A gaming machine and method for providing a feature game

Abstract

10 20 26 20 47 04 17 J un 2 02 6 A B S T R A C T 2 0 2 6 2 0 4 7 0 4 1 7 J u n 2 0 2 6 5 1 0

Description

RELATED APPLICATION 5 This application is a divisional application of Australian Patent Application No. 2024278385, which in turn is a divisional application of Australian application no. 2023202888, which in turn is a divisional application of Australian application no. 2021201699, which in turn is a divisional application of Australian application no. 2018278882, which in turn is a divisional of 10 Australian application no. 2017200840, which in turn is a divisional application of Australian application no. 2015210489. The disclosure of each of these applications is incorporated herein by reference. FIELD OF THE INVENTION 15 The present invention relates to a gaming machine and a method of gaming. BACKGROUND OF THE INVENTION In existing gaming machines, feature games may be triggered for players in addition to the base game. A feature game gives players an additional opportunity to win prizes, or the 20 opportunity to win larger prizes, than would otherwise be available in the base game. Feature games can also offer altered game play to enhance player enjoyment. A need exists for new gaming machines that have components that enable them to provide alternative feature games. 25 SUMMARY OF THE INVENTION According to one aspect of the invention, there is provided a gaming machine comprising: a credit input mechanism configured to receive a physical item representing a monetary value for establishing a credit balance, the credit balance being increasable and 30 decreasable based at least on wagering activity; a credit meter configured to monitor the credit balance; a manually operable player interface configured to, in accord with the wagering activity, initiate play of a base game; an electronic display having a display area, said display area having a plurality of 35 display positions; 2026204704   17 Jun 2026 a memory storing data indicative of a set of symbols including a plurality of symbols having a particular characteristic; an evaluator configured to monitor the occurrence of a trigger event, and to trigger a feature game in response to the occurrence of a trigger event, said feature game comprising a 5 variable number of free games; a free game counter configured to generate a count representing a number of free games remaining to be played; and wherein said evaluator is configured to revise said free game counter upon the occurrence of a defined outcome of a free game and to end the feature game when said count 10 reaches a predetermined end count; wherein, during the feature game, the symbol selector is configured for each free game to: 1) hold at least some of the displayed symbols having the particular characteristic appearing on the display; 15            2) remove at least one of the displayed symbols without the particular characteristic from the display; 3) select randomly a replacement symbol from the set of symbols to replace a removed symbol without the particular characteristic; and 4) replace the removed said one of the displayed symbols without the particular 20 characteristic with the selected replacement symbol, and wherein the outcome evaluator is configured to make an award upon a matrix of display positions being filled by symbols having the particular characteristic. In an embodiment, the symbol selector selects each replacement symbol from an individual 25 reel associated with an individual symbol position. In an embodiment, the award is a highest jackpot prize. In an embodiment, the award is a Grand Jackpot. 30 In an embodiment, the outcome evaluator is configured to revise the count of the free game counter based on the selected replacement symbol in the outcome of a free game having said particular characteristic and including resetting the count of the free game counter 2026204704   17 Jun 2026 In an embodiment, the free game counter maintains the count of free games to be awarded in the feature game, and wherein a predefined number of free games is initially awarded when the feature game is triggered. 5 In an embodiment, said outcome evaluator is configured to reset the count of the free game counter based on said another symbol having said particular characteristic. In an embodiment, said counter is reset to a predefined number of free games. 10 In an embodiment, the free game counter is decremented each time the outcome of a free game does not have said another symbol with said particular characteristic. BRIEF DESCRIPTION OF THE DRAWINGS OF THE INVENTION Features and advantages of certain embodiments of the present invention will become 15 apparent from the following description of embodiments thereof, by way of example only, with reference to the accompanying drawings, in which: Figure 1 is a block diagram of the core components of a gaming machine; 20 Figure 2 is a perspective view of a standalone gaming machine; Figure 3 is a block diagram of the functional components of a gaming machine; Figure 4 is a schematic diagram of the functional components of a memory; 25 Figure 5 is a schematic diagram of a network gaming system; Figure 6 is a further block diagram of a gaming machine; 30 Figure 7 is a flow diagram of a feature game of the gaming machine of Figure 2; Figure 8 is a representation of a screen of the feature game of Figure 7; Figures 9A-9C are screen shots of the feature game of Figure 7; 35 2026204704   17 Jun 2026 Figures 10A and 10B are screen shots of the feature game of Figure 7, showing one of the progressive jackpot prizes being won; Figure 11 is a flow diagram of a free games feature of the gaming machine; and 5 Figures 12A and 12 B are screen shots of the free games feature. The foregoing summary, as well as the following detailed description of certain embodiments of the present invention, will be better understood when read in conjunction with the 10 appended drawings. For the purpose of illustrating the invention, certain embodiments are shown in the drawings. It should be understood, however, that the present invention is not limited to the arrangements and instrumentality shown in the attached drawings. DETAILED DESCRIPTION OF A PREFERRED EMBODIMENT OF THE INVENTION 15 Referring to the drawings, there are shown example embodiments of gaming machines having components which enable the implementation a base game, from which may be triggered a series of free games or a spin and hold feature game. In these embodiments, during the free games, symbols are selected from a set of symbols comprising a plurality of configurable symbols, non-configurable symbols and reveal symbols. If reveal symbols are selected for 20 display, a replacement symbol is selected to replace the reveal symbol. The replacement symbol may be a configurable symbol. In one example, the gaming machine is configured so that the hold and spin feature game is triggered when six of the configurable symbols are selected for display. The invention is not limited to a gaming machine which is configured to trigger a feature game only when six configurable symbols are selected, however. In other 25 embodiments, a different number of configurable symbols may trigger the feature game. Furthermore, each of the configurable symbols comprises a variable portion which is indicative of the value of a prize. The gaming machine comprises a value assigner which enables it to assign values to the variable portions. When the feature game is triggered, the 30 player is guaranteed to win the accumulated value of the prizes indicated by the variable portions of the configurable symbols. General construction of gaming machine 35 The gaming machine can take a number of different forms. In a first form, a standalone gaming machine is provided wherein all or most components required for implementing the game are present in a player operable gaming machine. 2026204704   17 Jun 2026 In a second form, a distributed architecture is provided wherein some of the components required for implementing the game are present in a player operable gaming machine and some of the components required for implementing the game are located remotely relative to 5 the gaming machine. For example, a “thick client” architecture may be used wherein part of the game is executed on a player operable gaming machine and part of the game is executed remotely, such as by a gaming server; or a “thin client” architecture may be used wherein most of the game is executed remotely such as by a gaming server and a player operable gaming machine is used only to display audible and / or visible gaming information to the 10 player and receive gaming inputs from the player. However, it will be understood that other arrangements are envisaged. For example, an architecture may be provided wherein a gaming machine is networked to a gaming server and the respective functions of the gaming machine and the gaming server are selectively 15 modifiable. For example, the gaming machine may operate in standalone gaming machine mode, “thick client” mode or “thin client” mode depending on the game being played, operating conditions, and so on. Other variations will be apparent to persons skilled in the art. Irrespective of the form, the gaming machine 1 has several core components. At the broadest 20 level, the core components are a player interface 50 and a game controller 60 as illustrated in Figure 1. The player interface is arranged to enable manual interaction between a player and the gaming machine and for this purpose includes the input / output components required for the player to enter instructions to play the game and observe the game outcomes. 25 Components of the player interface may vary from embodiment to embodiment but will typically include a credit mechanism 52 to enable a player to input credits and receive payouts, one or more displays 54, a game play mechanism 56 including one or more input devices that enable a player to input game play instructions (e.g. to place a wager), and one or more speakers 58. 30 The game controller 60 is in data communication with the player interface and typically includes a processor 62 that processes the game play instructions in accordance with game play rules and outputs game play outcomes to the display. Typically, the game play rules are stored as program code in a memory 64 but can also be hardwired. Herein the term 35 “processor” is used to refer generically to any device that can process game play instructions in accordance with game play rules and may include: a microprocessor, microcontroller, programmable logic device or other computational device, a general purpose computer (e.g. a 2026204704   17 Jun 2026 PC) or a server. That is a processor may be provided by any suitable logic circuitry for receiving inputs, processing them in accordance with instructions stored in memory and generating outputs (for example on the display). Such processors are sometimes also referred to as central processing units (CPUs). Most processors are general purpose units, however, it 5 is also known to provide a specific purpose processor using an application specific integrated circuit (ASIC) or a field programmable gate array (FPGA). A gaming machine in the form of a standalone gaming machine 10 is illustrated in Figure 2. The gaming machine 10 includes a console 12 having a display 14 on which are displayed 10 representations of a game 16 that can be played by a player. A mid-trim 20 of the gaming machine 10 houses a bank of buttons 22 for enabling a player to interact with the gaming machine, in particular during game play. The mid-trim 20 also houses a credit input mechanism 24 which in this example includes a coin input chute 24A and a bill collector 24B. Other credit input mechanisms may also be employed, for example, a card reader for reading 15 a smart card, debit card or credit card. Other gaming machines may configure for ticket in such that they have a ticket reader for reading tickets having a value and crediting the player based on the face value of the ticker. A player marketing module (not shown) having a reading device may also be provided for the purpose of reading a player tracking device, for example as part of a loyalty program. The player tracking device may be in the form of a card, 20 flash drive or any other portable storage medium capable of being read by the reading device. In some embodiments, the player marketing module may provide an additional credit mechanism, either by transferring credits to the gaming machine from credits stored on the player tracking device or by transferring credits from a player account in data communication with the player marketing module. 25 A top box 26 may carry artwork 28, including for example pay tables and details of bonus awards and other information or images relating to the game. Further artwork and / or information may be provided on a front panel 29 of the console 12. A coin tray 30 is mounted beneath the front panel 29 for dispensing cash payouts from the gaming machine 10. 30 The display 14 shown in Figure 2 is in the form of a video display unit, particularly a liquid crystal display. Alternatively, the display 14 may be a OLED, plasma screen, any other suitable video display unit. The top box 26 may also include a display, for example a video display unit, which may be of the same type as the display 14, or of a different type. 35 Figure 3 shows a block diagram of operative components of a typical gaming machine which may be the same as or different to the gaming machine of Figure 2. 2026204704   17 Jun 2026 The gaming machine 10 includes a game controller 101 having a processor 102 mounted on a circuit board. Instructions and data to control operation of the processor 102 are stored in a memory 103, which is in data communication with the processor 102. Typically, the gaming 5 machine 10 will include both volatile and non-volatile memory and more than one of each type of memory, with such memories being collectively represented by the memory 103. The gaming machine has hardware meters 104 for purposes including ensuring regulatory compliance and monitoring player credit, an input / output (I / O) interface 105 for 10 communicating with peripheral devices of the gaming machine 100. The input / output interface 105 and / or the peripheral devices may be intelligent devices with their own memory for storing associated instructions and data for use with the input / output interface or the peripheral devices. A random number generator module 113 generates random numbers for use by the processor 102. Persons skilled in the art will appreciate that the reference to 15 random numbers includes pseudo-random numbers. In the example shown in Figure 3, a player interface 120 includes peripheral devices that communicate with the game controller 101 including one or more displays 106, a touch screen and / or buttons 107 (which provide a game play mechanism), a card and / or ticket reader 108, 20 a printer 109, a bill acceptor and / or coin input mechanism 110 and a coin output mechanism 111. Additional hardware may be included as part of the gaming machine 100, or hardware may be omitted as required for the specific implementation. For example, while buttons or touch screens are typically used in gaming machines to allow a player to place a wager and initiate a play of a game any input device that enables the player to input game play 25 instructions may be used. For example, in some gaming machines a mechanical handle is used to initiate a play of the game. Persons skilled in the art will also appreciate that a touch screen can be used to emulate other input devices, for example, a touch screen can display virtual buttons which a player can “press” by touching the screen where they are displayed. 30 In addition, the gaming machine 100 may include a communications interface, for example a network card 112. The network card may, for example, send status information, accounting information or other information to a bonus controller, central controller, server or database and receive data or commands from the bonus controller, central controller, server or database. In embodiments employing a player marketing module, communications over a 35 network may be via player marketing module - i.e. the player marketing module may be in data communication with one or more of the above devices and communicate with it on behalf of the gaming machine. 2026204704   17 Jun 2026 Figure 4 shows a block diagram of the main components of an exemplary memory 103. The memory 103 includes RAM 103A, EPROM 103B and a mass storage device 103C. The RAM 103A typically temporarily holds program files for execution by the processor 102 and related 5 data. The EPROM 103B may be a boot ROM device and / or may contain some system or game related code. The mass storage device 103C is typically used to store game programs, the integrity of which may be verified and / or authenticated by the processor 102 using protected code from the EPROM 103B or elsewhere. It is also possible for the operative components of the gaming machine 100 to be distributed, 10 for example input / output devices 106,107,108,109,110,111 to be provided remotely from the game controller 101. Figure 5 shows a gaming system 200 in accordance with an alternative embodiment. The gaming system 200 includes a network 201, which for example may be an Ethernet network. 15 Gaming machines 202, shown arranged in three banks 203 of two gaming machines 202 in Figure 5 are connected to the network 201. The gaming machines 202 provide a player operable interface and may be the same as the gaming machines 10,100 shown in Figures 2 and 3, or may have simplified functionality depending on the requirements for implementing game play. While banks 203 of two gaming machines are illustrated in Figure 5, banks of one, 20 three or more gaming machines are also envisaged. One or more displays 204 may also be connected to the network 201. For example, the displays 204 may be associated with one or more banks 203 of gaming machines. The displays 204 may be used to display representations associated with game play on the gaming 25 machines 202, and / or used to display other representations, for example promotional or informational material. In a thick client embodiment, game server 205 implements part of the game played by a player using a gaming machine 202 and the gaming machine 202 implements part of the 30 game. With this embodiment, as both the game server and the gaming device implement part of the game, they collectively provide a game controller. A database management server 206 may manage storage of game programs and associated data for downloading or access by the gaming devices 202 in a database 206A. Typically, if the gaming system enables players to participate in a Jackpot game, a Jackpot server 207 will be provided to perform accounting 35 functions for the Jackpot game. A loyalty program server 212 may also be provided. 2026204704   17 Jun 2026 In a thin client embodiment, game server 205 implements most or all of the game played by a player using a gaming machine 202 and the gaming machine 202 essentially provides only the player interface. With this embodiment, the game server 205 provides the game controller. The gaming machine will receive player instructions, pass these to the game server which will 5 process them and return game play outcomes to the gaming machine for display. In a thin client embodiment, the gaming machines could be computer terminals, e.g. PCs running software that provides a player interface operable using standard computer input and output components. Other client / server configurations are possible, and further details of a client / server architecture can be found in WO 2006 / 052213 and PCT / SE2006 / 000559, the 10 disclosures of which are incorporated herein by reference. Servers are also typically provided to assist in the administration of the gaming network 200, including for example a gaming floor management server 208, and a licensing server 209 to monitor the use of licenses relating to particular games. An administrator terminal 210 is 15 provided to allow an administrator to run the network 201 and the devices connected to the network. The gaming system 200 may communicate with other gaming systems, other local networks, for example a corporate network, and / or a wide area network such as the Internet, for 20 example through a firewall 211. Persons skilled in the art will appreciate that in accordance with known techniques, functionality at the server side of the network may be distributed over a plurality of different computers. For example, elements may be run as a single “engine” on one server or a 25 separate server may be provided. For example, the game server 205 could run a random generator engine. Alternatively, a separate random number generator server could be provided. Further, persons skilled in the art will appreciate that a plurality of game servers could be provided to run different games or a single game server may run a plurality of different games as required by the terminals. 30 Further detail of gaming machine The player operates the game play mechanism 56 to specify a wager and hence the win entitlement which will be evaluated for this play of the base game part of the game and 35 initiates a play of the game. Persons skilled in the art will appreciate that a player’s win entitlement will vary from game to game dependent on player selections. In most spinning reel games, it is typical for the player’s entitlement to be affected by the amount they wager 2026204704   17 Jun 2026 and selections they make (i.e. the nature of the wager). For example, a player’s win entitlement may be based on how many lines they play in each game - e.g. a minimum of one line up to the maximum number of lines allowed by the game (noting that not all permutations of win lines may be available for selection) and how much they wager per line. 5 Such win lines are typically formed by a combination of symbol display positions, one from each reel, the symbol display positions being located relative to one another such that they form a line. In many games, the player’s win entitlement is not strictly limited to the lines they have 10 selected, for example, “scatter” pays are awarded independently of a player’s selection of paylines and are an inherent part of the win entitlement. Persons skilled in the art will appreciate that in other embodiments, the player may obtain a win entitlement by selecting a number of reels to play and an amount to wager per reel. Such 15 games are marketed under the trade name “Reel Power” by Aristocrat Leisure Industries Pty Ltd. The selection of the reel means that each displayed symbol of the reel can be substituted for a symbol at one or more designated display positions. In other words, all symbols displayed at symbol display positions corresponding to a selected reel can be used to form symbol combinations with symbols displayed at a designated, symbol display positions of the 20 other reels. For example, if there are five reels and three symbol display positions for each reel such that the symbol display positions comprise three rows of five symbol display positions, the symbols displayed in the centre row are used for non-selected reels. As a result, the total number of ways to win is determined by multiplying the number of active display positions of each reel, the active display positions being all display positions of each selected 25 reel and the designated display position of the non-selected reels. As a result for five reels and fifteen display positions there are 243 ways to win. In Figure 6, the processor 62 of game controller 60 of gaming machine 1 is shown implementing a number of modules based on game program code 641 stored in memory 64. 30 Persons skilled in the art will appreciate that various of the modules could be implemented in some other way, for example by a dedicated circuit. These modules include the outcome generator 622 which operates in response to the player’s operation of game play mechanism 56 to place a wager and initiate a play of the game and 35 generates a game outcome which will then be evaluated by outcome evaluator 623. The first part of forming the game outcome is for a symbol selector 622A to select symbols from a set of symbols specified by symbol data 642 using random number generator 621. The selected 2026204704   17 Jun 2026 symbols are advised to the display controller 625 which causes them to be displayed as a symbol display on display 54 at a set of display positions. In the embodiment described below, the display positions of the symbol display are arranged 5 in a rectangular matrix comprising a plurality of columns and a plurality of rows. However, in other arrangements as known in the gaming industry could be employed in embodiments of the invention. For example, in some arrangements there are more symbols in some columns than other, such as 3-4-3-4-3 arrangement of seventeen display positions corresponding to respective ones of five reels. In such arrangements, the columns of four symbols can be 10 arranged so that they are off-set or staggered relative to the columns having two symbols so that the middle two symbols in the columns of four symbols share boundaries with two symbols of each neighbouring reel. Figure 7 shows a flow diagram of one embodiment, in which a feature game may be triggered 15 from play of the base game at step 702. In this embodiment, the base game comprises using symbol selector 622A to select a plurality of symbols from a set of symbols to display at the respective display positions arranged on display 54, at step 704. The set of symbols, which are stored as symbol data 642 in memory 64, comprises a plurality of configurable symbols and non-configurable symbols and the gaming machine has a value assigner that enables it to 20 assign values to the configurable symbols. In an embodiment, the configurable symbols each comprise at least a common component and at least a variable component assigned by the value assinger. The variable component is indicative of a value of a prize that is associated with each of the configurable symbols. An 25 example of a configurable symbol is shown in Figures 9A-9C, in the form of a pearl symbol. The common component is the pearl itself 902, while the variable component is the indicia 904 overlaying pearl 902. In this case, indicia 902 are numerals directly indicative of the value of the prize. In other embodiments, such as shown in Figure 10A-10B, the indicia indirectly indicate the value of the prize, such as “major” indicia 1002, “minor” indicia 1004 or “mini” 30 indicia 1006. It will be appreciated that the indicia can also be in other forms, which may also be indicative of a prize. For example, the car icon indicates that the player has the opportunity to, or has, won a car. In some embodiments, the indicia may indicate only a portion of a prize. Continuing with the car example, the car icon may be split into four portions, each portion being assigned to a different configurable symbol. In such 35 embodiments, all four portions of the car icon are required to be selected for display in order for the car prize to be won. 2026204704   17 Jun 2026 In one embodiment, at least one value of the respective prizes is generated by the value assigner 622C randomly selecting one of a plurality of defined multipliers that is applied to an amount wagered on the base game from which the feature is game triggered. This is accomplished at step 706 by value assigner 622C selecting the defined multipliers from value 5 data 644 using a value obtained from the random number generator (RNG) 621. The value assigner 622C then applies the multiplier to the initial wager to obtain a prize value and assigns the prize value to each of the configurable symbols selected by symbol selector 622A. In this embodiment, the plurality of defined multipliers are selected at random according to a weighted probability based at least in part on the amount wagered on the base game. That 10 is, for at least each configurable symbol which will be displayed, the value assigner 622C obtains a value from RNG 621 and uses this to determine from the weighted table which value to assign. In an embodiment, the assignment of values to the configurable symbols is performed by the value assigner 622C after the symbols have been selected and the game controller knows they will be displayed but before they are displayed on the display. In 15 another embodiment, the assignment occurs after the symbols have been displayed on display 54. In an embodiment, values are assigned by the value assigner 622C to all configurable symbols irrespective of whether they will be displayed. In this or other embodiments, at least one value of the respective prizes assigned by the value 20 assigner may comprise a defined value and / or a jackpot. As used herein, the term “jackpot”, as opposed to “prize”, refers to a progressive prize which accumulates over multiple plays of the base game and / or the feature game. As will be appreciated, the jackpot may be funded from a variety of sources including from only the gaming machine 10 itself, or from a plurality of gaming machines 202 - a so-called “link”. Furthermore, the jackpot may be triggered by 25 any means known in the art, such as by using a mystery trigger or by using the Hyperlink™ system developed by the applicant. In another embodiment, the variable prizes may be randomly selected under the control of value assigner 622C from a set of available prizes. Specific prizes may be weighted so as to 30 control the probability of certain prizes occurring. In some embodiments, there may be a plurality of sets of prizes and the value assigner 622C may be configured to choose the set of prizes from which values will be randomly selected on the basis of a player’s wager in the base game. 35 Returning to Figure 7, at step 710, outcome evaluator 623 monitors play of the base game and determines whether a trigger event has occurred. In this embodiment, a trigger event occurs when six configurable symbols appear on display 54. If a trigger event has not occurred, play 2026204704   17 Jun 2026 of the base game continues and control reverts to step 702, once any awards are paid at step 708. However, if a trigger event does occur, the feature game initiates by first holding the configurable symbols in their respective display positions 824, at step 711. Outcome generator 622 causes the feature game to be displayed on display 54 by retrieving symbol 5 data 642 from memory 64 and passing the data to display controller 625 which controls display 54 to display the feature game. In other embodiments, more than or less than six symbols will be required to trigger the feature game, or the feature game will be modified in a way that is proportional to the number of configurable symbols that are displayed to trigger the feature game. For example, the average or total prize achievable in the feature game may 10 be increased in proportion to the number of configurable symbols appearing. When the feature game starts, the configurable symbol counter 810 of Figure 8 is, in this embodiment, set to the number of configurable symbols that are held on reels 814-822 at step 712. In the preferred embodiment, this is also the number of configurable symbols which 15 originally triggered the feature game. That is, in this embodiment, the configurable symbol counter 810 is initially set to 6, as six configurable symbols are required to trigger the feature game. Once configurable symbol counter 810 is set, control moves to step 714 which sets feature 20 game counter 812 to the defined number of feature games. In an embodiment, the preferred number of feature games is three, so counter 812 is set to 3. In other embodiments, the number of feature games may be more than or less than three, or may be derived by the game controller from the number of configurable symbols that appear. For example, an additional feature game may be offered for each configurable symbol that appears in addition 25 to a defined minimum required to trigger the feature game. Then, similar to the base game, the symbol selector 622A selects symbols from symbol data 642 to be displayed in the other display positions 824 not already displaying a configurable symbol, via display controller 625 at step 716. Note that in this embodiment, symbols in the 30 feature game are selected from the full set of symbols defined by symbol data 642, including any configurable symbols. In other embodiments, the symbols may be selected from a reduced set of symbols taking into account of the configurable symbols already held. In an alternative embodiment, the symbols may be selected from an increased set of symbols. For example, symbols may be purchased or otherwise awarded for addition to the reel strip prior 35 to the initiating the feature game. If one or more configurable symbols are selected, value assigner 622C assigns randomly selected values to each configurable symbol . 2026204704   17 Jun 2026 Outcome evaluator 623 then monitors play of the feature game to determine whether a configurable symbol is selected and displayed at step 718. If a configurable symbol is not displayed, feature game counter 812 is decremented by a defined amount at step 720. In the preferred embodiment, feature game counter 812 is only decremented by one, but of course 5 the counter may be decremented by any number as is known in the art. If there are a number of feature games remaining as determined by controller 60 at step 722, control returns to step 716 to continue the feature game. On the other hand, once the number of feature games is depleted, that is, when the feature game counter 812 reaches 10 zero, an end condition is met, the feature game ends and control returns to step 702 after any prizes are paid at step 728. In one embodiment, the accumulated value of all the individual prizes as indicated by the variable components of the collected configurable symbol is paid at step 728. 15 Returning to step 718, if outcome evaluator 623 determines that at least one configurable symbol is displayed on reels 814-822, then that symbol is held on the reel and the configurable symbol counter 810 is incremented at step 724. Outcome evaluator 623 then checks whether a defined number of configurable symbols has been displayed on reels 814822 at step 726 and, if the defined number has been reached, a jackpot is paid at step 728. 20 The defined number of configurable symbols required to trigger a jackpot in this embodiment is fifteen. That is, for this embodiment in which a game is implemented using a 5x3 matrix, configurable symbols must be selected and displayed in all the matrix positions of reels 814822. In other embodiments, the defined number may be more than or less than fifteen. For 25 example, in a 3-4-3-4-3 matrix configuration discussed as discussed above, the number of configurable symbols required to fill all matrix positions would be 17. In yet other embodiments, not all of the matrix positions need necessarily be filled, and the number of configurable symbols required may be determined randomly. 30 While in the above embodiments, an end condition is that the feature game ends when the Grand jackpot 802 is triggered at step 726, in other embodiments, the feature game does not necessarily end at this point. In such embodiments, one or more of reels 814-822 are configured to expand and display additional configurable or non-configurable symbols when counter 810 reaches the defined number. For example, a game implemented using a 5x3 35 matrix may expand to a 3-4-3-4-3 configuration. In such embodiments, a prize in addition to the Grand jackpot 802 is paid if configurable symbols are also selected for display in those additional positions. 2026204704   17 Jun 2026 Alternatively, if outcome evaluator 623 determines that the defined number of configurable symbols has not been reached at step 726, the feature game continues. In the embodiment of Figure 7, each time a configurable symbol is displayed and the jackpot is not won, feature 5 game counter 812 is reset to the default position by returning control to step 714, which in this embodiment is three as noted above. Therefore, the number of feature games awarded by the outcome evaluator 623 is indefinite and is not determined by a defined limit. In this or other embodiments, if no configurable symbols appear on reels 814-822 in any of 10 the feature games initially awarded, feature games counter 812 is reset. Such embodiments ensure the player is guaranteed to win a prize over and above the prize payable for triggering the feature game. In the above embodiments, the jackpot paid in response to counter 810 reaching the defined 15 threshold is the Grand prize 802. The grand prize in this embodiment is a linked jackpot which receives contributions from a plurality of linked gaming machines and is incremented based on the turnover of the linked machines. In some embodiments, a lower threshold of configurable symbols may be required for Major prize 804, Minor prize 806 or Mini prize 808 to be won. Alternatively or additionally, as best shown in Figures 10A and 10B, Major, Minor 20 and Mini prizes may be paid by assignment of those prizes to one of the configurable symbols, such as “major” indicia 1002, “minor” indicia 1004 or “mini” indicia 1006. Note that in some embodiments, one or all of the Grand 802, Major 804, Minor 806 and Mini 808 prizes may all be implemented as jackpots, as fixed bonus amounts that do not increment 25 or as a mixture of both. In the embodiment of Figures 9A to 10B, as noted above, Grand prize 802 is implemented as a linked progressive jackpot, while Major prize 804 is implemented as a standalone progressive (SAP) jackpot which only takes contributions from the gaming machine itself, incrementing the jackpot as a function of turnover. Minor 806 and Mini 808 prizes are implemented as fixed bonus amounts in proportion to the initial bet wagered. In some 30 embodiments, Grand 802 prize may also be implemented as a SAP, or the Major 804 prize may also be implemented as a link. This embodiment implements Grand 802 and Major 804 prizes as jackpots and, while both may be awarded simultaneously, neither can be awarded more than once in the same feature 35 game. However, in other embodiments, either jackpot may be won multiple times within the same feature game. In such embodiments, players are awarded a seed value of the jackpot for subsequent triggers of that same jackpot. 2026204704   17 Jun 2026 As embodiments of the feature game described above automatically adjust awards based on turnover and proportionality to the initial wager, this invention is particularly suited to variable denomination games. Therefore, in some embodiments, controller 60 allows player 5 selection of the minimum bet denomination. For example, before play of the game, controller 60 causes display controller 625 to output a message on display 54 requesting the player to select a minimum bet denomination. The player makes a selection through the game play mechanism 56 in response to which controller 60 adjusts the amount contributed to Grand 802 and Major 804 jackpot prizes and the magnitude of Minor 806 and Mini 808 bonus 10 awards. Controller 60 also adjusts the weightings of the values in value data 644 from which value assigner 622C may assign to the configurable symbols. In one embodiment, there are four denominations available for selection, 1c, 2c, 5c and 10c. Those skilled in the art would appreciate that the denominations are not limited to four, but can include any suitable amount in any given currency. Note also that in this embodiment, while the selected 15 denomination affects the magnitude of the Minor 806 and Mini 808 fixed bonus prizes offered, it does not affect the magnitude of the Grand 802 and Major 804 jackpots - only the contributions funding the amount. Referring again to Figure 7, it will be apparent that the flow chart includes a free games 20 process at step 707. Like the spin and hold feature game , the free games series is an event which occurs only periodically if a trigger condition is met and not during every play of the game as is the case with a base game. The free game process 707 is detailed in Figure 11. In an embodiment, the free game process 25 involves the step 1105 of determining whether free games are triggered. In an embodiment, the trigger is a defined number of a defined symbol being selected for display by the symbol selector. For example, three or more scatter symbols appearing anywhere in the display positions. If the free games are not triggered, the process continues to step 710. 30 If free games are triggered, at step 1110 a free game counter is set to a defined number of free games. For example, eight free games. The free games process 707 then involves selecting symbols from a free games symbol set 1115. In one example, the free game symbol set comprises a set of reels formed from the set 35 of symbols used in the base game and a plurality of reveal symbols. The free game symbol set is stored in symbol data 642 together with the set of symbols to be used during the base and feature game. 2026204704   17 Jun 2026 It will be appreciated that in other embodiments, the symbols of the free games set of symbols could be more significantly different to the symbols of the base games symbols. For example, the reveal symbol could replace a symbol used in the base game. It will be 5 appreciated that the free games symbol set includes a mixture of configurable and non-configurable symbols in a similar manner to the base game symbol set. After the symbols have been selected, the free games counter is decremented by one at step 1120. At step 1125, the method involves determining whether the selected symbols include configurable symbols, and if so, the value assigner assigns the values to each configurable symbol at step 10    1130. Again, any of the options for the value assigner to assign values to each configurable symbol described above can be used. In an embodiment, the method is the same as that used in the base game and the feature game. As indicated above, the set of free game symbols includes a plurality of reveal symbols. A 15 determination is made at step 1135 whether the selected symbols include one or more reveal symbols. If so, a process to select a replacement symbol from a set of replacement symbols is initiated at step 1140. In an example, the replacement symbol set comprises the full set of free game symbols minus the defined symbol for the trigger condition so that the selection of a replacement symbol for the reveal symbol can’t lead to a retrigger. In other embodiments, 20 the replacement symbol could be a reduced set of symbols for example symbols that are in higher value winning combinations defined in a pay table. Accordingly, in the embodiment, the set of replacement symbols which includes at least one configurable symbol. Accordingly, one possible result of selection of the replacement symbol is for the configurable symbol to be selected. Irrespective of what symbol is selected, this symbol will replace all of the reveal 25 symbols. Thus, the reveal symbol is termed a reveal symbol because it will reveal the replacement symbol. In an embodiment, at least one weighted table is used to control the selection of the replacement symbol. In an example, two weighted tables are used. A first table being used provided at least one display position is not occupied by a reveal symbol, and a second table being used if all one display positions are occupied by a reveal symbol. The 30 second table is configured to change on per bet basis to ensure the chance of a configurable symbol being revealed is proportional to the total credits bet, thereby making the probability of winning the Grand Jackpot linear. It will be apparent why the gaming machine is configured to operate in this manner from the following description. 35 At step 1145, it is determined whether the replacement symbol is a configurable symbol. If the replacement symbol is a configurable symbol, step 1150 the method involves at assigning a value to each configurable symbol. That is, even though a configurable symbol is chosen to 2026204704   17 Jun 2026 replace each reveal symbol, the values assigned to the respective configuration symbols can be different. In this respect, referring to Figure 12 it will be apparent that there is shown an exemplary screenshot in Figure 12A where the sixth free game in a series of free games is being carried out as indicated in free games counter 1210. 5 It will be apparent that Figure 12A that a display shows the gaming machine after a set of symbols have been selected for the free game where two configurable symbols have been selected but before the replacement symbol selected for the reveal symbols has been displayed. The configurable symbols 1226, 1227 are in the form of coin symbols having text 10 thereon which show their configure values, in this example values of 1000 credits (configurable symbol 1226) and 250 credits (configurable symbol 1227). Five reveal symbols in the form of “Wanted Poster” symbols 1231 to 1235 have also been selected. Figure 12B shows the same free game after a replacement symbol has been selected. It will 15 be apparent that the replacement symbol that has been selected is a configurable symbol and values have been assigned to each of the configurable symbol by the value assigner 622C. Specifically, a major jackpot prize value that has been assigned to configurable symbol 1221, the value of 150 credits has been assigned to configurable symbol 1222, a prize of 250 credits has been assigned to configurable symbol 1223, a prize of a mini bonus has been assigned to 20 configurable symbol 1224, and a prize of a 50 credit value has been assigned to configurable symbol 1225. Returning now to Figure 11, it is determined at step 1160 whether the spin and hold feature game is triggered using the same trigger condition used in respect of the feature game 25 described above. If so, the free game process 707 continues to steps 711 with all of the configurable symbols held in the manner described above in relation to Figure 7. That is, the gaming machine operates such that the feature game described above is carried out as a result of the trigger condition being met within the feature game. 30 Otherwise, the process continues to awarding any prize and determining whether a retrigger is included within the set of symbols that were selected at step 1170. In an embodiment retrigger is achieved by the same number of defined symbols appearing at scatter positions as was required to initially trigger the feature game. In an embodiment, the retrigger can be allowed on only the first occasion where it occurs. In an example, eight further free games are 35 added to the counter at step 1175 if a retrigger occurs. 2026204704   17 Jun 2026 At step 1180, it is determined whether the free game counter equals “0” and if so, the method continues to step 710 of Figure 7 such that in the unlikely event of a set of symbols containing both the free game trigger and the feature trigger, both are carried out. In an alternate embodiment, if the selected symbols include both the free game trigger and the feature 5 trigger, only the feature trigger is carried out. If at step 1180, the free game counter is greater than zero the process continues to step 1115 and a further free game is carried out by selecting further symbols and carrying out the subsequent steps described above. 10 Referring to Figure 7, it will be apparent that the method also involves determining whether a feature was triggered from a free game 730 and if it was, returning to the free game process at step 732 which returns the gaming machine to the step of determining whether the free game counter has been decremented to “0” such that the gaming machine can play out the 15 remaining free games. For example, the two games left on the counter in the example of Figure 12. It will be apparent from the above description that an advantage of the free game process 707 described in Figure 11 is that the gaming machine is constructed so as to provide a second 20 opportunity for the player to trigger the feature game by means of the use of the reveal symbol within the free game process. As such, the gaming machine is constructed such that the free game series is integrated with the hold and spin feature game. Further, this is done so in a manner which ensures that once the feature game is triggered, the player has at least a guaranteed prize from the values of the configurable symbols. Accordingly, the embodiments 25 provide a significantly improved method of operating a gaming machine. Examples More specific examples of embodiments of the invention are now described with reference to 30 Figures 9A-10B. In general, as shown in these Figures, the game has a traditional 3 x 5 grid layout, and is referred to in the examples below as the “Hold & Spin” feature. Referring to Figure 9A, the Hold & Spin feature is triggered when six 6 pearl symbols 902 are selected for display. When triggered, pearls 902 are held in their respective display positions, 35 being all of column 1, column 2 rows 1 and 2 and column 5 row 1, and the controller 60 waits for a player instruction to initiate the game through game play mechanism 56. In some 2026204704   17 Jun 2026 embodiments, controller 60 will wait indefinitely while in other embodiments, controller 60 will wait for a defined period of time before automatically initiating the game. At this point, counter 810 is set to 6, and the player is guaranteed to win the accumulated 5 value as indicated by the variable components 904 of the six pearls 902. That is, even before play of Hold & Spin starts, the player has won 4,300 credits in the embodiment of Figure 9A. Moving on to Figure 9B, the player has spun an additional 4 pearls 902. Accordingly, counter 810 is incremented from 6 to 10 and feature games counter 812 is reset to default, which is 3 10 feature games in this embodiment. As compared to Figure 9A, the additional pearls 902 are selected for display at display positions C2R3, C3R1, C4R3 and C5R2, and are also held at those positions for the subsequent games. Over the remaining feature games, the player spins only an additional one pearl 902, 15 displayed at C4R1, as shown in Figure 9C. Accordingly the feature games end and the player wins the accumulated value of the values indicated on pearls 902. In this case, the total award is the 4,300 credits for the six pearls 902 that originally triggered the Hold & Spin game, plus the additional 5 pearls 902 selected during play of the Hold & Spin game - 5,800 credits. In this embodiment, the accumulated award is totalled at the end of the Hold & Spin game and 20 first transferred to the win meter 908 before being transferred to the credit meter 910 by the controller 60. Meter data 648 is adjusted accordingly before the next game can be initiated at step 702. In alternative embodiments, the accumulated award may bypass the win meter and be credited directly to the credit meter. 25 Figures 10A and 10B are examples showing the jackpots being own. In Figure 10A, value assigner 622C has assigned “Major” indicia 1002 to pearl 902, which has been selected for display at C4R1. This triggers Major prize 804 which, in one embodiment, is paid directly into credit meter 910 rather than first into win meter 908. That is, jackpot wins are paid immediately when they are won rather than being accumulated at the end of the Hold & Spin 30 game as per the other prizes described above. Thus in the Figure 10A embodiment, Major jackpot 804 is paid when the associated pearl 902 is selected, while the remaining 4,000 credits will be accumulated and paid at the completion of the feature game, in addition to any new pearls 902 that are selected and displayed in the remaining feature games. In alternative embodiments, the Major jackpot may be accumulated at the end of the feature game along 35 with the other 4,000 credits, and the accumulated total may be paid first into win meter 908 or directly into credit meter 910. 2026204704   17 Jun 2026 Figure 10B shows Grand jackpot 802 being triggered, as 15 pearls 902 have been selected for display in the matrix by the end of the feature game. Again, the Grand 802 jackpot is first accounted for and paid directly into credit meter 910, and the remaining prizes indicated by indicia 904 on pearls 902 are then accumulated and paid into win meter 908 before being 5 transferred to credit meter 910. Therefore, in this Figure 10B embodiment, the total winnings is made up of the initial Grand jackpot 802, plus 63,000 credits indicated by indicia 904 and Minor 806 and Mini 808 prizes indicated by “Minor” indicia 1004 and “Mini” indicia 1006. Again, in alternative embodiments, the Grand jackpot may be accumulated at the end of the feature game along with the other 63,000 credits, Minor prize 806 and Mini prize 808, and the 10 accumulated total may be paid first into win meter 908 or directly into credit meter 910. In another example, the configurable symbols may only be provided during part of the game, such as a feature game. 15 In another example, after a feature game is triggered, the game controller initiates a feature game using different reels to those used in the base game. In one example, in the feature game, individual reels are associated with each of the symbol display positions. That is, if there are fifteen symbol display positions, fifteen reels are available for use depending upon which of the display positions are occupied by the configurable symbols that caused the 20 feature game to trigger. Each of the reels comprises a mixture of non-configurable symbols and configurable symbols. In the first feature game, the symbol selector determines stopping positions for all of the reels not occupied by a configurable symbol. If any of the reels are stopped with a configurable symbol in place, that configurable symbol is held in position by holding / locking the reel (i.e. not spinning the reels in a subsequent feature game). That is, in 25 subsequent feature games, only the reels corresponding to symbol positions where a configurable symbol has not been displayed are re-spun. Each configurable symbol is assigned a value by value assigner 622C by randomly selecting a prize value from a set of prize values. The set of prize values from which values are selected depends on the player’s wager in the base game. As in the example, described above, a player is awarded the sum of the values of 30 the configurable symbols at the end of the feature games and may be awarded an additional prize such as a jackpot prize depending on what value the counter reaches during the feature games. In another example, the configurable symbol may have an alternative visual representation, 35 for example, a door which opens once the configurable symbol is displayed in a display position to reveal the assigned prize value. 2026204704   17 Jun 2026 As indicated above, the method may be embodied in program code. The program code could be supplied in a number of ways, for example on a tangible computer readable storage medium, such as a disc or a memory device, e.g. an EEPROM, (for example, that could replace part of memory 103) or as a data signal (for example, by transmitting it from a server). 5 Further, different parts of the program code can be executed by different devices, for example in a client server relationship. Persons skilled in the art, will appreciate that program code provides a series of instructions executable by the processor. It is to be understood that, if any prior art is referred to herein, such reference does not 10 constitute an admission that the prior art forms a part of the common general knowledge in the art in any country. In the claims which follow and in the preceding description of the invention, except where the context requires otherwise due to express language or necessary implication, the word 15 “comprise” or variations such as “comprises” or “comprising” is used in an inclusive sense, i.e. to specify the presence of the stated features but not to preclude the presence or addition of further features in various embodiments of the invention.

Claims

1. A gaming machine comprising:a credit input mechanism configured to receive a physical item representing a5 monetary value for establishing a credit balance, the credit balance being increasable and decreasable based at least on wagering activity;a credit meter configured to monitor the credit balance;a manually operable player interface configured to, in accord with the wagering activity, initiate play of a base game;10            an electronic display having a display area, said display area having a plurality ofdisplay positions;a memory storing data indicative of a set of symbols including a plurality of symbols having a particular characteristic;an evaluator configured to monitor the occurrence of a trigger event, and to trigger a 15 feature game in response to the occurrence of a trigger event, said feature game comprising a variable number of free games;a free game counter configured to generate a count representing a number of free games remaining to be played;and wherein said evaluator is configured to revise said free game counter upon the20 occurrence of a defined outcome of a free game and to end the feature game when said count reaches a predetermined end count;wherein, during the feature game, the symbol selector is configured for each free game to:1) hold at least some of the displayed symbols having the particular characteristic 25 appearing on the display;2) remove at least one of the displayed symbols without the particular characteristic from the display;3) select randomly a replacement symbol from the set of symbols to replace a removed symbol without the particular characteristic; and30           4) replace the removed said one of the displayed symbols without the particularcharacteristic with the selected replacement symbol, andwherein the outcome evaluator is configured to make an award upon a matrix of display positions being filled by symbols having the particular characteristic.2026204704   17 Jun 20262.     A gaming machine as claimed in claim 1, wherein the symbol selector selects eachreplacement symbol from an individual reel associated with an individual symbol position.

3. A gaming machine as claimed in claim 1 or claim 2, wherein the award is a highest5 jackpot prize.

4. A gaming machine as claimed in claim 1 or claim 2, wherein the award is a GrandJackpot.

5. A gaming machine according to any one of claims 1 to 4, wherein the outcome10 evaluator is configured to revise the count of the free game counter based on the selected replacement symbol in the outcome of a free game having said particular characteristic and including resetting the count of the free game counter.

6. A gaming machine according to claim 5, wherein the free game counter maintains the15 count of free games to be awarded in the feature game, and wherein a predefined number of free games is initially awarded when the feature game is triggered.

7. A gaming machine according to claim 1, wherein said outcome evaluator is configuredto reset the count of the free game counter based on said another symbol having said20 particular characteristic.

8. A gaming machine according to claim 5, wherein said counter is reset to a predefined number of free games.25   9. A gaming machine according to claim 5, wherein the free game counter is decrementedeach time the outcome of a free game does not have said another symbol with said particular characteristic.

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