Progressive Jackpot incrementing system

Abstract

A gaming system and a method of operating a bonus prize awarding system, the system comprising a plurality of electronic gaming console having a console cabinet 10 including a prize display 12, a coin entry slot 13, a pay out tray 14 and internally mounted game control processor circuits. A video game is provided for play on the console in which images of objects (balls) are dropped through a series of obstacles (pins) and eventually fill a number of containers. Prizes are paid according to either the number of balls which are in each container at the end of the ball drop and/or the manner in which the pins are hit, and bonus prizes are increased progressively upon the occurrence of predetermined game events within the game or external to the game.

1 . A method of awarding a feature or bonus in a game, played on an electronic gaming console comprising credit means, reward means, game control means, display means, and player input controls, the control means being responsive to the credit means and the player input controls to play a game which is displayed on the display means and if a winning event occurs, a player reward is awarded by the reward means, wherein the game being played on the gaming console provides a video display of a labyrinth of pins and the player input controls allow the player to initiate the motion of ball images on the display, player rewards being awarded when the ball images come to rest in predetermined prize winning locations, the game being characterized in that a variable value bonus prize is awarded when a predetermined triggering event occurs, the value of the bonus prize for a future instance of the bonus prize award being altered in response to the occurrence of a predetermined prize altering event in respect of a current instance of the game.  
     
     
         2 . A method of awarding a feature or bonus in a game for an electronic gaming console comprising credit means, reward means, game control means, display means and player input controls, the control means being responsive to the credit means and the player input controls to play a game which is displayed on the display means and, if a winning event occurs, a player reward is awarded by the reward means, wherein the game played on a gaming console provides a video display of a labyrinth of pins and the player input controls allow the player to initiate the motion of ball images on the display, player rewards being awarded when the ball images come to rest in predetermined prize winning locations, the game being characterized in that, a variable value bonus prize is awarded when a predetermined triggering event occurs, and when a predetermined prize altering event occurs, a level of bonus being played for in a current instance of the game is altered.  
     
     
         3 . The method as claimed in  claim 1  or  2 , wherein the pre-determined triggering event is an event occurring in the current instance of the game.  
     
     
         4 . The method as claimed in any one of claims  1 ,  2  or  3 , wherein the predetermined triggering event is independent of the predetermined prize altering event.  
     
     
         5 . The method as claimed in any one of claims  1 ,  2  or  3 , wherein the predetermined triggering event is related to the predetermined prize altering event.  
     
     
         6 . The method as claimed in  claim 5 , wherein there are a plurality of possible predetermined prize altering events and the predetermined triggering event is one of events that constitute the possible predetermined prize altering events.  
     
     
         7 . The method as claimed in  claim 6 , wherein there are a plurality of possible triggering events which constitute a subset of the possible predetermined prize altering events.  
     
     
         8 . The method as claimed in  claim 7 , wherein each predetermined prize altering event is a predetermined triggering event of the current instance of the game.  
     
     
         9 . The method as claimed in any one of  claims 1  to  4 , wherein the predetermined prize altering event or events, are events independent of the current instance of the game.  
     
     
         10 . The method as claimed in  claim 9 , wherein the predetermined prize altering event or events are related to the placing of a bet in respect of the current instance of the game.  
     
     
         11 . The method as claimed in  claim 9  or  10 , wherein the predetermined prize altering event or events are otherwise non-winning events.  
     
     
         12 . The method as claimed in any one of  claims 1  to  11 , wherein the predetermined triggering event is a random event.  
     
     
         13 . The method as claimed in any one of  claims 1  to  11 , wherein values are assigned to one or more of the pins, such that the bonus for future instances of the game is increased by the respective value if a pin is struck by a ball.  
     
     
         14 . The method as claimed in  claim 13 , wherein the number of pins having bonus increasing values assigned to them is related to the number of credits bet.  
     
     
         15 . The method as claimed in any one of  claims 1  to  14 , wherein the game is characterised in that a plurality of targets are provided and values are assigned to the targets such that if a ball comes to rest in or on the target, the bonus for future instances of the game is increased by the respective value.  
     
     
         16 . The method as claimed  claim 15 , wherein the number of targets provided in a game is related to the number of credits bet.  
     
     
         17 . The method as claimed in  claim 15  or  16 , wherein the target is of a form selected from a set including cups, buckets and pairs of pins.  
     
     
         18 . The method as claimed in any one of  claims 1  to  17 , wherein holes are provided in the pin pattern, such that balls may fall into the holes during a game and the occurrence of a ball falling down one of the holes will increment the bonus prize for future instances of the game.  
     
     
         19 . The method as claimed in  claim 18 , wherein, after dropping down a hole, the ball will re-appear in the game to continue the ball drop.  
     
     
         20 . The method as claimed in  claim 18 , wherein, after dropping down a hole, the ball will re-appear in the game to represent the incrementing bonus prize.  
     
     
         21 . The method as claimed in  claim 18 , wherein, after dropping down a hole, the ball will not re-appear in the game.  
     
     
         22 . The method as claimed in any one of  claims 1  to  21 , wherein balls of different colours are provided and when a ball is dropped, the bonus is increased by a value which is a function of ball colour.  
     
     
         23 . The method of  claim 22 , wherein the bonus is increased by a predetermined amount when a ball of a predetermined colour is dropped.  
     
     
         24 . The method of  claim 23 , wherein the bonus is increased when the ball of predetermined colour interacts with another game feature.  
     
     
         25 . The method of  claim 24 , wherein the bonus is incremented when the ball of predetermined colour falls into a hole.  
     
     
         26 . The method as claimed in claims  4 ,  5 ,  6  or  7 , wherein at least one ball changes colour as it drops through the labyrinth.  
     
     
         27 . The method as claimed in any one of  claims 1  to  21 , wherein at least one ball changes the colour of any pins that it hits, as it drops through the labyrinth, to its own colour and the bonus is increased by a predetermined value when a predetermined number of pins change colour, or change to a predetermined colour.  
     
     
         28 . The method as claimed in  claim 22 , wherein at least one ball, if it drops into a container, changes the colour of all other balls in that same container at the end of the game and the bonus is increased by a predetermined value.  
     
     
         29 . The method as claimed in any one of  claims 1  to  21 , wherein balls of different sizes are provided and the dropping of a ball of a predetermined size will increase the bonus by a predetermined value.  
     
     
         30 . The method as claimed in  claim 29 , wherein a bonus meter is increased by a value according to the size of a ball dropped.  
     
     
         31 . The method as claimed in  claim 27 , wherein larger balls are provided which will not fit between some pins or into some holes or containers such that the large balls may block holes or containers that they come to rest against or may knock out pins that they hit and whereby only small balls will increase the bonus.  
     
     
         32 . The method as claimed in any one of  claims 1  to  21 , wherein balls landing in outside buckets each serve to increase the bonus by a predetermined value.  
     
     
         33 . The method of  claim 23 , wherein the position from which the balls are dropped is variable from game to game and within a game.  
     
     
         34 . The game console of  claim 33 , wherein the position from which the ball is dropped is selected at random by the control means.  
     
     
         35 . The method of  claim 33 , wherein the position from which the ball is dropped is selected by the player using the player controls.  
     
     
         36 . The method as claimed in any one of  claims 1  to  21 , wherein, the game permits a varying the number of active balls to be purchased and dropped, while maintaining a constant total number of balls being dropped from game to game, the total number of balls being independent of the number of active balls dropped.  
     
     
         37 . The method as claimed in  claim 36 , wherein the balls not purchased by the player are available to increase the bonus meter.  
     
     
         38 . The method as claimed in any one of  claims 1  to  21 , wherein each ball has a plurality of possible associated functions or characteristics one of which causes the bonus to increase.  
     
     
         39 . The method as claimed in  claim 38 , wherein the functions or characteristics associated with the balls may be varied from game to game.  
     
     
         40 . The method as claimed in  claim 38 , wherein the functions or characteristics associated with the balls may be selected by the player.  
     
     
         41 . The method as claimed in any one of  claims 1  to  21 , wherein different shaped balls are provided such that the shape of the balls are matched to holes and only balls with matching shapes can fall into a respective hole.  
     
     
         42 . The method as claimed in  claim 41 , wherein certain shaped holes will serve to increment the progressive when the appropriately-shaped ball drops into them.  
     
     
         43 . The method as claimed in  claim 42 , wherein the pins that the ball hits change colour or are lit to mark the path of the ball.  
     
     
         44 . The method as claimed in  claim 43 , wherein the lit pins, when hit, will alter the progressive while unlit pins when hit do not.  
     
     
         45 . The method as claimed in  claim 44 , wherein the lit pins indicate the amount by which the bonus will be increased.  
     
     
         46 . The method of  claim 43 , wherein the lit pins may be retained from one game to the next.  
     
     
         47 . The method as claimed in any one of  claims 1  to  21 , wherein holes are provided and when balls drop into the holes the bonus is increased.  
     
     
         48 . The method as claimed in  claim 47 , wherein the balls that drop into holes are transformed to another location, and the transformed ball is channelled into a container.  
     
     
         49 . The method of  claim 48 , wherein the container is a jackpot bucket that is representative of the amount by which the bonus has been increased.  
     
     
         50 . The method as claimed in  claim 47 , wherein the transformed ball appears coming out of another hole.  
     
     
         51 . The method as claimed in  claim 47 , wherein the transformed ball re-appears in other section of the screen.  
     
     
         52 . The method as claimed in any one of  claims 1  to  21 , wherein some balls are provided with indicia where the indicia are numbers and, the bonus is increased by the amount dictated by the number on the numbered balls when the balls perform a bonus increasing function.  
     
     
         53 . The method as claimed in  claim 47 , wherein at least one hole is provided which disappears or closes up as soon as a ball drops into it.  
     
     
         54 . The method as claimed in any one of  claims 1  to  21 , wherein at least one ball is provided which will enable and/or disable the increasing of the bonus.  
     
     
         55 . The method as claimed in any one of  claims 1  to  21 , wherein at least one ball is provided which knocks down pins, creating pin holes where the pins were located and can fall down the pin holes to increase the bonus.  
     
     
         56 . The method as claimed in  claim 47 , wherein at least one ball is a larger sized ball relative to the remaining balls such that the larger ball is less likely to fall down holes.  
     
     
         57 . The method as claimed in any one of  claims 1  to  21 , wherein the configuration of the labyrinth of pins is varied depending upon the current level of the bonus.  
     
     
         58 . The method as claimed in  claim 57 , wherein the number of rows of pins is variable from game to game, depending upon the level of the bonus.  
     
     
         59 . The method as claimed in any one of  claims 1  to  21 , wherein one or more of the pins are bonus pins, such that the bonus is increased if the bonus pin is struck by a ball.  
     
     
         60 . The method as claimed in  claim 59  wherein the number of bonus pins is related to the number of credits bet.  
     
     
         61 . The method as claimed in any one of  claims 1  to  21 , wherein selection of the amount by which the bonus will be increased is determined according to how the pins are struck by each ball dropped.  
     
     
         62 . The method as claimed in any one of  claims 1  to  21 , wherein the increasing of the level of bonus being played for depends upon how the pins are struck.  
     
     
         63 . The method as claimed in  claim 62 , wherein at least one pin is associated with a bonus whereby the bonus is increased if the pin is hit by a plurality of balls.  
     
     
         64 . The method as claimed in  claim 63 , wherein the number of balls required to hit the pin for the bonus to increase may be varied from game to game.  
     
     
         65 . The method as claimed in  claim 64 , wherein the number of balls required to hit the pin for the bonus to be increased may be selected by the player.  
     
     
         66 . The method as claimed in  claim 65 , wherein the bonus is increased when a pattern of pins is hit, the pattern being selected as one of, a row, a diagonal, or a diamond shape.  
     
     
         67 . The method as claimed in  claim 66 , wherein pattern of pins can vary from game to game.  
     
     
         68 . The method as claimed in any one of  claims 1  to  21 , wherein the level of bonus being played for, depends upon how the pins are struck.  
     
     
         69 . The method of  claim 68 , wherein at least one pin is provided which, on each occasion it is hit, becomes lit and changes the level of bonus being played for.  
     
     
         70 . The method as claimed in any one of  claims 1  to  21 , wherein at least one pin is provided which will swallow or capture a balls when hit by a ball will swallow or capture the ball and increases the bonus.  
     
     
         71 . The method as claimed in any one of  claims 1  to  21 , wherein at least one pin is provided which will release balls when hit and simultaneously increases the bonus.  
     
     
         72 . The method as claimed in any one of  claims 1  to  21 , wherein at least one pin is provided which, on each occasion it is hit, it becomes lit and increases the bonus.  
     
     
         73 . The method as claimed in any one of  claims 1  to  21 , wherein at least one pin is provided which, on each occasion it is hit, it changes colour and increases the bonus when a certain colour is achieved.  
     
     
         74 . The method of any one of  claims 1  to  21 , wherein at least one pin is provided which, on each occasion it s hit, changes colour and changes the level of bonus being played for, when a certain colour is achieved.  
     
     
         75 . The method as claimed in any one of  claims 1  to  21 , wherein at least one pin is provided which, on each occasion it is hit, it records the number of hits and increases the bonus when a predetermined count is reached.  
     
     
         76 . The method as claimed in  claim 75 , wherein at least one pin is provided which, on each occasion it is hit, increments a counter and when a predetermined count is reached, the player is established as being eligible to win the bonus.  
     
     
         77 . The method as claimed in any one of  claims 1  to  21 , wherein a plurality of pins is provided which each have different colours and when pins having a predetermined combination of colours are all lit, the bonus is increased.  
     
     
         78 . The method as claimed in any one of  claims 1  to  21 , wherein at least one pin is provided which has a hole in it for the ball to pass, and the bonus is increased when a ball passes through the pin.  
     
     
         79 . The method of any one of  claims 1  to  21 , wherein at least one pin is provided which has in it, for the ball to pass and the level of bonus being played for is increased if the ball passes through the pin.  
     
     
         80 . The method as claimed in any one of  claims 1  to  21 , wherein a pattern of pins is provided which randomly flash during a ball drop sequence and the bonus is increased if a pin is struck by a ball while the pin is flashing.  
     
     
         81 . The method as claimed in any one of  claims 1  to  21 , wherein at least one pin is provided which has a number on it representing an amount by which the bonus will be increased when the pin is hit by a ball.  
     
     
         82 . The method as claimed in any one of  claims 1  to  21 , wherein at least one pin is provided which has a number on it representing a level of bonus that will be awarded when the pin is hit by a ball.  
     
     
         83 . The method as claimed in any one of  claims 1  to  21 , wherein at least one pin is provided which is capable of being lit and has a number on it representing an amount by which the bonus is increased when the pin is hit while lit.  
     
     
         84 . The method as claimed in any one of  claims 1  to  21 , wherein at least one pin is provided which is capable of being lit and has a number on it representing the level of bonus that will be awarded when the pin is hit while lit.  
     
     
         85 . The method as claimed in any one of  claims 1  to  21 , wherein at least one group of pins is provided, such that when all pins in the group are hit the bonus is increased.  
     
     
         86 . The method as claimed in any one of  claims 1  to  21 , wherein at least one group of pins is provided in which each of the pins is capable of being lit, such that when all pins in the group are hit while lit the bonus is increased.  
     
     
         87 . The method as claimed in any one of  claims 1  to  21 , wherein at least one pin is provided which is sticky such that if a ball hits the pin, the ball will stick and stay on the pin, and for every game that the ball remains stuck the bonus is increased.  
     
     
         88 . The method as claimed in  claim 87 , wherein the ball is stuck to the at least one sticky pin, another ball is required to hit the stuck ball in order to dislodge it.  
     
     
         89 . The method as claimed in any one of  claims 1  to  21 , wherein, at least one bonus pin is provided such that, if a predetermined number of bonus pins are hit, or a bonus pin is hit, a predetermined number of times, the bonus will be increased.  
     
     
         90 . The method as claimed in  claim 89 , wherein when a ball hits the bonus pin, it will skip to another position on the screen at which a jackpot is awarded.  
     
     
         91 . The method as claimed in any one of  claims 1  to  21 , wherein a number of holes are located amongst the pins such that when a ball passes over a hole, it causes the bonus to increase and the ball enters the hole to be removed from the game.  
     
     
         92 . The method as claimed in  claim 91 , wherein the number and/or position of holes amongst the pins may be varied from game to game.  
     
     
         93 . The method as claimed in  claim 92 , wherein the number and/or position of holes amongst the pins may be selected by the player.  
     
     
         94 . The method as claimed in any one of  claims 1  to  21 , wherein a plurality of targets are provided such that if a ball comes to rest in or on the target, the bonus is increased.  
     
     
         95 . The method as claimed in  claim 94 , wherein the target is a surface of an object.  
     
     
         96 . The method as claimed in  claim 94 , wherein the target is one of the prize winning locations.  
     
     
         97 . The method as claimed in  claim 86 , wherein, the prize winning locations are containers.  
     
     
         98 . The method as claimed in  claim 87 , wherein the number of containers provided is related to the number of credits bet.  
     
     
         99 . The method as claimed in any one of  claims 1  to  21 , wherein the position of bonus increasing locations may be varied from game to game.  
     
     
         100 . The method as claimed in  claim 97 , wherein the position of bonus increasing locations may be selected by the player.  
     
     
         101 . The method as claimed in any one of  claims 1  to  21 , wherein the amount by which the bonus is increased depends on how the bonus locations are struck.  
     
     
         102 . The method as claimed in  claim 101 , wherein at least one bonus increasing location requires more than one ball to come to rest in the location before the bonus will be increased.  
     
     
         103 . The method as claimed in any one of  claims 1  to  21 , wherein the number of balls required to come to rest in the at least one bonus increasing location before a bonus will be increased may be varied from game to game.  
     
     
         104 . The method as claimed in  claim 103 , wherein the number of balls required to come to rest in the at least one prize winning location before a bonus will be increased may be selected by the player.  
     
     
         105 . The method as claimed in any one of  claims 1  to  21 , wherein one or more containers are provided such that the bonus is increased if the container or containers are filled in a pre-determined way.  
     
     
         106 . The method as claimed in  claim 105 , wherein the bonus is increased if a predetermined number of balls are caught in a predetermined set of one or more containers.  
     
     
         107 . The method as claimed in  claim 105 , wherein the number of balls required to be caught and the composition of the set of containers may vary from game to game.  
     
     
         108 . The method as claimed in  claim 107 , wherein the number of balls required to be caught and the composition of the set of containers may vary depending upon the level of bonus being played for.  
     
     
         109 . The method as claimed in  claim 107 , wherein the number of balls required to be caught and the composition of the set of containers may be selected by the player.  
     
     
         110 . The method as claimed in  claim 105 , wherein at least one container is a bonus container which causes the bonus to increase when a ball enters the container, the container having a closable cover which prevents balls from increasing the bonus when it is closed, the lid being opened and closed by predetermined trigger conditions.  
     
     
         111 . The method as claimed in  claim 110 , wherein the number of containers having covers and the number of triggers which open and close them may vary from game to game.  
     
     
         112 . The method as claimed in  claim 110 , wherein the number of containers having covers and the numbers of triggers which open and close them may be selected by the player.  
     
     
         113 . The method as claimed in any one of  claims 1  to  21 , wherein, when an animated object is provided such that that when the animated object catches a ball it moves the ball to a jackpot location.  
     
     
         114 . The method as claimed in  claim 105 , wherein balls may be held and accumulated in at least one container over a number of games to increase the bonus.  
     
     
         115 . The method as claimed in  claim 114 , wherein the ability to accumulated balls over a number of games to increase the bonus may be selected by the player.  
     
     
         116 . The method as claimed in  claim 105 , wherein the level of bonus being played for is a function of the number of credits bet.  
     
     
         117 . The method as claimed in  claim 97  wherein, at least one container is a bonus increasing container which moves position as the balls drop to provide a moving target.  
     
     
         118 . The method as claimed in  claim 97 , wherein the accumulated bonus is increased by an amount related to the number of balls which are in each container at the end of the ball drop.  
     
     
         119 . The method as claimed in any one of  claims 1  to  21 , wherein a plurality of ball types are provided and the level of bonus being played for is determined according to the type of balls dropped.  
     
     
         120 . The method as claimed in  claim 119 , wherein the balls are marked with indicia and the amount by which a progressive will increment is determined according to the indicia on the balls which are in any container.  
     
     
         121 . The method as claimed in  claim 120 , wherein the indicia are numbers.  
     
     
         122 . The method as claimed in  claim 121 , wherein the numbers represent the amount by which the bonus will increase.  
     
     
         123 . The method as claimed in  claim 121 , wherein the numbers represent an amount by which the bonus level associated with the container is increased.  
     
     
         124 . The method as claimed in  claim 123 , wherein changing the credit bet by a player changes the size of the units by which the bonus will be increased.  
     
     
         125 . The method as claimed in  claim 124 , wherein the larger the credit bet by a player the larger the unit increase applied to the bonus.  
     
     
         126 . The method as claimed in  claim 125 , wherein the unit size increase varies linearly with credits bet.  
     
     
         127 . The method as claimed in any one of  claims 1  to  21 , wherein a plurality of ball types are provided and the level by which a bonus will increase is determined according to the type of balls dropped.  
     
     
         128 . The method as claimed in any one of  claims 1  to  21 , wherein the game has a number of bonus zones each offering a different level of jackpot to be played for.  
     
     
         129 . The method as claimed in  claim 128 , wherein the number and locations of the bonus zones may be varied from game to game.  
     
     
         130 . The method as claimed in  claim 129 , wherein the number and locations of the bonus zones may be selected by the player.  
     
     
         131 . The method as claimed in  claim 130 , wherein the number and locations of the bonus zones is selected by the size of the bet wagered by the player on the particular game.  
     
     
         132 . The method as claimed in  claim 97 , wherein when a bonus is awarded the bonus level being played for changes.  
     
     
         133 . The gamin console as claimed in any one of  claims 1  to  21 , wherein the game has a number of bonus zones, each offering a different amount by which the progressive will be increased.  
     
     
         134 . The method as claimed in any one of  claims 1  to  21 , wherein an additional game is provided as a feature game associated with the base game, where the feature game being an independent game, a predetermined trigger condition or award causing the feature game to run, and if a winning condition is achieved in the feature game, the feature game revealing a bonus condition.  
     
     
         135 . The method as claimed in  claim 134 , wherein the bonus condition is an award of a prize.  
     
     
         136 . The method as claimed in  claim 134 , wherein the bonus condition is a win multiplier which multiplies a prize already won.  
     
     
         137 . The method as claimed in  claim 134 , wherein the bonus condition is a number of free games.  
     
     
         138 . The method as claimed in  claim 134 , wherein the bonus condition is the awarding of one or more extra balls to drop in the base game.  
     
     
         139 . The method as claimed in  claim 134 , wherein the bonus condition causes a change in the game structure.  
     
     
         140 . The method as claimed in  claim 134 , wherein the trigger condition to run the feature game is achieved by the collection of one or more balls in a predetermined container.  
     
     
         141 . The method as claimed in  claim 135 , wherein the bonus condition is the increasing of the bonus available for future bonus awards.  
     
     
         142 . The method as claimed in any one of  claims 1  to  21 , wherein the structure of the game is player selectable.  
     
     
         143 . The method as claimed in any one of  claims 1  to  21 , wherein when a bonus is awarded the prizes associated with a particular container become larger.  
     
     
         144 . The method as claimed in any one of  claims 1  to  21 , wherein a slot reel is activated by a ball or triggering event to provide a multiplier, or bonus trigger determined by the stopping position of the reel.  
     
     
         145 . The method as claimed in any one of  claims 1  to  21 , wherein a chocolate wheel is activated by a ball or other means to provide a multiplier, bonus or trigger determined by the stopping position of the wheel.  
     
     
         146 . The method as claimed in any one of  claims 1  to  21 , wherein a spinning reel game played above the pins such that when a winning combination occurs on the reels, coins come out from below the reels and drop into the pins such that the base game determines the prize,  
     
     
         147 . The method as claimed in any one of  claims 1  to  21 , wherein a feature game element is used to determine the base game structure.  
     
     
         148 . The method as claimed in  claim 147 , wherein the prize values, position of holes, number of pins, and pin layout are determined by the feature game.  
     
     
         149 . The method as claimed in  claim 147 , wherein containers have multipliers associated with them and when a win occurs on a feature game, a ball is dropped through the pins to determine how much the win will be multiplied by.  
     
     
         150 . A gaming system which includes a plurality of electronic gaming machines, each gaming machine having a display means and a game control means arranged to control images displayed on the display means, the game control means of each machine being arranged to play a game wherein one or more random events are caused to be displayed on the display means and, if a predefined winning event occurs, the machine awards a prize, the gaming system being characterized in that it includes a progressive meter to which each of the gaming machines is linked such that the progressive meter is altered by the occurrence of predetermined prize altering events during the playing of a game on any one of the gaming machines.  
     
     
         151 . The gaming system as claimed in  claim 150 , wherein a variable value bonus prize is awarded when a predetermined triggering event occurs, and when the predetermined prize altering event occurs, a level of bonus being played for in a current or future instance of the game is altered.  
     
     
         152 . The gaming system as claimed in  claim 150  or  151 , wherein each participating gaming machine plays a game selected from the set comprising spinning reel games, card games and ball games.  
     
     
         153 . The gaming system as claimed in  claim 150 ,  151  or  152 , wherein the predetermined triggering event is an event occurring in the current instance of the game.  
     
     
         154 . The gaming system as claimed in any one of claims  150 ,  151 ,  152  or  153 , wherein the predetermined triggering event is independent of the predetermined prize altering event.  
     
     
         155 . The gaming system as claimed in any one of claims  150 ,  151 ,  152  or  153 , wherein the predetermined triggering event is related to the predetermined prize altering event.  
     
     
         156 . The gaming system as claimed in  claim 155 , wherein there are a plurality of possible predetermined prize altering events and the predetermined triggering event is one of events that constitute the possible predetermined prize altering events.  
     
     
         157 . The gaming system as claimed in  claim 156 , wherein there are a plurality of possible triggering events which constitute a subset of the possible predetermined prize altering events.  
     
     
         158 . The gaming system as claimed in  claim 157 , wherein each predetermined prize altering event is a predetermined triggering event of the current instance of the game.  
     
     
         159 . The gaming system as claimed in any one of  claims 150  to  158 , wherein the predetermined prize altering event or events, are events independent of the current instance of the game.  
     
     
         160 . The gaming system as claimed in  claim 159 , wherein the predetermined prize altering event or events are related to the placing of a bet in respect of the current instance of the game.  
     
     
         161 . The gaming system as claimed in  claim 159  or  160 , wherein the predetermined prize altering event or events are otherwise non-winning events.  
     
     
         162 . The gaming system as claimed in any one of  claims 150  to  161 , wherein the predetermined triggering event is a random event.