U.S. Pat. No. 8,616,954

DETAILED DESCRIPTION OF THE INVENTION

Referring to the drawings, there is shown a gaming system having a game controller arranged to implement a game wherein one or more symbols are retained from a previous game outcome and one or more subsequent game outcomes generated including the retained symbols. The retained symbols from a previous game outcome are selected from symbols which contribute to a winning symbols combination in the previous game outcome. In the subsequent game outcome these symbols can contribute to further winning symbol combinations.

The gaming system can take a number of different forms. In a first form, a stand alone gaming machine is provided wherein all or most components required for implementing the game are present in a player operable gaming machine.

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 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 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 modifiable. For example, the gaming system may operate in stand alone 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 system comprises several core components. At the broadest level, the core components are a player interface50and a game controller60as illustrated inFIG. 1. The player interface is arranged to enable manual interaction between a player and the gaming system and for this purpose includes the input/output components required for the player to enter instructions and play the game and observe the game outcomes.

Components of the player interface may vary from embodiment to embodiment but will typically include a credit mechanism52to enable a player to input credits and receive payouts, one or more displays54, a game play mechanism56including one or more input devices that enables a player to input game play instructions (e.g. to place a wager), and one or more speakers58.

The game controller60is in data communication with the player interface and typically includes a processor62that processes the game play instructions in accordance with game play rules and outputs game play outcomes to the display. Typically, the game play instructions are stored as program code in a memory64but can also be hardwired. Herein the term “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 PC) or a server.

A gaming system in the form of a stand alone gaming machine202is illustrated inFIG. 2. The gaming machine202includes a console12having a display14on which are displayed representations of a game16that can be played by a player. A mid-trim20of the gaming machine202houses a bank of buttons22for enabling a player to interact with the gaming machine, in particular during game play. The mid-trim20also houses a credit input mechanism24which in this example includes a coin input chute24A and a bill collector24B. Other credit input mechanisms may also be employed, for example, a card reader for reading 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 ticket. 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, 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.

A top box26may carry artwork28, 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 panel29of the console12. A coin tray30is mounted beneath the front panel29for dispensing cash payouts from the gaming machine202.

The display14shown inFIG. 2is in the form of a video display unit, particularly a cathode ray tube screen device. Alternatively, the display14may be a liquid crystal display, plasma screen, any other suitable video display unit, or the visible portion of an electromechanical device. The top box26may also include a display, for example a video display unit, which may be of the same type as the display14, or of a different type.

FIG. 3shows a block diagram of operative components of a typical gaming machine which may be the same as or different to the gaming machine ofFIG. 2.

The gaming machine100includes a game controller101having a processor102mounted on a circuit board. Instructions and data to control operation of the processor102are stored in a memory103, which is in data communication with the processor102. Typically, the gaming machine100will include both volatile and non-volatile memory and more than one of each type of memory, with such memories being collectively represented by the memory103.

The gaming machine has hardware meters104for purposes including ensuring regulatory compliance and monitoring player credit, an input/output (I/O) interface105for communicating with peripheral devices of the gaming machine100. The input/output interface105and/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 module113generates random numbers for use by the processor102. Persons skilled in the art will appreciate that the reference to random numbers includes pseudo-random numbers.

In the example shown inFIG. 3, a player interface120includes peripheral devices that communicate with the game controller101comprise one or more displays106, a touch screen and/or buttons107(which provide a game play mechanism), speakers or audio output (not shown), a card and/or ticket reader108, a printer109, a bill acceptor and/or coin input mechanism110and a coin output mechanism111. Additional hardware may be included as part of the gaming machine100, 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 instructions may be used. For example, in some gaming machines a mechanical handle is used to initiate a play of the game.

In addition, the gaming machine100may include a communications interface, for example a network card112. 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 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.

FIG. 4shows a block diagram of the main components of an exemplary memory103. The memory103includes RAM103A, EPROM103B and a mass storage device103C. The RAM103A typically temporarily holds program files for execution by the processor102and related data. The EPROM103B may be a boot ROM device and/or may contain some system or game related code. The mass storage device103C is typically used to store game programs, the integrity of which may be verified and/or authenticated by the processor102using protected code from the EPROM103B or elsewhere.

It is also possible for the operative components of the gaming machine100to be distributed, for example input/output devices106,107,108,109,110,111to be provided remotely from the game controller101.

FIG. 5shows a gaming system200in accordance with an alternative embodiment. The gaming system200includes a network201, which for example may be an Ethernet network. Gaming machines202, shown arranged in three banks203of two gaming machines202inFIG. 5, are connected to the network201. The gaming machines202provide a player operable interface and may be the same as the gaming machines10,100shown inFIGS. 2 and 3, or may have simplified functionality depending on the requirements for implementing game play. While banks203of two gaming machines are illustrated inFIG. 5, banks of one, three or more gaming machines are also envisaged.

One or more displays204may also be connected to the network201. For example, the displays204may be associated with one or more banks203of gaming machines. The displays204may be used to display representations associated with game play on the gaming machines202, and/or used to display other representations, for example promotional or informational material.

In a thick client embodiment, game server205implements part of the game played by a player using a gaming machine202and the gaming machine202implements part of the 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 server206may manage storage of game programs and associated data for downloading or access by the gaming devices202in a database206A. Typically, if the gaming system enables players to participate in a Jackpot game, a Jackpot server207will be provided to perform accounting functions for the Jackpot game. A loyalty program server212may also be provided.

In a thin client embodiment, game server205implements most or all of the game played by a player using a gaming machine202and the gaming machine202essentially provides only the player interface. With this embodiment, the game server205provides the game controller. The gaming machine will receive player instructions, pass these to the game server which will 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 disclosures of which are incorporated herein by reference.

Servers are also typically provided to assist in the administration of the gaming network200, including for example a gaming floor management server208, and a licensing server209to monitor the use of licenses relating to particular games. An administrator terminal210is provided to allow an administrator to run the network201and the devices connected to the network.

The gaming system200may communicate with other gaming systems, other local networks, for example a corporate network, and/or a wide area network such as the Internet, for example through a firewall211.

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 separate server may be provided. For example, the game server205could 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.

The gaming system of the present application implements a gaming method wherein one or more symbols from winning symbols combinations of a game outcome are selected to be retained for inclusion in a symbol set for a subsequently generated game outcome. The retained symbols can contribute to further winning symbol combinations in the subsequent game outcome Embodiments may be applied for a variety of types of games, for example spinning reel, poker or other card dealing games, dice games etc.

The gaming system may implement the gaming method in “feature” game outcomes. For example, one or more feature game outcomes can become available to a player once eligibility criteria are met. For example, a feature game outcome generation sequence may be triggered by a given symbol or symbol combination occurring in a regular game outcome for a base game. Feature game outcomes may be generated as a sequence of “free play” rounds which do not require a wager to be placed. In one variation for the feature game outcomes, a series of feature game outcomes are generated, during which selected symbols are retained. Subsequent feature game outcomes may be generated a number of times until an end condition is met. For example, an end condition may be that a maximum win symbol combination has occurred in the generated game outcome. Alternatively the gaming method may be used for outcomes of regular game play or a player may pay an additional bet to apply the gaming method for a set of game outcomes.

An embodiment of a gaming system for a spinning reel game is illustrated inFIG. 6. (Where possible the same numbering asFIG. 1is used.) The gaming system comprises a game controller60and a player interface50. The game controller60includes a processor62and memory64. Functions implemented in the game controller60include an outcome generator645having a symbol selector640, an outcome evaluator660and a display controller670. The player interface includes a display54and game play mechanism56.

The player inputs game play instructions using the game play mechanism56. For example, the player may select a number of pay lines and enter an amount to wager per pay line. In initial game outcome is generated in response to the player's instructions. To generate the initial outcome the symbol selector640selects symbols from symbol data610which comprises a set of available symbols for each of a plurality of groups615a-d. For example, each group615a615b615c615dmay specify the configuration of one of a plurality of reels, and the symbol selector may be in the form of a reel controller for selecting stop positions for each reel. In an alternative embodiment each group may represent one of a plurality of dice. In a further alternative embodiment only one group of symbols may be provided, for example representing a deck of cards or pool for a lottery draw.

The display controller670is provided with data defining the symbols to display for each group by the symbol selector640this data can also include display positions for each symbol or group of symbols. The display controller displays the selected symbol set in accordance with this data on the display54. Data may also be provided to the display controller by the outcome evaluator660, for example to cause highlighting of prize winning combinations of symbols on the display54. The outcome evaluator660can also be adapted to increment a win meter or award a prize for a winning combination.

The following process occurs where player is eligible for symbols to be retained from a game outcome, for example if the eligibility criteria for feature game outcomes are met. In some embodiments the outcome evaluator660includes a trigger monitor665adapted to determine when the eligibility criteria for feature game outcomes is met, for example for an embodiment where the eligibility criteria is a defined symbol or symbol combination occurring in a base game outcome.

The symbol selector640selects one or more symbols to retain from the symbol set of the game outcome, and stores retained symbol data625in memory64. The symbols selected are symbols which contribute to winning combinations in the game outcome, for example the symbols of a winning win line of the game outcome or selected symbols form the winning win line which contribute to a winning symbols combination.

The symbol selector then selects a further set of symbols, which includes the retained symbols, in accordance with game rules. For example, the symbol selector640selects symbols from symbol data610for each of the plurality of groups615a-drepresenting a reel based on stop positions for the reel. In an embodiment where the retained symbols are held in position and the reels are represented as spinning behind the retained symbols, a symbol set may be selected using the process described above for the initial game outcome and replace symbols from the set with the retained symbols to form the further symbol set including the retained symbols. Alternatively the number of symbols selected from each group may be reduced by the number of retained symbols from that group and the newly selected symbols added to the retained symbols to form the further symbol set.

The display controller670is provided with data defining the symbols to display. For example, in a spinning reel embodiment symbol data may include a graphic icon and display position for each symbol. The display controller670displays the selected symbol set in accordance with this data on the display54as a further game outcome. In some embodiment the retained symbols may be displayed in their original position in each game outcome or may be displayed in designated positions for each symbol group, for example in the bottom lines of the displayed symbol set. The retained symbols remain in the displayed symbol set and can form part of further winning outcome symbol combinations. The outcome evaluator660determines winning symbol combinations in the further game outcome. Data may also be provided to the display controller by the outcome evaluator660, for highlighting of prize winning combinations of symbols on the display54.

The outcome evaluator660can be further adapted to determine credit values payable for the winning game outcomes in accordance with game rules. The outcome evaluator660can also update a player's win meter with the credit values won for a game round. A player's win meter may be updated after each game outcome or at the end of a set of game outcomes, for example at the end of a set of feature game outcomes. The timing of when a player's win meter is updated and which winning outcomes contribute to the credit value added to the win meter are dependent on game rules and may vary between embodiments. For example, where the win meter is updated at the end of a set of game outcomes only winning symbol combinations included in the final game outcome, which will typically include retained symbols, may result in credit value added to the player's win meter. Alternatively, only the highest credit value for a winning symbol combination may be awarded for each game outcome. In other embodiments the player's win meter may be updated each round for every winning symbol combination which occurs. It should be appreciated that by retaining symbols from a winning symbol combination of a previous game outcome in a subsequent game outcome, this increases the likelihood of a further winning symbol combination, earning a higher credit value occurring, in a subsequent game outcome.

The gaming method will now be described in more detail with reference toFIG. 7which is a flow chart of a process for executing feature game rounds for a gaming system as described above. The feature game rounds may be triggered from a base game, for example in response to a defined symbol or symbol combination occurring in the base game. Alternatively the feature game rounds may be triggered randomly independent of any specific occurrence in a base game.

An initial game outcome is generated by selecting710a set of symbols and displaying715the selected symbols as a game outcome. In the illustrated embodiment, if no winning symbol combinations occur in the initial game outcome720the feature game rounds end and the player must start a new game790, which will typically return to the base game. Alternatively, a further initial game outcome may be generated. A player may be allowed a number of initial game outcomes without any winning combinations, say three chances, before the feature rounds end and play returns to the base game.

If one or more winning symbol combinations occur in the initial game outcome720, symbols are selected from the winning symbol combinations to retain730. The symbols to retain are selected in accordance with symbols selection criteria defined in game rules. For example, the selected symbols may be all symbols of winning combinations, symbols contributing to a winning combination, such as all symbols of a pay line which includes a winning combination, or symbols from a single winning combination. Alternatively a player may have some input into the selection of the retained symbols. For example, where two winning symbol combinations occur in an initial game outcome and the symbols from only one winning combination can be retained, the player may be offered the opportunity to select which combination they wish to retain for the subsequent game outcome.

A further set of symbols is selected740, including the retained symbols, and displayed750as a subsequent game outcome. The retained symbols may be displayed in the same display positions in the subsequent game outcome as the previous outcome. Alternatively the retained symbols can be displayed in different symbol positions, with in the displayed subsequent game outcome symbol set, based on game rules. For example, retained symbols may be moved to the lowest display positions in the subsequent game outcome, alternatively the retained symbols can be moved to the top, sides or centre of a displayed symbol set. Alternatively the retained symbols may be randomly allocated to different positions in a subsequent symbol set. The positions for the retained symbols in a subsequent game outcome may vary depending on the embodiment. Further, rules for determining display positions for retained symbols may depend on the game type. For example, for a spinning reel game each retained symbol can be retained in a display position associated with the reel from which the symbol was retained, such that the number of symbols displayed from each reel in each game outcome remains constant.

The display positions for the retained symbols may also be based on how winning symbol combinations are determined for a displayed game outcome. For example, if symbol order is important for a winning symbol combination to occur, such as defined pay lines, then rules for displaying retained symbols in subsequent game outcomes may retain aspects of the retained symbols display order from the previous game outcome. Alternatively, where the position or order of the retained symbols is not important to the game rules for determining winning symbol combinations, for example for a card draw or dice game, then there are no restrictions on the display position for the retained symbols.

The game controller determines whether any winning symbol combinations occur in the subsequent game outcome760. The retained symbols can contribute to winning symbol combinations in the subsequent game outcome. These winning symbol combinations can include the winning symbol combination of the retained symbols from the previous game outcome as well as further winning symbol combinations. Typically a subsequent game outcome will include at least the winning symbol combination comprising the retained symbols. However, in game outcomes where the positions of the retained symbols are altered between the previous and subsequent game outcomes, the winning symbol combination from the previous game outcome may not occur in the subsequent game outcome. The player's win meter may also be updated based on the winning combinations in the game outcome. The game controller can also determine whether the subsequent game outcome is the final game outcome for the sequence770, for example based on the occurrence of an end condition. If the end condition is not met, then the game controller repeats the process of selecting symbols to retain730, selecting740and displaying750further symbol sets, and determining winning combinations760until the end of the game outcome generation sequence.

At the end770of the game outcome generation sequence, any award due the player for the game outcomes can be determined780based on game rules. Once the award is determined this can be added to a player credit balance or paid out to the player and a new game started790. The award may be based on a cumulative win meter value, which is updated for each game outcome of the sequence or based on awards due for one or more winning symbol combinations in the final subsequent game outcome only. The manner in which awards are determined can vary depending on the embodiment implemented.

Persons skilled in the art will also appreciate that the method of the embodiment could be embodied in program code. The program code could be supplied in a number of ways, for example on a computer readable medium, such as a disc or a memory (for example, that could replace part of memory103) or as a data signal (for example, by downloading it from a server).

It will be understood to persons skilled in the art of the invention that many modifications may be made without departing from the spirit and scope of the invention, in particular it will be apparent that certain features of the invention can be combined to form further embodiments.

It is to be understood that, if any prior art publication is referred to herein, such reference does not constitute an admission that the publication forms a part of the common general knowledge in the art, in Australia or any other 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 “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.

Example 1

In the following non limiting example a player is playing a spinning reel game. A player triggers a series of three feature game outcomes from a base game. During the feature game outcomes the play of the game is free.

According to game rules during the feature game outcomes symbols of a winning outcome are held in position and can contribute to further winning combinations in subsequent feature game outcomes. Game rules define that a prize awarded for the feature game outcomes is determined based on the winning combinations appearing in the final feature game outcome.

A game outcome generated for the first free reel spin is illustrated inFIG. 8a. The symbols on the reels801include a winning symbol combination of a royal flush in the form of symbols ‘A’810, ‘K’811, ‘Q’812, ‘J’813and ‘10’814. The credit value of a prize for the flush is one hundred credits. These symbols810-814are held in position for the next free reel spin.

A game outcome generated for the second free reel spin is illustrated inFIG. 8b. The symbols on the reels802include the winning symbol combinations of the royal flush810-814from the first free spin and a new winning symbol combination of a full house in the form of symbols ‘K’820, ‘K’811, ‘J’821, ‘J’813and ‘J’823. The credit value of a prize for the full house is eighty credits. It can be seen from the reels802that two of the symbols ‘K’811and ‘J’813from the winning symbol combination of the previous reel spin outcome are included in the new winning combination. Symbols of both winning combinations are held in position for the next free spin.

A game outcome generated for the third free reel spin is illustrated inFIG. 8c. The symbols on the reels803include the winning symbol combinations of the royal flush and full house from the first and second free spins and a new winning symbol combination of four of a kind in the form of four sixes830-833. The credit value of a prize for the four of a kind is fifty credits.

A prize is awarded for the feature game outcomes based on the three winning symbol combinations, in this case the sum of the credit values for each of the winning combinations. Making the total prize awarded for the feature games two hundred and thirty credits, being the sum of one hundred credits for the flush, eighty credits for the full house and fifty credits for four of a kind. Play can then return to the base game.

In this case the player would have received the same prize value if the prizes for winning combinations in each game outcome were awarded progressively after each feature game outcome for each new winning combination added.

Example 2

In the following non limiting example a player is playing a spinning reel game. A player triggers a series of four feature game outcomes from a base game. During the feature game outcomes the play of the game is free.

According to game rules during the feature game outcomes symbols of a winning outcome are dropped to positions at the bottom for subsequent outcomes and can contribute to further winning combinations in subsequent feature game outcomes. Game rules define that a prize awarded for the feature game outcomes is determined based on the winning combinations appearing in the final feature game outcome.

A game outcome generated for the first free reel spin is illustrated inFIG. 9a. The symbols on the reels901include a winning symbol combination of a royal flush in the form of symbols ‘A’910, ‘K’911, ‘Q’912, ‘J’913and ‘10’914. The credit value of a prize for the flush is one hundred credits. These symbols910-914are dropped to bottom positions of the outcome for the next free reel spin.

A game outcome generated for the second free reel spin is illustrated inFIG. 9b. The symbols on the reels902include the winning symbol combinations of the royal flush910-914from the first free spin in a pay line at the bottom of the outcome and a new winning symbol combination of a full house in the form of symbols ‘A’910, ‘A’920, ‘A’921, ‘10’922and ‘10’914. The credit value of a prize for the full house is eighty credits. It can be seen from the reels902that two of the symbols ‘A’910and ‘10’914from the winning symbol combination of the previous reel spin outcome are included in the new winning combination.

The symbols of both winning combinations now pile up at the bottom of the outcome for the next free spin. Note that in this case the change of symbols positions destroys the full house of the second winning combination leaving only a pair ‘A’920, ‘A’921and ‘10’922on a pay line. However these symbols920-922remain and can contribute to a further winning combination in a subsequent feature game outcome.

A game outcome generated for the third free reel spin is illustrated inFIG. 9c. The symbols on the reels903include the winning symbol combination of the royal flush910-914from the first free spin in a pay line at the bottom of the outcome and a new winning symbol combination of a pair in the form of symbols ‘A’930and ‘A’931. The credit value of a prize for a pair is ten credits. The symbols of the pair are dropped and pile up at the bottom of the outcome for the next free spin.

A game outcome generated for the fourth free reel spin is illustrated inFIG. 9d. The symbols on the reels904include the winning symbol combination of the royal flush910-914from the first free spin in a pay line at the bottom of the outcome. Due to the pair symbols930,931piling up at the bottom of the outcome, a new winning symbol combination of four of a kind in the form of symbols ‘A’930, ‘A’920, ‘A’921, and ‘A’931. The credit value of a prize for four of a kind is fifty credits. A prize of ten credits can also be paid for the WILD symbol940appearing in the outcome.

A prize is awarded for the feature game outcomes based on the winning symbol combinations appearing in the final game outcome904, in this case the sum of the credit values of one hundred credits for the flush, fifty credits for four of a kind and ten credits for the wild. Making the total prize awarded for the feature games one hundred and ninety credits. Play can then return to the base game.

In this case the player would have received a different prize value if the prizes for winning combinations in each game outcome were awarded progressively after each feature game outcome for each new winning combination added.

Example 3

In the following non limiting example a player is playing a spinning reel game. A player triggers a series of three feature game outcomes from a base game. During the feature game outcomes the play of the game is free.

According to game rules during the feature game outcomes symbols of the highest prize value winning outcome are held in position and can contribute to further winning combinations in subsequent feature game outcomes. If a higher value winning outcome occurs, then the symbols of this further higher value winning outcome are held for subsequent game outcomes. Game rules define that a prize awarded for the feature game outcomes is determined based on winning symbol combinations appearing in the final feature game outcome.

A game outcome generated for the first free reel spin is illustrated inFIG. 10a. The symbols on the reels1001include a winning symbol combination of in the form of two ‘cherries’ symbols1010,1011and a ‘WILD’1012. The credit value of a prize for this combination is thirty credits. These symbols1010-1012are held in position for the next free reel spin.

A game outcome generated for the second free reel spin is illustrated inFIG. 10b. The symbols on the reels1002include the winning symbol combination1010-1012from the first free spin and a new winning symbol combination of two ‘orange’ symbols1020,1021and a ‘WILD’1022. The credit value of a prize for this combination is twenty credits. As the first symbol combination has a higher credit value the second winning symbol combination1020-1022is dropped and only the first symbol combination held for the next free spin.

A game outcome generated for the third free reel spin is illustrated inFIG. 10c. The symbols on the reels1003include the winning symbol combinations the winning symbol combination1010-1012from the first free spin and a new winning symbol combination of three ‘apple’ symbols1030-1032. The credit value of a prize for the new symbol combination1030-1032is fifty credits.

A prize is awarded for the feature game outcomes based on the two winning symbol combinations in the final outcome, in this case eighty credits being the sum of the credit values for each of the winning combinations. Play can then return to the base game.

In this case the held winning symbol combination sets a minimum prize value for the feature game outcomes.

In an alternative award scheme a cumulative prize may be determined based on the winning combinations appearing in each feature game outcome. For example, accumulating thirty credits for the outcome of the first reel spin, fifty credits for the outcome of the second reel spin, and eighty credits for the outcome of the third reel spin to give a total of one hundred and sixty credits for the feature game outcomes.

Example 4

In the following non limiting example a player is playing a spinning reel game. A player triggers a series of three feature game outcomes from a base game. During the feature game outcomes the play of the game is free.

According to game rules during the feature game outcomes symbols of the highest prize value winning outcome are held for a subsequent game outcome. The held symbols are dropped to display positions at the bottom of the game outcome where they can contribute to further winning combinations in subsequent feature game outcomes. If a higher value winning outcome occurs, then the symbols of this further higher value winning outcome are held for subsequent game outcomes. Game rules define that a prize awarded for the feature game outcomes is determined based on winning symbol combinations appearing in the final feature game outcome.

A game outcome generated for the first free reel spin is illustrated inFIG. 11a. The symbols on the reels1101include a winning symbol combination of in the form of two ‘cherries’ symbols1110,1111and a ‘WILD’1112. The credit value of a prize for this combination is thirty credits. These symbols1110-1112are dropped to bottom positions for the next free reel spin.

A game outcome generated for the second free reel spin is illustrated inFIG. 11b. The symbols on the reels1102includes a new winning symbol combination of three ‘cherries’ symbols1120-1122. The credit value of a prize for this combination is thirty credits. The symbols1102also include a new winning symbol combination comprising one ‘cherries’ symbol1120from the new winning symbol combination and the symbols1110-1112retained from the first free spin to give a combination of three ‘cherries’ symbols1120,1110.1111and ‘WILD’ symbol1112. The credit value of a prize for this combination is fifty credits. This new symbol combination is retained for the next free spin as it has a higher credit value than the other new symbol combination.

A game outcome generated for the third free reel spin is illustrated inFIG. 11c. The symbols on the reels1003includes the winning symbol combination retained from the second outcome and a new winning symbol of three ‘orange’ symbols1130-1132. The credit value of a prize for the new symbol combination1130-1132is thirty credits.

A prize is awarded for the feature game outcomes based on the two winning symbol combinations in the final outcome, in this case eighty credits being the sum of the credit values for each of the winning combinations. Play can then return to the base game.

In this case the held winning symbol combination sets a minimum prize value for the feature game outcomes.

In an alternative award scheme a cumulative prize may be determined based on the winning combinations appearing in each feature game outcome. For example, accumulating thirty credits for the outcome of the first reel spin, eighty credits for the outcome of the second reel spin, and eighty credits for the outcome of the third reel spin to give a total of one hundred and ninety credits for the feature game outcomes.

Example 5

In the following non limiting example a player is playing a game have a base game from which feature game outcomes can be triggered. The feature game outcomes are card deal outcomes. The base game may also be a card dealing game or may be another type of game. During the feature game outcomes the play of the game is free.

According to game rules during the feature game outcomes symbols of the highest prize value winning outcome are held for a subsequent game outcome. Winning symbol combinations are not dependent on the order in which the symbols appear in a dealt hand. The held symbols can contribute to further winning combinations in subsequent feature game outcomes. Game rules define that a prize awarded for the feature game outcomes is determined based on winning symbol combinations appearing in the final feature game outcome.

A game outcome generated for the first deal is illustrated inFIG. 12a. The five dealt cards1201-1205include a winning symbol combination of in the form of a pair of aces1202,1205. The credit value of a prize for this combination is thirty credits. These cards1202,1205are held for a subsequent deal.

A game outcome generated for the second deal is illustrated inFIG. 12b. This outcome includes the retained aces1202,1205and three new cards1206-1208which includes a further winning combination of a pair of tens1207,1208. The credit value of a prize for this further combination is thirty credits. The pair of aces1202,1205and pair of tens1207,1208are held for a subsequent deal.

A game outcome generated for the second deal is illustrated inFIG. 12c. This outcome includes the retained aces1202,1205and tens1207,1208, and a new card1209which is a further ace. The game outcome includes a winning combination of a full house comprising three aces1202,1205,1209and pair of tens1207,1208. The prize for a full house is one hundred credits. The prize value of one hundred credits is awarded to the player and play continues with the base game.

Example 6

In the following non limiting example a player is playing a spinning reel game. A player triggers a series of three feature game outcomes from a base game. During the feature game outcomes the play of the game is free.

According to game rules during the feature game outcomes symbols of one winning outcome are held in position and can contribute to further winning combinations in subsequent feature game outcomes. Where more than one winning symbol combination occurs in an outcome the player can choose which outcome to retain. Game rules define that a prize awarded for the feature game outcomes is determined based on winning symbol combinations appearing in the final feature game outcome.

A game outcome generated for the first free reel spin is illustrated inFIG. 13a. The symbols on the reels1301include a winning symbol combination of in the form of two ‘cherries’ symbols1310,1311. The credit value of a prize for this combination is ten credits. As this is the only winning symbol combination, these symbols1310,1311are held in position for the next free reel spin.

A game outcome generated for the second free reel spin is illustrated inFIG. 13b. The symbols on the reels1302include a first winning symbol combination of the two ‘cherries’ symbols1310,1311from the first free spin and a ‘WILD’ symbol1320, and a second winning symbol combination of three ‘orange’ symbols1321-1323. The credit value of a prize for each of the first and second combinations is thirty credits. The player can then select one of the symbol combinations to retain for the next outcome. The player chooses to retain the second winning symbol combination of three orange symbols1321-1323so this symbol combination is held for the next free spin.

A game outcome generated for the third free reel spin is illustrated inFIG. 13c. The symbols on the reels1303include the winning symbol combination of four ‘orange’ symbols, comprising the three retained ‘orange’ symbols1321-1323and a new ‘orange’ symbol1340. The credit value of a prize for this symbol combination is fifty credits. The game outcome includes no other winning symbol combinations.

A prize is awarded for the feature game outcomes based on the winning symbol combinations in the final outcome, in this case so the prize of fifty credits for the one final winning outcome.

In this case the player selects the held winning symbol combination which sets a minimum prize value for the feature game outcomes when more than one winning outcome occurs. This enables the player to have greater involvement in the feature game outcomes and potentially increase the player enjoyment.

In an alternative award scheme a cumulative prize may be determined based on the winning combinations appearing in each feature game outcome. For example, accumulating ten credits for the outcome of the first reel spin, sixty credits for the outcome of the second reel spin, and fifty credits for the outcome of the third reel spin to give a total of one hundred and twenty credits for the feature game outcomes.