Abstract:
A system and method are disclosed for ordered execution of actions in a game environment is disclosed. An indication of a first object having been targeted in the game environment may be received whereby the object is assigned a first target slot. An indication of a second object having been targeted in the game environment may then be received, this second targeted object being assigned a second target slot. An action is then executed in the game environment with respect to each of the targeted objects in response to a command from an input device. The execution of the action with respect to each of the targeted objects may occur in accordance with an order defined by the target slots.

Description:
CROSS-REFERENCE TO RELATED APPLICATIONS  
       [0001]     This application is a continuation and claims the priority benefit of U.S. patent application Ser. No. 09/773,452 entitled “Game Playing System with Assignable Attack Icons” and filed Jan. 31, 2001. This disclosure of this application is incorporated herein by reference. The application is related to U.S. patent application Ser. No. 11/375,296 entitled “Game Playing System with Assignable Attack Icons” and filed Mar. 13, 2006. 
     
    
     BACKGROUND OF THE INVENTION  
       [0002]     1. Field of the Invention  
         [0003]     The present invention relates generally to video games and, more particularly, to targeting and attacking of objects in a video game system.  
         [0004]     2. Description of the Related Art  
         [0005]     In a video game, a game player is commonly represented by a video game character that can move about a virtual environment displayed on a display screen. The game player typically controls the character&#39;s actions using a video game controller that includes a joystick and one or more buttons. In one common type of game, the character encounters various scenarios throughout the course of the game. Such scenarios could include a competition scenario where the character competes against an opponent or a combat scenario where the character is required to fight and conquer one or more threats or enemies. The enemies typically approach the character from one or more directions on the display screen and then attack the character. The player uses the video game control to move the character and cause the character to attack enemies or defend against the enemy attacks using a weapon.  
         [0006]     In order to engage an opponent or attack an enemy, the game player typically uses a joystick or direction button on the controller to maneuver the character so that the character is facing the enemy. The game player then presses a controller button, which is a button on the controller that causes the character to initiate an attack action, such as jabbing a sword or throwing a punch. The controller may include multiple controller buttons, each of which is associated with an attack action. Typically, a controller button is fixedly associated with an attack action. That is, when the player presses the button, the video game character always initiates the attack action regardless of whether the character is actually facing an enemy or even near an enemy.  
         [0007]     It can be appreciated that video game combat is simplest when there are few enemies present simultaneously on the display screen, thereby making it relatively easy for the game player to correctly maneuver the character into an attack position so that the attack action has an affect on the desired enemy. For example, if there is only one enemy on the display screen, the game player can concentrate attention on the single enemy. Consequently, the game player can orient the character to face that enemy and initiate an attack on the enemy with relative ease.  
         [0008]     However, as the number of enemies on the display screen increases, it becomes increasingly difficult for the player to attack specific enemies. The character may be surrounded by several enemies each of which moves about, making it difficult for the game player to correctly maneuver the character to face a specific enemy. The sheer number of enemies may also make it difficult for the game player to discern when the character is actually facing a specific enemy for attack. For example, if several enemies are grouped closely together, it may be unclear to the game player exactly which enemy the character is facing and, consequently, which enemy the character will attack upon pressing of the controller button. Unfortunately, this may result in the character initiating an attack on one enemy when the player actually intended to initiate an attack on a different enemy.  
         [0009]     Another problem associated with simultaneously confronting multiple enemies is that it becomes difficult for the game player to attack a succession of different enemies. Under the conventional attack method, the game player has to orient the character toward a first enemy and then attack that enemy. In order to subsequently attack a second enemy, the game player must first maneuver the character so that the character is facing the second enemy. This can become quite cumbersome for the player, particularly if the second enemy is located at an awkward position relative to the character, such as behind the character or at a distance removed from the character. This often results in the player fumbling with the joystick and losing an attack opportunity. The requirement of re-orienting the character to the second enemy also takes time, which can be detrimental in an action game where characters must successfully and quickly attack enemies with success or otherwise risk incurring damage from the enemies.  
         [0010]     The significance of the aforementioned problems only increases as the graphics processing power of video game systems increases. Modern video game systems are able to display and control an increasing number of enemy characters on the video game display at one time. Thus, it is becoming even more difficult and cumbersome for game players to target and attack specific enemies in a video game environment.  
         [0011]     One way of overcoming the difficulty in targeting and attacking enemies is to simply provide the video game character with a larger weapon having a relatively large attack range. A larger attack range increases the likelihood of a successful attack regardless of whether the character is correctly oriented to an enemy. Consequently, larger weapons provide the game player with a greater margin of error in orienting the character relative to an enemy. For example, if the character is equipped with a small sword with a small attack range, then the player may have to precisely orient the character relative to an enemy in order to successfully attack the enemy. However, if the character is equipped with a large battle axe, then the character need only swing the battle axe in the vicinity of the enemy and rely on the large range of the weapon to encompass the enemy.  
         [0012]     Unfortunately, such a solution results in a “hack and slash” combat scenario where the game player can disregard the video game character&#39;s orientation relative to an enemy. The player simply moves the character through a battle scene and wildly presses the controller button, hoping that the wide range of the resultant attacks will include a great number of enemies. While such hack and slash games can be fin, they are also simplistic and can result in the video game player quickly losing interest in the game. As game systems become more sophisticated, game players are demanding a richer and more realistic video game experience that both challenges the player and more closely simulates a real world scenario. Game players are also demanding an environment that provides greater opportunity to demonstrate game playing skills, such as showboating or using flourish or signature moves.  
         [0013]     In a real world combat situation, an experienced fighter surrounded by multiple enemies could quickly target a specific enemy for attack and then successfully initiate an attack on the enemy. Additionally, in a real world situation, an experienced fighter could initiate attacks even if the fighter were not facing the enemy. Consequently, it would enrich the video game experience to allow players to easily and quickly target and attack specific enemies in a combat scenario.  
       SUMMARY OF THE INVENTION  
       [0014]     In one exemplary embodiment of the present invention for method for ordered execution of actions in a game environment is disclosed. Through this method, an indication of a first object having been targeted in the game environment may be received. The first targeted object is assigned a first target slot. An indication of a second object having been targeted in the game environment is received; this second targeted object is assigned a second target slot. An action is then executed in the game environment with respect to each of the targeted objects in response to a command from an input device. The execution of the action with respect to each of the targeted objects may occur in accordance with an order defined by the target slots.  
         [0015]     A computer-readable medium is also disclosed as an exemplary embodiment of the present invention. The medium may comprise a program that when executed by the processor of a computing device causes the computing device to perform a method for ordered execution of actions in a game environment as described above.  
         [0016]     An exemplary system for ordered execution of actions in a game environment is disclosed herein. An embodiment of this exemplary system includes a controller interface coupled to an input control device. The input control device is configured to generate input control signals to manipulate actions in the game environment. A memory device and processor are also provided, the processor being coupled to the memory device and the controller interface. The processor is, in this exemplary embodiment, configured to receive input control signals from the input control device, the input control signals including instructions for the manipulation of a target interface displayed in the game environment. The processor is also configured to assign target slots to objects targeted through manipulation of the target interface in the game environment. The processor is still further configured to store information in the memory device, the information associating the assigned target slots with targeted objects. The processor is also configured to execute an action with respect to each of the targeted objects in response to a command received from the input control device. The execution of the action with respect to each of the targeted objects may occur in accordance with an order defined by the information in the memory device associating the assigned target slots with the targeted objects.  
         [0017]     Other features and advantages of the present invention should be apparent from the following description of the preferred embodiment, which illustrates, by way of example, the principles of the invention.  
     
    
     BRIEF DESCRIPTION OF THE DRAWINGS  
       [0018]      FIG. 1  is an illustration of a video game system constructed in accordance with the present invention.  
         [0019]      FIG. 2  is an illustration of a video game controller of the video game system illustrated in  FIG. 1 .  
         [0020]      FIG. 3  is a block diagram of a hardware configuration of the video game system.  
         [0021]      FIG. 4  is an illustration of a display screen produced by the video game system, showing a player character and several enemy characters.  
         [0022]      FIG. 5  is an illustration of several exemplary target range indicators that are displayed in association with a player character.  
         [0023]      FIG. 6  is a flow diagram that illustrates the processing steps executed by the video game system to allow a game player to target one or more enemies for attack.  
         [0024]      FIG. 7  is an illustration of a display screen produced by the video game system, showing a player character targeting an enemy character for attack and the corresponding controller actuation that would generate such targeting.  
         [0025]      FIG. 8  is an illustration of a display screen produced by the video game system, showing a player character targeting a pair of enemy characters for attack.  
         [0026]      FIG. 9  is a flow diagram that illustrates additional processing steps executed by the video game system to allow a game player to target one or more enemies for attack.  
         [0027]      FIG. 10  is an illustration of a display screen produced by the video game system, showing a player character targeting a subsequent enemy for attack.  
         [0028]      FIG. 11  is a flow diagram that illustrates the processing steps executed by the video game system to allow a game player to attack a targeted enemy.  
         [0029]      FIG. 12  is an illustration of a display screen produced by the video game system, showing a player character and a targeted enemy character in attack range.  
         [0030]      FIG. 13  is an illustration of a block diagram showing an exemplary software structure for implementing a targeting and attack scheme for a video game.  
     
    
     DETAILED DESCRIPTION  
       [0031]      FIG. 1  is a schematic illustration of an information processing or video game system  100 . The video game system  100  includes a video game main unit  110  and one or more controllers  120  that are communicatively coupled to the main unit  110  via respective controller interfaces  125  on the main unit  110 . The controllers  120  each comprise an input device for receiving user instructions.  
         [0032]     The video game system  100  interfaces with an audio-visual (AV) output device  135  that is communicatively coupled to the main unit  110 . The AV output device  135  includes a display screen  140  for displaying image data in accordance with signals received from the main unit  110 . The AV output device  135  also includes one or more sound speakers  145  for outputting audio data in accordance with signals received from the main unit  110 .  
         [0033]     The main unit includes a program reader  150  that is configured to receive a game program storage medium, such as such as a magnetic floppy disk, an optical CD-ROM disc, a CD-R disc, a CD-RW disc, a DVD disk, or the like. The game program storage medium is a recording medium for supplying an application program such as a video game to the main unit  110 . The main unit  110  is configured to process information and execute the program instructions located on the game program storage medium. The main unit  110  outputs image and sound data to the AV output device  135  in accordance with the program instructions. The main unit  110  receives user input from the controllers  120 , as described in more detail below.  
         [0034]      FIG. 2  is a detailed view of one of the controllers  120 . The controller  120  includes one or more user input interfaces, such as buttons and/or joysticks, that allow a user to input various game commands. The controller  120  transmits signals regarding the state of the input interfaces to the main unit  110 . For example, the controller  120  transmits a signal to the main unit  110  in response to actuation of the user input interfaces, such as pressing a button or moving a joystick on the controller  120 .  
         [0035]     The controller  120  preferably includes a start button  210  that allows a user to transmit a start command for a game program to the main unit  110 . A selection button  215  on the controller  120  allows the user to select various game modes using a menu displayed on the AV output device  135 . A mode selection button  220  can be used by the user to vary controller modes between digital and analog. An LED lamp  225  indicates a controller mode (analog or digital). The controller  120  also includes a left button  230  and a right button  235  that can be associated with inputs with respect to a game application.  
         [0036]     The controller  120  includes a first game operational input  240  and a second game operational input  245 . The second game operational input  245  preferably includes a plurality of controller buttons, including a first controller button  250 , a second controller button  255 , a third controller button  260 , and a fourth controller button  265 . Preferably, each controller button  250 ,  255 ,  260 ,  265  is associated with an identifier that may be used to identify and distinguish the controller buttons  250 ,  255 ,  260 ,  265 . The identifier could comprise a symbol that is labeled on or near the associated controller button. For example, the first controller button  250  is associated with a triangle symbol, the second controller button  255  is associated with a circle symbol, the third controller button  260  is associated with an X symbol, and the fourth controller button  265  is associated with a square symbol. Preferably each symbol to be associated with a controller button is labeled on or near the corresponding controller button.  
         [0037]     The controller  120  also includes first and second directional input interfaces, such as a first joystick  270  and a second joystick  275 . The first and second joysticks  270 ,  275  preferably comprise sticks that may be positioned in a neutral position or moved into a non-neutral position by moving the stick in a particular direction. Movement of the joysticks  270 ,  275  into a non-neutral position in a given direction preferably results in the controller  120  outputting a corresponding directional command to the main unit  110  in a digital format, causing a corresponding movement in the video game environment. It will be appreciated that the configuration of the controller  120  could be modified to include more or less user input interfaces and also to vary the locations of the input interfaces.  
         [0038]      FIG. 3  is a block diagram of an exemplary hardware configuration of the entertainment system shown in  FIG. 1 . The video game system  100  includes a central processing unit (CPU)  300  that is associated with a main memory  305 . The CPU  300  operates under control of programming steps that are stored in the OS-ROM  360  or transferred from a game program storage medium to the main memory  305 . The CPU  300  is configured to process information and execute instructions in accordance with the programming steps.  
         [0039]     The CPU  300  is communicatively coupled to an input/output processor (IOP)  320  via a dedicated bus  325 . The IOP  320  couples the CPU  300  to an OS ROM  360  comprised of a non-volatile memory that stores program instructions, such as an operating system. The instructions are preferably transferred to the CPU via the IOP  320  at start-up of the main unit  110 .  
         [0040]     The CPU  300  is communicatively coupled to a graphics processing unit (GPU)  310  via a dedicated bus  315 . The CPU  310  is a drawing processor th at is configured to perform drawing processes and formulate images in accordance with instructions received from the CPU  300 . For example, the CPU  310  may render a graphics image based on display lists that are generated by and received from the CPU  300 . The CPU may include a buffer for storing graphics data. The GPU  310  outputs images to the AV output device  135 .  
         [0041]     The IOP  320  controls the exchange of data among the CPU  300  and a plurality of peripheral components in accordance with instructions that are stored in an IOP memory  330 . The peripheral components may include one or more controllers  120 , a memory card  340 , a USB  345 , and an IEEE 1394 serial bus  350 . Additionally, a bus  355  is communicatively coupled to the IOP  320 . The bus  355  is linked to several additional components, including the OS ROM  360 , a sound processor unit (SPU)  365 , an optical disc control unit  375 , and a hard disk drive (HDD)  380 .  
         [0042]     The SPU  365  is configured to generate sounds, such as music, sound effects, and voices, in accordance with commands received from the CPU  300  and the IOP  320 . The SPU  365  may include a sound buffer in which waveform data is stored. The SPU  365  generates sound signals and transmits the signals to the speakers  145  ( FIG. 1 ).  
         [0043]     The disc control unit  375  is configured to control the program reader  150  ( FIG. 1 ), which can comprise, for example, an optical disk drive that accepts removable storage media such as a magnetic floppy disk, an optical CD-ROM disc, a CD-R disc, a CD-RW disc, a DVD disk, or the like.  
         [0044]     The memory card  340  may comprise a storage medium to which the CPU  300  may write and store data. Preferably, the memory card  340  can be inserted and removed from the IOP  320 . A user can store or save game data using the memory card  340 . In addition, the video game system  100  is preferably provided with at least one hard disk drive (HDD)  380  to which game data may be written and stored.  
         [0045]     A data I/O interface, such as an IEEE 1394 serial bus  350  or a universal serial bus (USB)  345  interface, is preferably communicatively coupled to the IOP  320  in order to allow data to be transferred into and out of the video game system  100 .  
         [0046]     The video game system  100  is configured to implement a game that is realized when the CPU  300  executes program instructions that are read from a program storage medium loaded in the main unit  110 .  FIG. 4  shows a video frame  405  of an image displayed on the display screen  140  of the AV output device  135  in the course of a combat scenario of the game. The image includes a portion of a game environment or virtual environment  410  that includes an initial object, such as a player character  415 , and one or more candidate objects, such as opponents or enemy characters  420 . The enemy characters can comprises other more abstract inanimate objects in the virtual environment  410 . The player character  415  comprises a character object that is controlled by a game player. The enemy characters  420  comprise objects that are controlled by the CPU  300  or by another game player and are candidates for designation and action relating to the initial object, as described below. The enemy characters  420  are antagonistic to the player character.  
         [0047]     For ease of illustration, the player character  415  is represented by a circle symbol and the enemy characters  420  are each represented by a cross symbol. However, in an actual game image the player character  415  and enemy characters  420  are preferably represented by images that resemble human, animal and/or monster anatomies.  
         [0048]     In accordance with one aspect of the invention, the game player can designate candidate objects, such as by targeting enemy characters  420  for attack. The game player can then cause a predetermined action from the initial object with respect to the candidate object, such as causing the player character  415  to initiate an attack on the targeted enemy characters. When a player character initiates an attack on an enemy character, the player character attempts to inflict damage or harm on the enemy character. A targeted enemy character  420  is an enemy character  420  that may be attacked by the player character  415  when a controller button associated with the targeted enemy character is pressed. When one character successfully attacks another character, the character that was attacked incurs damage. Other video game scenarios may involve the player character engaging the designated candidate objects.  
         [0049]     The targeting and attacking process generally proceeds as follows. First, one or more candidate objects comprised of enemy characters  420  may satisfy certain criteria for targeting such as being within a designation range, or target range, of the player character  415 . This is further described below. The CPU  300  then classifies the appropriate enemy character(s) as a target and associates a controller input interface, such as a controller button on the controller  120 , with the targeted enemy character(s). The game player can then actuate the input interface that is associated with the targeted enemy character, such as by pressing the controller button on the controller. In response to actuation of the input interface, the CPU  300  causes the player character to initiate an attack on the targeted enemy character. The player may be confident of a successful attack with a single actuation of the controller button if the targeted enemy is within an attack range of the player character. Advantageously, multiple enemies may be targeted at the same time. The game player can cause the enemy character to attack any targeted enemy character by actuating the controller button associated with the targeted enemy character.  
         [0050]     Preferably, the CPU  300  manages the player character  415  as a player object comprised of a data structure that contains a profile of the player character. The player object data structure preferably includes as data a character identifier, a mode identifier, weapon data, attribute data, location data, and movement speed data. The character identifier comprises a code for identifying the player character object. Preferably, the CPU  300  maintains a similar data structure for each enemy character  420 .  
         [0051]     The mode identifier identifies the current mode of the player character  415 . As described more fully below, the player character  415  can enter into a combat mode wherein the player character  415  can target and attack one or more enemy characters  420 .  
         [0052]     The active weapon data includes data regarding weapons that are available to the player character. The weapon data preferably includes a list of weapons that are in inventory as well as an identifier of a weapon for which the player character  415  is currently equipped. Preferably, the game player may equip the player character with a weapon using the controller  120 .  
         [0053]     The attribute data preferably relates to attributes of the player character, such as the player character&#39;s strength, vitality, dexterity, etc. Preferably, the attribute data also includes the current state of the character with respect to damage and fatigue.  
         [0054]     The location data preferably comprises data regarding the location of the player character in the virtual environment  410 . The location data may comprise coordinate data that indicates the location of the player character.  
         [0055]     The movement speed data is indicative of a speed at which the player character moves in response to the video game player commands. The video game player can preferably move the player character  415  around the virtual environment  410  by actuating an input interface on the controller  120 , such as by moving the first joystick  270  on the controller  120  ( FIG. 2 ). The player character  415  preferably moves in a direction that corresponds to the direction that the player moves the first joystick  270 . For example, the player character  415  preferably moves in an upward direction in the virtual environment when the game player moves the first joystick  270  in an upward direction. In another embodiment, the player character  415  moves in a frontward direction when the joystick  270  is moved upward. In another embodiment, the player character  415  moves in a direction that a first-person virtual camera is facing when the joystick  270  is moved upward.  
         [0056]     With reference to  FIG. 4 , the player character  415  preferably has a front face that points in a particular direction, as exhibited by the front face indicator  430 . In the illustrated embodiment, the front face indicator  430  comprises an arrow that shows which direction the player character is facing. However, the front face could also be indicated by the anatomy of the player character. For example, if the player character were in the shape of a human, then the front face could be indicated by a drawing rendition of a human having a face that points in a particular direction. When the game player moves the player character  415 , the front face is reoriented to face in the direction that the player character is being moved.  
         [0057]     As mentioned, the game player can preferably use the controller  120  to cause the player character  415  to enter into a combat mode. In combat mode, the game player can cause the player character  415  to initiate attacks on the enemy characters  410  and to defend against attacks initiated by the enemy characters  420 . The game player preferably initiates combat mode by actuating an input interface on the controller  120 , such as by moving the second joystick  275  ( FIG. 2 ) in a desired direction.  
         [0058]     When the second joystick  275  is moved away from a neutral position, a designation range indicator in the form of a target range indicator  440  is preferably displayed on the display screen  140 . The target range indicator  440  comprises a visual indication of a target range for the player character  415 . Preferably, the game player can target enemy characters  420  that enter or intersect the target range indicator  440  on the display screen. As mentioned, once an enemy character is targeted, the game player can cause the player character  415  to initiate an attack on the targeted enemy character by pressing a controller button that is associated with the enemy character. Preferably, the player character can successfully attack a targeted enemy character when the targeted enemy character is within the attack range of the player character&#39;s weapon.  
         [0059]     In one embodiment, the target range indicator  440  comprises a bounded area that extends a distance radially outward from a base  442 . The bounded area encompasses a predetermined region of the game environment shown on the display screen. The location of the base  442  preferably coincides with the location of the player character  415 . Thus, as the player character  415  moves in the game environment, the base  442  follows the movement of the player character  415 , with the target area  440  always extending radially outward from the base  442 . The target range indicator  440  could have various shapes that encompass a given area of the display screen. The target range indicator could also comprise a single line that extends outwardly from the base  442 .  
         [0060]     Preferably, a portion of the target range indicator  440  includes an attack range indicator  450  comprised of a visual indication of the range that a single player attack move will cover.  
         [0061]     When first activated, the target range indicator  440  preferably extends radially outward from the player character  415  in the direction that the joystick  275  has been moved. For example, in  FIG. 4  the target range indicator  440  extends to the left and downward from the player character  415 , which indicates that the game player moved the joystick  275  to the left and downward. The game player can change the orientation of the target range indicator  440  in two ways. First, the game player could return the joystick  275  to the neutral position, which preferably causes the target range indicator  440  to be removed from display. The game player could then move the joystick  275  in a different direction thereby causing the target range indicator  440  to be displayed along the new direction that the joystick  275  was moved.  
         [0062]     Alternately, the game player could re-orient the target range indicator by maintaining the joystick  275  in a nonneutral position and then sweeping the joystick  275  in a circle or a portion thereof. The target range indicator  440  preferably then moves in conjunction with movement of the joystick  275 . For example, if the game player sweeps the joystick  275  in a circular motion, the target range indicator  440  will sweep around the player character  415  in a circular motion. This type of movement of the target range indicator  440  is referred to herein as “sweeping” of the target range indicator  440 . The direction of the target range indicator  440  and the front face direction of the player character do not necessarily coincide with one another.  
         [0063]     In one embodiment, the size and shape of the target range indicator  440  is a function of the player character&#39;s attack capabilities. The player character&#39;s attack capabilities could vary depending on the weapon (if any) with which the player character  415  is equipped and the personal profile of the player character, such as the strength of the player character. In one embodiment, the current state of the player character, such as fatigue state or damage state, could also affect the size and shape of the target range indicator  440 .  
         [0064]     In one embodiment, the size of the target range indicator  440  depends solely on the attack capabilities of the weapon with which the player character is equipped. The attack capabilities of a weapon include the physical range of the weapon and the number of enemies that can be simultaneously attacked with the weapon. Each weapon preferably can damage a maximum number of enemies for a single swing or attack move of the weapon. Certain weapons may provide the player character the ability to attack several enemies with one swing or attack of the weapon. Preferably, the size and area covered by the target range indicator  440  increases as the attack capabilities of the weapon increase.  
         [0065]      FIG. 5  shows three examples of differently sized target range indicators  440 . The target range indicator  440   a  is for a sword weapon, the target range indicator  440   b  is for a taiaha weapon (which can attack more enemies at one time than a sword), and the target range indicator  440   c  is for an axe (which can attack even more enemies than a taiaha). The size of the target range indicator  440  varies as a function of the weapon. It will be appreciated that weapons named herein are exemplary and that the particular type of weapon could vary.  
         [0066]     As shown in  FIG. 5 , the attack range indicator  450  for each target range indicator  440  is sized to encompass up to a maximum number of enemy characters  420 . The number of enemy characters that fit within an attack range indicator indicates the attack capabilities of the corresponding weapon. For example, only one enemy character fits within the attack range indicator  450   a  for the sword. This indicates that the sword can only target one enemy character at a time. On the other hand, the attack range indicator  450   c  for the axe holds up to 6 enemy characters. This indicates that an axe can target a maximum of 9 enemy characters at one time (3 enemy characters per controller button). The attack range indicator  450   b  for the taiaha holds up to 6 enemy characters, indicating that the taiaha can target up to 6 enemy characters at once (2 enemy characters per attack button).  
         [0067]      FIG. 6  is a flow diagram that illustrates the computer operations by which the game player may target one or more enemies for attack by the player character  415 . In the first operation, represented by the flow diagram box numbered  605 , the game player actuates the joystick  275  on the controller  120 , such as by moving the joystick  275  in a particular direction. The CPU  300  detects that the joystick  275  has been actuated.  
         [0068]     In the next operation, represented by the flow diagram box numbered  610 , the CPU  300  causes the target range indicator  440  to be displayed in response to movement of the joystick  275 . As mentioned, the target range indicator  440  extends radially outward from the player character  415  in a direction that corresponds to the direction in which the joystick  275  was moved. With reference to  FIG. 7 , the joystick  275  on the controller  120  has been moved upward and to the left, as exhibited by the arrow protruding from the joystick  275 . Likewise, the target range indicator  440  also extends radially upward and to the left with respect to the player character  415 .  
         [0069]     A joystick is preferably used to activate the target range indicator  440  because a joystick allows the player to both activate the target range indicator  440  and specify a direction for the target range indicator  440  using a single input interface. However, it is envisioned that the game player could also activate the target range indicator  440  in other manners, such as by pressing a button on the controller  120  or by actuating a combination of input interfaces.  
         [0070]     In the next operation, represented by the flow diagram box numbered  615 , at least one enemy character  420   a  intersects at least a portion of the area covered by the target range indicator  440 . The CPU  300  could detect such intersection, for example, by monitoring the location coordinates of the enemy characters  420 . The CPU  300  could periodically compare the location coordinates of each enemy character  420  with respect to the area of the target range indicator  440 . The CPU  300  could then determine whether there is any overlap between an enemy location and the area encompassed by the target range indicator  440 .  
         [0071]     An enemy character  420  could come to intersect the target area  440  in several ways. In a first way, the game player could activate the target range indicator  440  so that it initially intersects an enemy character  420  by simply moving the joystick  275  in the direction of the enemy character  420 . The target range indicator  440  would thus initially be displayed in intersection with an enemy character  420 , such as is shown in  FIG. 7 .  
         [0072]     In another way, the game player could activate the target range indicator  440  so that it initially does not intersect with an enemy character  420 , such as is shown in  FIG. 4 . The game player could then sweep the target range indicator  440  using the joystick  275  to change the orientation of the target range indicator  440 . In this manner, the game player may cause the target range indicator  440  to intersect an enemy character  420  that is located along the sweep path of the target range indicator  440 .  
         [0073]     An enemy character  420  could also come to intersect the target range indicator  440  through movement of the location of the player character  415 , movement of the location of an enemy character  420 , or a combination thereof. For example, the game player could fix the position of the target range indicator  440  by holding the joystick  275  in a fixed position. The game player could then rely on the movement of an enemy character to bring the enemy character within the region of the target range indicator  440 . Advantageously, the various ways of intersecting the enemy characters with the target range indicator  440  adds a strategic facet to the game, as the game player could manually choose a specific enemy target or could rely on enemy movement to designate targets.  
         [0074]     The CPU  300  preferably maintains in memory one or more target slots that are used to keep track of targeted enemies. A target slot could comprise a memory location that can store the identifier codes of one or more enemies. When one or more enemy character  420  intersects the target range indicator  440 , the CPU  300  considers whether to assign the enemy characters  420  to a target slot. In one embodiment, the total number of target slots is less than or equal to the number of controller buttons on the controller  120 . In the illustrated example, there are 4 controller buttons  250 ,  255 ,  260 ,  265 , so there can be a maximum of 4 target slots available at one time. It will be appreciated that less than the total quantity of controller buttons  250 ,  255 ,  260 ,  265  could be used for attack and that any combination of the controller buttons  250 ,  255 ,  260 ,  265  could be used for attack.  
         [0075]     With reference again to  FIG. 6  the next operation is represented by the flow diagram decision box numbered  620 . After an enemy character  420  has intersected the target range indicator  440 , the CPU  300  determines whether any enemy characters  420  have already been targeted. That is, the CPU  300  determines whether any target slots have yet been assigned to an enemy character  420 . If the CPU  300  determines that at least one target slot is already filled, then the CPU  300  proceeds to the operation described in the flow diagram of  FIG. 9 , as represented by the flow diagram box numbered  625 . The flow diagram of  FIG. 9  is described in more detail below.  
         [0076]     However, if no enemy characters  420  have yet been targeted, then in the next operation, the CPU  300  targets the enemy character  420   a  by assigning the enemy character  420   a  to a first target slot. This is represented by the flow diagram box  627 . This could be accomplished, for example, by the CPU  300  writing the identifier code for the enemy character  420   a  to a predetermined memory location that is associated with the first target slot.  
         [0077]     It is possible that plural enemy characters  420  may simultaneously intersect the target range indicator  440 . If multiple enemies simultaneously intersect the target range indicator  440 , then the CPU  300  can assign multiple enemy characters  420  to the same target slot as a group. The maximum number of enemy characters  420  that can be assigned to a single target slot is preferably limited by the attack capability of the player character&#39;s weapon. For example, if the player character  420  is using a sword, then only one enemy character  420  can be assigned to a target slot even if more than one enemy character  420  is intersecting the target range indicator  440 . This is because the sword can only attack one enemy character  420  at one time. However, if the player character  415  is using the taiaha, then more than one enemy character  420  can be assigned to a target slot as long as the enemy characters  420  are simultaneously intersecting the target range indicator  440 .  
         [0078]     An example of this situation is shown in  FIG. 8 , where a pair of enemy characters  420   a  and  420   b  are located at least partially within the area encompassed by the target range indicator  440 . If the player character is using the taiaha, then both enemy characters  420   a  and  420   b  will be assigned to the same target slot as the taiaha can assign up to two enemy characters at once to a controller button. However, if the player were using the sword, then only one enemy character  420  would be assigned to the target slot. Preferably, the CPU  300  first assigns target slots to the enemy characters  420  that are nearest the player character  415 . The game player could sweep the target range indicator  440  to include multiple enemy characters  420 .  
         [0079]     In the next operation, represented by the flow diagram box numbered  630 , the CPU  300  associates the enemy(s) in the first target slot with one of the controller buttons  250 ,  255 ,  260 , or  265 . This may be accomplished, for example, by the CPU  300  writing the enemy character identifier codes to a memory location that is associated with a particular controller button. As described below with respect to  FIG. 11 , the game player can then cause the player character  415  to attack an enemy character by pressing the controller button that is associated with the enemy character.  
         [0080]     Preferably, the target slots are associated to the controller buttons  250 ,  255 ,  260 ,  265  according to a predetermined hierarchy. That is, the target slots are always associated to the controller buttons  250 ,  255 ,  260 ,  265  in a predetermined order. For the controller  120  shown in  FIG. 2 , the first controller button  250  is the first in the order, the second controller button  255  is the second in the order, the third controller button is the third in the order, and the fourth controller button  265  is the last in the order. It will be appreciated that the order of priority may be varied and that the number of controller buttons that are used for attacking could also be varied.  
         [0081]     In the next operation, represented by the flow diagram box numbered  635 , the CPU  300  causes a visual controller button indication to be displayed in association with the targeted enemy character  420   a . The visual controller button indication provides the game player with an indication of which controller button has been associated with the targeted enemy character. The visual indication could be anything that indicates to the player that an enemy character is targeted and that also indicates the associated controller button to the player. For example, the visual indication could comprise the targeted enemy character changing color or glowing in a color that corresponds to the color of a controller button.  
         [0082]     In one embodiment, the visual indication comprises an attack icon  710  comprised of a symbol that is associated with or identifies a controller button  250 ,  255 ,  260 , or  265 . Preferably, the game player can look at the attack icon  710  and easily identify which controller button  250 ,  255 ,  260 , or  265  is associated with the attack icon  710 . Preferably, the attack icon  710  is visually similar or identical to the identifier that is labeled on the controller button that was associated with the recently targeted enemy character  420   a . In the example shown in  FIG. 7 , the first controller button  250  shown in  FIG. 2  is associated with the targeted enemy character  420   a . The first controller button  250  has a triangle for an identifier symbol. Thus, the attack icon  710  also comprises a triangle. If a group of enemy characters  420  are in the same target slot, then the attack icon  710  is displayed over each targeted enemy character in the group. Thus, in  FIG. 8 , the triangle attack icon  710  appears over enemy characters  420   a  and  420   b . It will be appreciated that the attack icon could comprise any symbol that will help the user to identify which controller button has been associated with a targeted enemy character.  
         [0083]     With reference again to  FIG. 6 , in the next operation, represented by the flow diagram box numbered  640 , the CPU  300  reorients the player character  415  to face toward the recently-targeted enemy character  420   a . An example of this is shown in  FIG. 7 , where the front face indicator  430  points toward the recently targeted enemy character  420   a . This indicates that the player character  415  is now facing the enemy character  420   a . If a group of enemy characters  420  has been targeted, then the player character  415  preferably faces the nearest enemy character  420  in the group. Alternately, the player character  415  could face toward a predetermined location with respect to the group, such as the center point of the group. The operation then ends.  
         [0084]     As discussed above, the flow diagram shown in  FIG. 9  describes the computer operations that are performed in the situation where at least one target slot is already filled and the user attempts to target an additional enemy. In the first operation, represented by the flow diagram box numbered  900 , the CPU  300  determines whether any target slots are available. A target slot is available if it is not already filled with an identifier code for an enemy character. If there are not any target slots available, this indicates that all target slots have already been filled with enemies.  
         [0085]     If this is the case, the CPU  300  then proceeds to the next operation, represented by the flow diagram box numbered  905 . In this operation, the enemy  920   a  is not assigned to a target slot. Rather, the game player must wait until a target slot is free before another enemy can be targeted. Preferably, there are several ways that an assigned target slot can be freed for reassignment. One way is for the enemy character to be killed, such as a result of an attack by the player character  415 . A target slot may also be freed if the enemy character moves a predetermined distance away from the player character. If a group of enemy characters are assigned to one target slot, then the CPU  300  must removed all the enemy characters in the group from the target slot before the target slot is classified as free. Thus, all of the enemy characters would have to be killed or moved away from the player character the predetermined distance. When all enemy characters  420  have been removed from a target slot, then the target slot and the associated controller button are free for reassignment.  
         [0086]     If the CPU  300  determines that there are indeed target slots available, then the CPU  300  proceeds to the next operation, represented by the flow diagram box numbered  910 . In this operation, the CPU  300  targets the enemy character by assigning the enemy character to the next available target slot. This is described with reference to  FIG. 10 .  FIG. 10  shows that a second enemy character  420   b  has intersected the target range indicator  440 . Furthermore, at least one other enemy character, enemy character  420   a , has already been targeted, as indicated by the attack icon  710   a  over the enemy character  420   a . In this example, the CPU  300  would assign the enemy character  420   b  to the next available target slot.  
         [0087]     With reference again to  FIG. 9 , in the next operation, represented by the flow diagram box numbered  915 , the CPU  300  associates the targeted enemy(s) in the recently-filled target slot with one of the controller buttons  250 ,  255 ,  260 , or  265  according to the aforementioned priority order. In the example shown in  FIG. 10 , only the first controller button  250  has been associated with an enemy and controller buttons  255 ,  260 , and  265  are free. The second controller button  255  is thus the next available controller button in the priority order. Thus, the CPU  300  associates the targeted enemy character  420   b  with the second controller button  255 . If the second controller button  255  had already been associated with an enemy character  420 , then the CPU  300  would have associated the enemy character  420   b  with the next available controller button in the priority order.  
         [0088]     In the next operation, represented by the flow diagram box numbered  920 , the CPU  300  causes an attack icon  710   b  associated with the second controller button  255  to be displayed over the targeted enemy character  420   b . In the case shown in  FIG. 10 , the second controller button  255  was associated with the targeted enemy character  420   b . The second controller button  255  has a circle for an identifier symbol. Thus, the attack icon  710   b  is in the shape of a circle. The operation then ends.  
         [0089]      FIG. 11  shows a flow diagram that illustrates the computer operations by which the game player may cause the player character to attack a target enemy. The process is further described with respect to  FIG. 12 , where there is illustrated a player character  415  and several enemy characters  420 , including two targeted enemy characters  420   a  and  420   b  that are associated with the first controller button  250  and the fourth controller button  265 , respectively.  
         [0090]     In the first operation, represented by the flow diagram box numbered  1105 , the CPU  300  detects that the game player actuates an input interface that is associated with a targeted enemy  420 . For example, with respect to  FIG. 12 , the game player could press either the first controller button  250 , which is associated with the targeted enemy character  420   a , or the fourth controller button  265 , which is associated with the targeted enemy character  420   b.    
         [0091]     In the next operation, represented by flow decision box numbered  1110 , the CPU  300  determines whether the targeted enemy is in range for attack. As mentioned, the player character  420  uses weapons that each have a particular attack capability, including an attack range. If the targeted enemy character is not within the player character&#39;s attack range, the CPU  300  causes the player character to face the targeted enemy character without initiating an attack. This operation is represented by the flow diagram box numbered  1115 . In the example shown in  FIG. 12 , this would correspond to the game player pressing the first controller button  250 , which is associated with the targeted enemy character  420   a . The front face indicator  430  points toward the enemy character  420   a , indicating that the player character  415  is facing the enemy character  420   a . The enemy character  420   a  is presumed to be out of the player character&#39;s attack range.  
         [0092]     However, if a targeted enemy character is within range, then pressing of the controller button associated with the targeted enemy character causes the player character to attack the targeted enemy character. This is represented by the flow diagram box numbered  1120  in  FIG. 11 . With reference to  FIG. 12 , this would correspond to the game player pressing the fourth controller button  265 , which is associated with the targeted enemy character  420   b . If the game player presses the fourth controller button, then the player character  415  will initiate an attack on the enemy character  420   b . The enemy character  420   b  is assumed to be within the player character&#39;s attack range.  
         [0093]     Advantageously, the player character does not need to be facing an enemy character in order to attack an enemy character. Preferably, the player character can initiate attacks on enemy characters even when not facing the enemy character. For example, the player character could initiate a behind-the-back sword swing on an enemy character located behind the player character, or a sideways swing on an enemy character to the side. In such a case, the CPU  300  would initiate an animation wherein the player character attacks the enemy character while not facing the enemy character. This advantageously increases the number of available attack moves, which increases enjoyability of the game. It also makes it easier for a game player to attack specific enemy characters. The game player can cause the player character to attack any targeted enemy character by simply pressing the controller button associated with the target, regardless of whether the player character is actually facing the enemy character. Preferably, after the first attack is initiated on an enemy character, the CPU  300  causes the player character to turn and face the enemy character, as represented by the flow diagram box numbered  1115 .  
         [0094]     The game player can preferably cause the player character to initiate special attacks by pressing a combination of buttons on the controller. In one embodiment, the game player uses the unassigned controller buttons, if any, to initiate special attacks. For example, in  FIG. 12 , the second and third controller buttons  255 ,  260  are not associated with any targets. If the game player presses one of the unassigned buttons immediately after pressing an assigned controller button, then the CPU  300  causes the player character to initiate a special attack on the targeted enemy character. A special attack could comprise a combination of attack moves or one or more unique attack moves. For example, a particular player character could have a special signature move that is unique to the player character, such as a unique swing or flourish move.  
         [0095]     If the game player presses a controller button that is associated with a group of player characters, then the player character preferably attempts to attack as many of the enemy characters in the group as possible. For example, if the player character is using a taiaha, then the player character attempts to attack the maximum number of enemy characters that can be attacked with a taiaha. The game player can maneuver the player character into a location that will maximize the attack range.  
         [0096]     In addition to providing an indication of the associated controller button, the attack icon  710  ( FIG. 7 ) preferably provides status indications to the game player. The CPU  300  preferably causes the attack icon for an enemy to change visual state in response to the status of an enemy character. Preferably, an enemy character&#39;s attack icon  710  is in a first visual state, such as in a brightened state, when the enemy character is in range to be attacked by the player character. The attack icon  710  changes to a second visual state, such as a semitransparent state, if the associated enemy target is out of range of attack for the player character. The attack icon could also change to a third visual state, such as a flashing state, when the associated enemy target is close enough to be hit but will be missed if attacked. In one embodiment, the attack icon changes to the flashing state to indicate that the enemy is about to be de-targeted, such as when the enemy character is about to die or if the enemy character is about to move out of attack range.  
         [0097]      FIG. 13  is a block diagram that shows an exemplary software structure for implementing the game program described herein. A virtual environment data base  1305  stores data that describes the virtual environment. The virtual environment could be a finite, two-dimensional space that is managed as an X-Y coordinate system. Thus, any position in the virtual environment can be specified in the form of coordinates (x,y). The virtual environment could be divided into one or more blocks, wherein each block has a set of attributes that describe a portion of the virtual environment. The attributes could determine geographical information of the virtual environment and could comprise code for expressing a road, a river, a hill, a forest, etc. The blocks could also include image data for creating an image associated with the block.  
         [0098]     The software structure also includes an image forming module  1310  that communicates with the virtual environment database  1305 . The image forming module  1310  provides position and color information for the GPU.  
         [0099]     An operation receiving module  1315  communicates with the controller  120 . The operation receiving module  1315  accepts signals from the controller  120  regarding the states of the input interfaces on the controller  120 . The operation receiving module  1315  determines an action of the player character in accordance with the game player actuating the controller  120 . The operation receiving module  1315  determines movement direction of the player character through the virtual environment and also determines when the player character should initiate attacks. The movement directions of the joysticks  270  are preferably made to correspond to corresponding movements of the player character. The operation receiving module  1315  preferably also determines when the target range indicator  440  should be displayed in response to actuation of an input interface on the controller  120 .  
         [0100]     A player position calculation module  1320  performs a process for calculating the position and movement of the player character in the virtual environment. In response to signals from the operation receiving module  1315 , the player position calculation module  1325  periodically calculates the position of the player character with respect to a previous position in the virtual environment. The player position calculation module  1315  then determines a movement direction for the player character.  
         [0101]     A display control module  1330  accepts image information, such as position and color information, from the image forming module  1310  and the player position calculation module  1320  and then forwards rendering instructions to the GPU for processing.  
         [0102]     The software structure also includes an enemy control module  1335  that maintains the position of each enemy character. The enemy control module  1335  also controls movement of the enemy characters through the virtual environment.  
         [0103]     The present invention has been described above in terms of a presently preferred embodiment so that an understanding of the present invention can be conveyed. There are, however, many configurations for entertainment systems not specifically described herein but with which the present invention is applicable. The present invention should therefore not be seen as limited to the particular embodiments described herein, but rather, it should be understood that the present invention has wide applicability with respect to entertainment systems and video games generally. All modifications, variations, or equivalent arrangements and implementations that are within the scope of the attached claims should therefore be considered within the scope of the invention.