit  25  of the HMD  10  and the answer of the player  5  is identified based on the detected movement of the head. For example, when a nodding motion is detected, it may be determined that the player  5  has made a positive answer. Whereas when a motion of shaking his/her head is detected, it may be determined that the player  5  has made a negative answer. Further, when a motion of the head of the player  5  is not detected for a predetermined duration of time after the question is made by the virtual character, it may be determined that the player  5  does not answer the question from the virtual character. The action of the player  5  may be determined by a function of the action determination unit  21   c   3 . 
     The action A 21  further branches to an action A 31  and an action A 32 . When a predetermined switch condition is satisfied in the action A 21 , switching from the action A 21  to the action A 31  or the action A 32  is performed depending on the established switch condition. Only the action A 33  is associated with the action A 22  in the lower layer. That is, the action A 22  is not branched. In this case, when the action A 22  ends, the action A 33  is started. No more action is defined below the action A 23 . The structure of the actions shown in  FIG.  12    is an example, and the types and the number of actions included in each scene and the structure of the actions may be set appropriately according to a story to be realized in the scene. 
     The switch from one action to another action may be performed seamlessly so that the player  5  does not perceive the action switch. 
     While the actions A 11 , A 21  to A 23 , and A 31  to A 33  are executed, the player  5  can take actions responsive to the virtual character by gazing at a predetermined part of the virtual character or any other method. In response to the action of the player  5  taken for the virtual character, the virtual character can take a reaction determined based on the start scene data A 1 . The virtual character may be controlled to make a reaction in accordance with the favorability. For example, for the same action of the player  5 , a friendly reaction may be made when the favorability is high, and an unfriendly reaction may be made when the favorability is low. 
     When the action A 31 , the action A 32 , the action A 33  in the terminal layer, or the action A 23  ends, the opening scene is ended and the VR process proceeds to step S 42 . 
     In step S 42 , the basic scene to be executed is selected from among a plurality of possible basic scenes. Selection of the basic scene to be executed is performed from among a plurality of possible basic scenes prepared for the first scenario, for example, according to the parameter data  28   d . In the first scenario, three basic scenes corresponding to the basic scene data B 1  to B 3  illustrated in  FIG.  4    are provided. In one embodiment, the basic scene to be executed is selected from among these three basic scenes based on the virtual character&#39;s favorability to the player  5 , the favorability is stored as the parameter data  28   d . For example, when the favorability is equal to or higher than a first threshold value, the basic scene corresponding to the basic scene data B 1  is selected. When the favorability is lower than a second threshold value, the basic scene corresponding to the basic scene data B 3  is selected. When the favorability is equal to or higher than the second threshold value and lower than the first threshold value, the basic scene corresponding to the basic scene data B 2  is selected. Selection of the basic scene may be performed by any other method other. For example, the basic scene may be randomly selected. The basic scene may be randomly selected after performing weighting of the possible basic scenes so that the probability that some basic scene(s) (for example, the first basic scene corresponding to the basic scene data B 1 ) are selected becomes higher as the favorability is higher. The method of selecting the basic scene is not limited to the method explicitly described in the specification. Once the basic scene is selected, the VR process proceeds to step S 43 . 
     In step S 43 , the basic scene selected in step S 42  is executed. More specifically, image information of the virtual space corresponding to the basic scene is generated, and an image corresponding to the image information is output to the display  24 . In the basic scene, the virtual character may take a prescribed action in the virtual space. As with the opening scene, the action which the virtual character takes in the basic scene may be defined as a series of branchable actions. A series of branchable actions in the basic scene may have a data structure similar to the data structure shown in  FIG.  12   . When the action situated in the bottom layer in the series of actions is completed, the basic scene ends and the VR process proceeds to step S 44 . 
     In step S 44 , it is determined whether the condition for switching to the additional scene set for the basic scene executed in step S 43  is satisfied. In the determination, the condition for switching to the additional scene included in the basic scene data (for example, the basic scene data B 1 ) corresponding to the basic scene executed in step S 43  is retrieved from the storage  27 , and it is determined whether the condition is satisfied in the basic scene executed in step S 43 . For example, when the switch condition is that the player gazes at an object representing a door in the virtual space for more than three seconds, counted is the duration of time in which the gazing point of the player  5  in the virtual space is located on the object representing the door, and it is determined that the switch condition is satisfied when the counted time is three seconds or longer. The gazing point of the player  5  in the virtual space is calculated on the basis of the orientation of the HMD  10  calculated based on the detection information from the sensor unit  25 . The condition for switching to the additional scene may or may not be explicitly presented to the player  5  at the time of execution of the basic scene. For example, in the basic scene, the virtual character may speak to the player  5  the line corresponding to the condition for switching to the additional scene. 
     When it is determined that the switch condition is not satisfied, the VR process proceeds to step S 45 , whereas when it is determined that the switch condition is satisfied, the VR process proceeds to step S 46 . 
     In step S 45 , a first ending scene is executed. More specifically, image information of the virtual space corresponding to the additional scene is generated, and an image corresponding to the image information is output to the display  24 . 
     In step S 46 , an additional scene is executed. More specifically, image information of the virtual space corresponding to the additional scene is generated, and an image corresponding to the image information is output to the display  24 . Similarly to the opening scene, the action that the virtual character takes in the additional scene may be defined as a series of branchable actions. A series of branchable actions in the additional scene may have a data structure similar to the data structure shown in  FIG.  12   . When the action situated in the bottom layer in the additional scene is completed, the additional scene ends and the VR process proceeds to step S 47 . 
     In step S 47 , a second ending scene is executed. More specifically, image information of the virtual space corresponding to the second ending scene is generated, and an image corresponding to the image information is output to the display  24 . The image displayed in the second ending scene may be the same as or different from the image displayed in the first ending scene. 
     When movement of the head of the player  5  is detected by the sensor unit  25  of the HMD  10  while the VR image  90  is displayed on the display  24 , an action of the player  5  is specified based on the detected movement of the head. Then, an action (reaction) of the virtual character responsive to the specified action of the player  5  is determined. Subsequently image information of the virtual character image  91  that performs the determined action is generated. The image information generated in this way is output to the display  24 . For example, when a nodding motion of the player  5  is detected, image information of the virtual character image  91  reacting to the nodding motion of the player  5  is generated, and the image information is displayed on the display  24 . In this manner, in the VR mode, interaction between the player  5  and the virtual character is realized using the stereoscopic image of the virtual character. 
     In the above-described steps S 41 , S 43 , S 45  to S 47 , the parameter(s) set for the player  5  may be increased or decreased according to the action(s) of the player  5 . As described above, the increase/decrease amount or change rate of the parameter may be determined based on the change amount (for example, increase amount or decrease amount) or the change rate (increase rate or decrease rate) of the parameter determined for each type of the action of the player  5 . When the change amount or the change rate of the parameter is specified, the parameter data  28   d  is updated based on the specified change amount or change rate of the favorability. 
     In step S 48 , the termination process of the VR mode is performed. The termination process may include displaying on the display  24  a guidance for prompting the player to remove the information processing device  20  from the attachment  11 , and displaying a login screen to log in to the chat mode which is the first mode. 
     The above VR process is executed by the VR mode execution unit  21   c . The VR mode execution unit  21   c  is capable of executing the VR process alone or in cooperation with other functions as needed. 
     The game processing system according to another embodiment will be described with reference to  FIG.  13   .  FIG.  13    is a block diagram illustrating a game processing system  101  according to another embodiment. The game processing system  101  includes the information processing device  20  and the HMD  110 . The game processing system  101  is different from the game processing system  1  in that the VR mode can be provided without attaching the information processing device  20  to the HMD  110 . Hereinafter, the game processing system  101  will be described focusing on the differences from the game processing system  1 . 
     The HMD  110 , the information processing device  20 , and the server  50  are communicably interconnected over the network  40 . The HMD  110  and the information processing device  20  may be connected so as to communicate with each other according to a short-range wireless system such as Bluetooth (registered trademark) without using the network  40 . The HMD  110  is different from the HMD  10  of the game processing system  1  in that the VR mode can be provided even if the information processing device  20  is not mounted. 
     The HMD  110  includes a computer processor  121 , a memory unit  122 , a communication I/F  123 , a display  124 , a sensor unit  125 , a sound collector  126 , and a storage  127 . The computer processor  121 , the memory unit  122 , the communication I/F  123 , the display  124 , the sensor unit  125 , the sound collector  126 , and the storage  127  are configured similarly to the computer processor  21 , the memory  22 , the communication I/F  23 , the display  24 , the sensor unit  25 , the sound collector  26 , and the storage  27  of the information processing device  20 , respectively. However, the display  124  may not have a touch-screen panel. 
     The functions of the chat mode execution unit  21   a , the switch processing unit  21   b , the VR mode execution unit  21   c , and the parameter management unit  21   d  are distributed between the information processing device  20  and the HMD  110 . Specifically, the function of the chat mode execution unit  21   a  is realized in the information processing device  20 , and the function of the VR mode execution unit  21   c  is realized in the HMD  110 . A part of the function of the switch processing unit  21   b  is realized by the information processing device  20 , and the rest is realized in the HMD  110 . The function of the parameter management unit  21   d  is realized by both the information processing device  20  and the HMD  110 . 
     The image data  28   a , the chat data  28   b , the scenario data  28   c , the parameter data  28   d , and the game progress data  28   e  are stored in one or both of the storage  27  and the storage  127 . Alternatively these data may be stored in a storage other than the storage  27  and the storage  127 . 
     When starting the game in the game processing system  101 , the player  5  uses the information processing device  20  to start the chat mode. The process for executing the chat mode is performed by the chat mode execution unit  21   a  of the information processing device  20 . 
     When the mode switch condition is satisfied in the chat mode and the switch start object is selected, the mode switch process for switching to the VR mode is started. The mode switch process is performed by the switch processing unit  21   b . In the mode switch process, displaying the guidance corresponding to the above-described step S 31  is performed in the information processing device  20 . For example, a guidance prompting the player to put on the HMD  110  is displayed on the display  24  of the information processing device  20 . Displaying the switch object  86  corresponding to step S 32  and subsequent processes are executed in the HMD  110 . 
     When the VR mode is started, the processing of the VR mode is performed by the VR mode execution unit  21   c  of the HMD  110 . 
     According to the above embodiments, the following advantageous effects can be obtained. With the game processing system  1 ,  101 , it is possible to play a game in the first mode (for example, the chat mode) without using the HMD  10 . The game parameters such as the favorability updated in the first mode are used also in the second mode (for example, the VR mode). This makes it possible to play the game in the first mode when the HMD  10  is not usable and to play the game in the second mode when the HMD  10  is usable. 
     With the game processing system  1 ,  101 , the game parameters stored in the storage  27  are updated in accordance with progress of the game, and different scene are executed in accordance with the updated game parameters. 
     Embodiments of the present invention are not limited to the above embodiments but various modifications are possible within a spirit of the invention. For example, some or all of the functions executed by the computer processor  21  and the computer processor  121  may be realized by a computer processor which is not shown in the above-mentioned embodiment without departing from the scope of the invention. For example, the game processing system  1  and the game processing system  101  may include a game machine that executes at least a part of the game processing program. Some of the functions realized by processing of the computer processor  21  or the computer processor  121  may be realized by processing performed by the game machine. 
     Embodiments of the disclosure may include various devices and electronic components other than those described above. For example, in addition to the information processing device  20  and the HMD  10 ,  110 , the game processing system  1  and the game processing system  101  may be provided with a control device for receiving operations of the player  5 . The game processing system  1  and the game processing system  101  may detect operations of the player  5  via the control device and perform the processing of the game in accordance with the detected operations. 
     The procedures described herein, particularly those described with a flowchart, are susceptible of omission of part of the steps constituting the procedure, adding steps not explicitly included in the steps constituting the procedure, and/or reordering the steps. The procedure subjected to such omission, addition, or reordering is also included in the scope of the present invention unless diverged from the purport of the present invention.