GB2118809A - Self-adjusting game difficulty method and apparatus for electronic games - Google Patents

Abstract

Video game apparatus is provided with an electrically alterable read- only-memory (EAROM) for storing digital information that is indicative of, among other things, game-play difficulty averaged over a successive number of the games played. During the intervening time between each game played, information indicative of the skill of the player engaging in the immediately preceding game is merged with the average skill-level data. The average skill level data is compared to a predetermined skill parameter and, depending upon the outcome of that comparison, game play difficulty parameters are selected accordingly. The averaged difficulty information is then returned to the EAROM where it remains until later use or resetting. Stored in the EAROM, it remains involatile, despite loss of power to the overall system, whether inadvertent or intentional. The player can select by switches (20) the degree of difficulty relative to the current standard stored in the EAROM (42). <IMAGE>

Description

SPECIFICATION Self-adjusting game difficulty method and apparatus for electronic games The present invention is directed generally to electronic game apparatus and, more particularly, to a video game capable of automatic adjustment of the difficulty with which the game is played.

Background of the invention Relatively recent advances in the electronic arts, particularly in the area of development of microprocessors, have been a major impetus in the creation and growth of the electronic game industry. Today, thanks to the availability of lowcost microprocessors and associated electronics, one encounters the products of this industry, not only in the home entertainment field, but to an ever increasing extent in the public entertainment sector in the form of coin-operated electronic games such as, for example, video games.

Witness: No longer are coin-operated electronic games found only in arcades; they can also be found in restaurants, drug stores, grocery stores, and similar places of public gathering.

It is desirable that coin-operated electronic game apparatus be challenging and entertaining for as long as possible. A coin-operated game that can maintain an appropriate level of difficulty can continuously challenge the player provide many hours of entertainment. Unfortunately, as players skill levels increase with experience, coinoperated games that, were initially appealing and challenging, become less difficult and, therefore, less challenging thereby losing their appeal.

Conversely, if a new electronic game is too difficult to play at the outset, it may be by-passed for other not so challenging entertainment.

Thus, those who own and provide coinoperated games for public use are desirous of somehow striking a happy medium: A new game, when first introduced to the public, should be challenging but not too challenging; over its useful lifetime the game's challenge should not deteriorate (at least not too quickly) as the skill level of the player correspondingly increases.

Assuming that some method is available for adjusting the game's difficulty and/or challenge in relation to the variance in skill levels of the game's players, there remains the added problem of maintaining the information developed from preceding game play, information that is used to select game play parameters that increase or decrease difficulty. One approach, of course, is to utilize electronically readable, operator selectable switches that allow the operator to select gameplay parameters. This approach, however, requires the operator to monitor the game's use to somehow determine the average skill level of those playing the game, and then to interrupt game play, if necessary, to readjust game difficulty.

Summary of the invention The present invention provides a method and apparatus for game difficulty self-adjustment by an electronic game. Broadly, the method of the preferred embodiment of the present invention includes steps of (1) determining a value indicative of the skill with which the game has been played; (2) comparing the determined player skill with an operator-selected game-play skill level standard; and, in response to such comparison, (3) determining game-play operating parameters which adjust the level of difficulty of game play.

The preferred embodiment of the invention is used to provide self-adjusting difficulty capability to a microprocessor-based, coin-operated video.

Typically, coin-operated video games are adapted to present an ever increasing degree of difficulty to the player. Accordingly, the skill level with which the game is played is measured by the time each game lasts. Accordingly, the time of each game-play is determined and a weighted average is derived from the preceding game-piays. This weighted average becomes the determined player skill value that is compared to the operatorselected standard. If the comparison is greater than the selected standard, game operating parameters are changed to cause succeeding game-plays to be more difficult to play.

Conversely, if the selected standard is greater than the determined player skill level indicating that the game may be too difficult (and, therefore, possibly intimidating), the game operating parameters are changed to make subsequent play less difficult.

Apparatus used to implement the method of the invention includes option switches for allowing an operator to select the standard average game time, the game's controlling electronics, i.e., the microprocessor, for reading the option switches and performing the necessary computations and counter circuitry for generating a timing signal that provides a bench mark from which passages of time, such as the time the game is played, can be measured. In addition, since it is important that the determined average be maintained for long periods of time (i.e., months-on-end) despite power interruptions (whether intentional or not), non-volatile memory that can be electrically altered by the microprocessor is used as a storage element for the accumulated average that forms the determined player skill level value.In the preferred embodiment the storage element used is an electronically alterable read-only-memory (EAROM). The EAROM ailows the game's selfadjusting capability to be involatile, despite possible momentary or longer power interruptions.

Certain of the advantages of the present invention should now be evident. The invention obviates the need to reset skill determining parameters each time power is removed (for example, overnight). Nor is it necessary for the operator to constantly monitor the game in order to determine whether the game-play is becoming less difficult to play and, therefore, less challenging, causing a loss of appeal and (in coin operated games) profit potential; or that is not too difficult to play, again resulting in loss of appeal and profit, this time because of the intimidating effect of a game that is too difficult to play.The operator of a game incorporating the present invention is relieved of these supervisory duties, and can be confident that the game's inherent self-adjusting capability will provide a challenge that adjusts to the skill of those playing the game, a challenge that cannot be defeated by power interruption or similar catastrophes.

These are just a few objects and advantages obtained from the present invention.

Further such objects and advantages will be readily evident from a reading of the following detailed description of the invention, which should be taken in conjunction with the drawings.

The scope of the present invention is set forth in the appended claims.

Brief description of the drawings Fig. 1 is a perspective view of a video game that utilizes the method and apparatus of the present invention; Fig. 2 schematically represents, in simplified block diagram form, the electronic circuitry used in operation of the game of Fig. 1, and incorporating the apparatus that implements the present invention; Fig. 3 is a table illustrating parameters that are selected by the option switches shown in Fig. 2 that establish the operator-selected standard indicative of a level of game-play difficulty against which the determined player skill level value is compared; Fig. 4 is a flow diagram that illustrates that portion of each pre-game initialization subroutine that incorporates one part of the method of the present invention;; Fig. 5 is a flow diagram illustrating the end-ofgame subroutine that implements the second portion of the method of the present invention.

Detailed description of the invention Fig. 1 illustrates a video game, generally designated with the reference numeral 10, incorporating the present invention. The video game 10 is shown as including a game cabinet 12 that houses display screen 14, controls, including a gimble joystick 1 6 and start button 17, and, in the interior of the cabinet 12, the operating electronics of the video game including a circuit board 1 8 which carries operator selectable option switches 20.

The video game 10, known to the public as RED BARON (a trademark of the assignee of the invention, Atari, Inc.), is a one-player video game that presents, on the display screen 14, a first persons's view from a World War I bi-plane cockpit. Display objects, in the form of enemy biplanes, blimps, tanks, pill boxes, and the like, are generated on the video screen 14 by what is known in this art as X-Y or vector generator technique. The object of the game is to destroy as many of the enemy objects (i.e., the bi-planes, blimps, tanks, pill boxes, etc) as possible while maneuvering over and around a terrain that includes pyramids and buildings.Players maneuver their "bi-plane" utilizing the joystick control 16 which can be moved by a player in four directions (forward, backward, left and right) to create a sensation of diving, climbing, or banking to the left or right.

The video game 10 is coin-operated. Gameplay is initiated by a player when an appropriate coin is inserted in a coin slot (not shown) of the video game 10 and the start button 1 7 depressed.

Enemy objects are shot down or otherwise destroyed by operation of a finger-depressable firing button 1 6a located on the joystick 1 6.

"Hits" of enemy/objects provides points which accumulate as game-play progresses. However, the enemy objects possess the ability of returning fire, so that the player bi-plane can be destroyed-either by enemy fire or a miscalculation of maneuver, causing the player biplane to hit an object (i.e., building, mountains or other part of terrain, and the like). Accordingly, a player begins game-play with a certain predetermined number of "lives" (i.e., bi-planes) selectable by the operator. Additional lives (biplanes) can be granted a player during game-play when predetermined point accumulations are reached.

It can be seen that the time of each game played depends in large part on the player's skill vis-a-vis the difficulty of the video game 10. The skill level of the video game 10, in turn, is established by such operating parameters as the speed of movement of the objects viewed on the display screen 14 (representing, for example, the relative speed of the player's bi-plane and enemy objects) or the size of the displayed objects. The skill with which any particular game-play is played can be measured by the time it took for the game-play. This game-play time can be compared to a predetermined standard to determine if the game-play took too long (indicating a low-level of required skill to play the game) or was not long enough (indicating, perhaps. that the game may be too difficult).

The option switches 20 (in the form of twoposition, finger-actuatable switches SW1 -SWN) provide an operator with the capability of selecting one of a number of time values that represent particular skill level standards of gameplay. Compared to this operator-selected standard is a player skill level value that has been determined from previous game-play operation in the form of a weighted average of the times it took a player or players to play a number of preceding games. If this weighted average exceeds the operator-selected standard value, the microprocessor will change game parameters to cause the play to be more difficult.

Alternately, if the selected standard value is greater, game parameters will be changed to cause game-play to be less difficult. In essence, this self-adjusting feature determines what game parameters will be used for future operation of the video game 10, based on past operation, to establish a level of difficulty appropriate to the average skill of the players as their skill level improves.

Referring now to Fig. 2, the controlling electronics of the video game 10 (Fig. 1), including that portion used to implement the present invention, is illustrated in block diagram form. As shown, the video game 10 includes a microprocessor unit (MPU) 30 of the type having nonmaskable interrupt (NMI) capability, for performing the computational operations necessary for controlling game-play. The MPU 30 is coupled to an input/output (I/O) interface unit 32, a video signal generator 34, a memory system 36, including a program memory 38 in the form of a read-only-memory (ROM) and a working memory 40 in the form of a random-access-memory (RAM), and an electronically alterable read-onlymemory (EAROM) 42.Interconnection between the MPU 30 and the other units of the system with which the MPU 30 communicates is implemented by a 16-bit address bus 44 and an 8 bit data bus 46.

The I/O interface unit 32 receives input information from the option switches 20 (i.e., twoposition switches SW1-SWN) and the player input controls (i.e., joystick 1 6 and firing button 1 6a for assembly and ultimate communication via the data bus 46 to the MPU 30. In addition, the I/O interface unit receives and formats information generated by the MPU 30 for ultimate communication to various player outputs such as, for example, display illuminants (not shown) and an audio output (not shown) for providing sound.

The video signal generator 34 receives instructions and data from the MPU 30 to generate video signals that are appropriately formatted for transmission to a display unit 50 via a communicating link 52 along with other control signals. The received video and control signals generated by the video signal generator 34 are used by the display unit 50 to drive an electron beam that creates the symbols and objects of the game on the display screen 14 (Fig. 1).

The memory system 36 includes the program memory (ROM) 38 that contains, in sequential order, the program instructions utilized by the MPU 30 to operate the game. In addition, the memory system 36 includes the working memory (RAM) 40 that is accessible to the MPU 30 for temporary storage of various game parameters as they are generated during the continuation of the program and game play.

The EAROM 42 is non-volatile, and capable of retaining stored information despite a loss of power. Yet, EAROM 42 is available to the MPU 30 for both read and write operations. EAROM 42 is an element that is commercially available today from the General Instruments Corporation, Micro electronics Division, of Hicksville, New York, and is identified by part No. ER2055.

Synchronous operation is established by a clock generator 60 which, although not specifically shown, includes an oscillator circuit for providing a basic 12 megahertz (MHz) square wave clock signal. The clock generator 60 also includes a variety of counter circuits (not shown) for receiving the 12 MHz clock signal and for generating therefrom lower frequency signals.

Thus, for example, a microprocessor clock (MCLK) of 1.5 MHz is provided by the clock generator 60 and applied to the clock (CK) input of the MPU 30 by signal line 62; a 3 kilahertz (KHz) counter clock (CCLK) is provided by the clock generator 60 and conducted to the clock (CK) input of an NMI counter 64 by a signal line 66. In turn, the NMI counter 64 produces a 250 hertz interrupt clock (ICLK) that is conducted by a signal line 68 to the NMI input of the MPU 30. The clock generator 60 also provides a system clock signal that is communicated to its destination by the signal line 70.

In addition to the game program, there is stored in the program memory 38 sixteen (16) data words, each indicative of a predetermined skill level of game-play in terms of the time it would take to play 32 games on the video game 10. These times, illustrated in Table I of Fig. 3 as being T1-T16, are operator selectable through the medium of switch settings of option switches 20. Thus, as Fig. 3 illustrates, the operator may determine that an average time T7 is to be used as the desired operator-selected standard. Accordingly, the operator will make the appropriate switch setting of option switches 20 by closing switches SW2 and SW6. Switches SW1, SW3-SW5, and SW7 will remain or are placed in an open or deselected position.As Fig. 3 indicates, switches SW1-SW7 perform other functions: Switches SW1-SW3 set the point accumulation which, when exceeded during any one game-play, will grant a bonus airplane (i.e., one additional life) to the player; switches SW4 SW7 specify how many airplanes per game-play a player is to have.

Assume that an operator desires that video game 10 have a skill level corresponding to an average game time indicated by the average time T7. Accordingly, the operator will place the switches SW2 and SW6 in their selected position and the remaining switches (SW1, SW3-SW5 and SW7) in a deselected position. During an operator initiated initialization routine, the EAROM 42 is "seeded" by the MPU 30 in the following manner: The option switches 20 are read by the MPU 30 via the I/O interface unit 32.

The information obtained from switches SW1 SW7 are used to form a "pointer" address of a memory location in the program memory 38 at which the data word (of the 1 6 data words hereinbefore mentioned) indicative of desired operator-selected standard (here, time T7) is stored. The MPU 30 accesses the desired time information from the program memory 38 and stores it at a predetermined location in the EAROM 42.

Thus, the time T7 initially selected by the operator serves as an initial determined player skill level value for the self-adjusting difficulty capability of the invention. The operator, therefore, has the option of selecting an intial level of game-play of difficulty and manually resetting such difficulty if the game's difficulty adjustment capability is deemed too slow.

Thereafter, the selected initial determined player skill level value is automatically modified, as will be seen below, to ultimately become representative of a true determined player skill level.

The method of the present invention is performed in two parts, as indicated in Figs. 4 and 5. A first part of the method (Fig. 4) precedes each game played, and is used to calculate gameplay parameters in response to the operatorselected standard (which is indicative of a desired level of difficulty, represented by the selected time T7, for example) and the weighted average of preceding game plays. The second part of the method, illustrated in Fig. 5, recalculates the weighted average, using the time the system has determined it took to play the just completed game. The recalculated weighted average is than stored in the EAROM 42 for subsequent use in calculating game play parameters for the next game.

Turning now to specifics, that portion of the method used to provide the video game 10 with self-adjusting capability, illustrated in Fig. 4, is performed in the following manner: When a player initiates game-play operation of the video game 10, a "NEW GAME SUBROUTINE" is entered at 60. A portion of this subroutine contains steps 62-72, beginning with the step (at 62) of accessing the weighted average gameplay time value (T) from the EAROM 42. It should be evident that if the EAROM 42 was initially seeded with a-selected time value T7 (as described above) and no game-plays have been initiated, the accessed value T would be T7 (i.e., the weighted average is initially set equal to the one time standard, a value corresponding to the desired average game time).On the other hand, if the video game 10 has been played since EAROM 42 was seeded with the T7 value, the accessed value Twill quite probably be some other value.

Next, as indicated at 64, the MPU 30 (1) reads the "pointer" address by sampling the option switches 20 (i.e., switches SW1-SW7) and (2) uses the switch settings to form a memory address of program memory 38 to access (at 66) the desired time standard T7.

At 68 and 70 of Fig. 4 the values T and T7 are compared to one another. If the comparison at step 68 shows that T is greater than T7, an indication that the game has become easier to play (by taking longer to play), game parameters are calculated and used during game-play that increase the speed of movement of display objects on the display screen 14. The amount of speed increases are determined by the amount that T is greater than T7; that is, the difference between T and T7 is used as a starting point in calculating game parameters to be used.On the other hand if the comparison at 68 is negative (i.e., T is not greater than T7) but the comparison at 70 finds the accumulated average T to be less than the operator-selected standard T7, indicating that the clientele finds the game more difficult than expected, the game parameter calculations will produce game parameters that will slow down game-play, depending upon the amount of the difference. Thus, the comparison results of steps 68 and 70 result in a determination of the speed of movement game parameter used by the MPU 30 to cause the level of difficulty of the upcoming game-play to be commensurate with the difference, if any, between the skill with which video game 10 has been played and the game difficulty selected by the operator.

The determined player skill level, i.e., the weighted average T, is recalculated at the conclusion of each game-play during the END OF GAME SUBROUTINE 80 (Fig. 5). During gameplay, the MPU 30, in addition to its game control and operation activities, monitors the time it took to play the game, utilizing as a benchmark the 250 Hz ICLK received at its NMI input and provided by the NM counter 64 (Fig. 1). In effect, the MPU 30 counts each pulse received in its NMI input during game-play. At the end of each gameplay, the MPU 30 has (in a register-not shown) an accumulated count that is representative of the time the just-completed game took to play. At 82 the weighted average, T, is accessed from the EAROM 42.At 84 the MPU 30 calculates a new weighted average game play value T using the formuia: TneW=TT/32+TG This "new" value of T is then returned to the memory location in the EAROM 42 from which the old value was obtained and will subsequently be used during the initiation of the next game, as described above with reference to Fig. 4.

In addition to providing the capability of a selfadjusting difficulty feature that is generally immune to loss of power, the apparatus used to implement this feature (i.e., the NMI counter 64 and the EAROM 42) serves other functions. Thus, for example, the MPU 30 can determine the time that the machine has had power applied to it since a predetermined prior time, or the time the video game 10 has actually been played since such predetermined prior time, and these quantities are periodically updated and stored in the EAROM 42, where they remain involatile from power interruptions. Such information is useful to an operator by providing him with an indication of consumer appeal of the game. Additionally, a number of the highest scores attained on the video game 10 can also be stored in the EAROM 42 and periodically checked by the MPU 30 with each score attained after each game played. This information would give the operator/owner information respecting the option selection, to optimize game usage.

It should be evident to one skilled in this art that various changes and modifications may readily be made within the invention. For example, rather than basing game play skill upon the time that the video game 10 is played, the score attained each game can also be used. In addition, the method can be used to detect particularly incompetent players and return any money paid by the player. Further, a specific memory element, EAROM 42, has been used as the electrically non-volatile memory element.

However, it should be evident to those skilled in the art to which this invention pertains the other forms of electrically alterable non-volatile memory elements can be used. For example, magnetic bubble memories, ferrite core memories, thin-film memories, and even semiconductor memories with auxiliary battery backup, to name a few equivalent non-volatile devices, can be used.

It should be evident that such changes and modifications are within the scope and teachings of this invention as defined by the claims appended hereto.

Claims (14)

Claims

1. In an electronically controlled game apparatus to be operated by a player to effect a number of individual, sequential game-play operations thereof, the game apparatus being of the type operable in response to at least one of a number of operation parameters that establish, at least in part, the difficulty with which each gameplay operation is effected, a method of selfadjustment of difficulty of game-play operation, comprising the steps of: providing a first value indicative of a standard level of difficulty of game-play operation; determining, at the end of each game-play operation, a second value indicative of the skill with which the apparatus was operated; determining a one of said number of operation parameters in response to the first and second values for use by the game apparatus to effect future game-play operation.

2. The method of claim 1, wherein the game apparatus includes means for storing the second value, the second value corresponding to an average time of successive game-play operations; the determining step including the additional steps of producing a time value indicative of a time the game apparatus was operated by said player; accessing the second value from the storing means; combining the accessed second value with the time value to produce therefrom an updated second value and returning the updated second value to the storing means for storage; and wherein the one operating parameter is determined in response to the updated second value and the first value.

3. The method of claims 1 or 2, wherein the game apparatus includes a plurality of manipulative switches and memory means for storing a number of data words at preselected memory locations, each of the data words corresponding to a different first value; the providing step including the selection of a data word as the first value in response to the switch settings.

4. The method of claim 2, wherein the storing means comprises an electronically alterable nonvolatile memory means.

5. In a microprocessor controlled video game for providing individual player-initiated gameplays, the video game including means operable in response to an operating parameter, for establishing a difficulty of game-play, a method of self-adjustment of said game-play difficulty, the method comprising the initial steps of: providing a standard value indicative of a predetermined skill with which the video game is played; storing a skill value in response to the standard value; at the conclusion of each game-play and prior to each succeeding game-play:: (a) producing a first value indicative of the skill with which the concluding game-play was effected; (b) retrieving the stored skill value; (c) combining the first value with the retrieved skill value to produce therefrom an updated skill value indicative of the skill with which previous game-plays of the game apparatus were effected; (d) determining one of said operating parameters in response to the updated skill value and the standard value to establish a corresponding level of difficulty of game-play operation for said immediately succeeding game-play.

6. The method of claim 5, including the step of (e) replacing skill value with the updated skill value.

7. The method of claim 5 wherein the video game includes a display screen and means for displaying at least one computer controlled motion object on the display screen, and wherein the game parameter defines, at least in part, the speed of movement of the motion object on the display screen.

8. The method of claim 5, including the step of determining the time of each game-play, and wherein the producing step includes forming the first value from the time of concluding game-play.

9. In game apparatus of the type including a microprocessor, operable in response to a game program, for controlling game-play operation of the apparatus and a memory element coupled to the microprocessor for storing (1) the game program, (2) a plurality data words, each corresponding to a different level of game-play difficulty, a method of self-adjusting the difficulty of game-play of the game apparatus, comprising the steps of: selecting a one of said data words; determining a skill level value from actual game-play operation; determining a game-play operating parameter in response to the selected data words and the skill level value; and modifying game-play of subsequent games in response to the calculated game play operating parameter.

10. The method of claim 9, wherein the selecting step is preceded by the step of providing a manually operable means for allowing operator selection of the data words.

11. The method of claim 10, wherein the manually operable means includes a plurality of two-position switches.

12. The method of claim 11, wherein said switches are coupled to and readable by the microprocessor.

13. In a video game, including a microprocessor for controlling game-play operations in response to a stored program and a stored game parameter and memory means having a plurality of memory locations for storing the game program and the game parameter, apparatus for self-adjustment of game-play difficulty, comprising: means for monitoring each game-play operation to determine therefrom a game-play value indicative of the skill with which the video game is played; means for providing a standard value indicative of a predetermined skill; means responsive to the monitoring means and the providing means for redetermining the game parameter in response to the game-play and standard values.

14. The apparatus of claim 13, wherein the monitoring means includes clock means for producing a time signal during each game-play operation; and counting means responsive to the time signal to provide the game-play value in response to the time of game-play operation.

1 5. The apparatus of claim 13, wherein the memory means includes a plurality of additional memory locations containing a number of different ones of the standard value and the providing means includes a number of manually operable switches for allowing an operator to select a one of the different ones of the standard value.

1 6. In an electronically-controlled video game of the type operable in response to electrical power and including control elements operable by a player during game-play operation to produce data input signals indicative of player contribution to the game-play operation, a microprocessor for effecting and controlling game-play operation in response to the data input signals and a stored program, and memory means operatively coupled to the microprocessor for storing the program; the improvement comprising: means for providing a characteristic value indicative of game-play operation by the player; means for calculating a characteristic cumulative value in response to a plurality of game-plays; and an electronically-alterable read-only-memory element coupled to the microprocessor for storing the characteristic cumulative values, the electronically-alterable read-only-memory being operably accessible to the microprocessor for both read and write operations for storing and retrieving the player-generated values by the microprocessor, the electronically-alterable readonly-memory being further operable to retain the stored plurality of player-generated values when the electric power is removed from the video game.

1 7. A game as in claim 1 6 wherein the gameplay operation is responsive to the characteristic cumulative value.

1 8. A method of self-adjusting the difficulty of a video game substantially as hereinbefore described with reference to and as illustrated in the accompanying drawings.

1 9. Video game apparatus substantially as hereinbefore described with reference to and as illustrated in the accompanying drawings.