Background of the Invention Niany schemes have been devised in the past to induce players to play slot machines including schemes such as specifying periods during which jackpot prizes are increased or bonus jackpots paid. Other schemes involve awarding an additional prize to a first player to achieve a predetermined combination oil a poker machine. These methods. while effective. add to club overheads because of the need for additional staff to ensure that the scheme is operated smoothly.

hlore recently. with the advent of poker machines linked through electrical networks it has been possible to automafically generate jackpot prizes on the basis of information received from the machines being played which are connected to the system and one such prior art arrangement, commonly known as "CashcadeT5"'. counts turnover on all machines in the network. increments a prize value in accordance with the turnover and pays the jackpot prize when the count reaches some predetermined and randomly selected number. In a more recent prior art arrangement. each game played on each machine in a gaming system is allocated a randomly selected number and the prize is awarded to a machine when the game number it is allocated matches a preselected random number.

In another recent prior art arrangement, the winning machine is selected by randomly selecting a number at a point in time and decrementing the number as games played on the system are counted until the number is decremented to zero at which time the game (or associated machine) causing the final decrement is awarded the jackpot.

With sone prior art combination based trigger arrangements there is a serious disadvantage in that the player betting a single token per line, is just as likely to achieve a jackpot as the player playing multiple tokens per line.

This has the effect of encouraging players playing for the bonus jackpot to bet in single tokens. rather than betting multiple tokens per game.

Jackpot games have traditionally been popular in Casinos. However, in their conventional format these games have inherent limitations: (i) Games which use specific combinations of symbols to trigger jackpots are perceived by many players as being unwinnable. The games are typically designed in such a way that the big jackpots should not be won until large amounts are accumulated. With such low frequency the jackpots are never seen to be won by most players. Anecdotal evidence suggests that many players have learnt to disregard the chance of winning the major jackpots and are realistically playing for the lesser jackpots (ie the minor and mini jackpots). The increasing popularity of small mystery jackpots with higher frequencies of occurrence tends to support this argument; (ii) Due to the increasing demand of players for a more complex and diverse game range, conventional jackpot games with combination triggers have become superseded. However, it is extremely complex to develop a wide variety of combinations which support both a feature game and mathematically exact jackpot triggers; (iii) Typically, it would be expected that the game return (RTP) is independent of the number of coins bet per line. With conventional progressive jackpot games though, increasing the credits bet per line creates a relative disadvantage as far as RTP is concerned. Lets say the start-up amount for a feature jackpot is $10000. A player who is playing 1 credit per line has a chance for $10000 for each credit played, whereas a player playing 5 credits per line only has a chance for $2000 for each credit played. This creates a scale of diminishing returns. The smart player who gambles for the feature jackpot only, will always cover all playlines, but will only bet 1 credit per line because the prize paid for the feature jackpot is the same irrespective of the bet. This is supported by data collected from casinos, (iv) Typical combination triggered progressive jackpots have fixed hit rates which removes from the operator's control the ability to vary jackpot frequency.

These arrangements have been in use in the State of New South Wales and in other jurisdictions for a considerable period of time, however, as with other aspects of slot machine games, players become bored with such arrangements and new and more innovative schemes become necessary in order to stimulate player interest.

In this specification. the term "combinations" will be used to refer to the mathematical definition of a particular game. That is to say. the combinations of a game are the probabilities of each possible outcome for that game.

Summarv of the Invention According to a first aspect the present invention provides a random prize awarding system associated with a gaming console. the console being arranged to a offer a feature outcome when a game has achieved a trigger condition. the console including trigger means arranged to test for a trigger condition and to initiate the feature outcome when the trigger condition occurs. the trigger condition being determined by an event having a probability related to credits bet per game on the console.

Accoidiiig to a second aspect. the present invention provides a random prize awarding strsteni associated with a network of gaming consoles. the system being arranged to offer a feature outcome on a particular console when a trigger condition occurs as a result of a game being played on the respective console the prize awarding system including trigger means arranged to test for a trigger condition and to initiate the feature outcome on the respective console when the trigger condition occurs. the trigger condition being determined by an event having a probability related to credits bet per game on the respective console.

According to a third aspect. the present iiwention provides a gaming console including a random prize awarding feature. the gaming console being arranged to offer a feature outcome when a game has achieved a trigger condition. the console including trigger meals arranged to test for the trigger condition and to initiate the feature outcome when the trigger condition occurs. the trigger condition being determined by an event having a probability related to credits bet per game on the console.

According to a fourth aspect, the present inventioii provides a method of awarding a random prize associated with a gaming console arranged to offer a feature outcome when a game has achieved a trigger condition, the method including testing for a trigger condition and initiating the feature outcome when the trigger condition occurs. the trigger condition being determined by an event having a probability related to credits bet per game on the respective console.

Preferably, the trigger condition is determined by an event having a probability related both to expected turnover between consecutive occurrences of the trigger condition, on the respective console and the credits bet on the respective game.

In a preferred embodiment of the invention. the trigger condition is determined by selecting a random number from a predetermined range of numbers to be associated with each bought game. and for each credit bet on the respective game. allotting to the game, one or more numbers from the predetermined range of numbers. and in the event that one of the numbers allotted to the player matches the randomly selected number. indicating that the trigger condition has occurred.

In one embodiment. one or more gaming consoles are connected in a gamillg network. each of the consoles including signal output means arranged to produce an output signal in response to operation of the respective console. such that a central feature jackpot system connected to the network provides an increnienting jackpot which is increased in response to signals froni the consoles connected to the network.

Preferably also. the console is arranged to play a first main game and the feature outcome initiated by the trigger condition is a second feature game.

The functioii of triggering a feature jackpot game may either be performed by a central feature game controller or mav be perfornied within each console in the system.

In the preferred embodiment. the predeterinined range of numbers is determined as a function of expected turnover between consecutive occurrences of the trigger condition. expected jackpot amounts and jackpot frequencies and will equal the expected average turnover per machine between successive initiations of progressive jackpot games divided by the credit value for that machine. For example. if the progressive jackpot is to be played for an average every $5,000 of turnover played and the credit value on the machine is $0.05, then the number range will be 1 to 100.000 (i.e.

5,000/0.05). In the preferred embodiment, the gaming machine will allocate the lowest numbers in the range to the player such that if the player plays 20 credits he will be allocated numbers 1-20 giving him a 1 in 5.000 chance of triggering a jackpot feature game.

Alternatively, the number range can be set to the average expected turnover between jackpot occurrences expressed in cents (500.000 in the above example). in which case the numbers allocated to the player, will be proportional to his total wager expressed in cents (i.e. 1-100 in the above example).

Preferably. the feature game is a simplified game having a higher probability of success than the first game. In a particularly preferred embodiment. the second game is a spinning reel game having a reduced number of symbols on each reel and a jackpot is activated if after spinning the reels a predetermined combination of symbols appears on the win line of each reel.

In one particular example. the second screen eagle is a five reel game with two different syiiibols oii each reel. Tlie symbols Illay be of equal value and equallv lveiglltecl (i.e. same number of installces) on each reel or alternatively. the prizes niight be of different values (eg: different fractions of the pool) and the symbols have different veightings on at least one reel.

Preferablv. the prize awarded in a jackpot game by the system of the present invention. is a nionetary amount the value of which is incremented with each game played on each gaming machine or console in the system.

Alternatively. the iicrenientation can take place on a per token bet basis.

Where used above. tlie term console' is used to indicate a gaming machine. a gaming terminal or other device arraiiged to be connected to a communications system and to provide a user gaming interface. In the following description. examples are give which are applicable to traditional slot machines. however the invention should be taken to include gaming systems which include user interfaces other than traditional slot machines.

Brief Description of the Drawings Embodiments of the invention will now be described by way of example, with reference to the accompanying drawings. in which: Figure 1 is a block diagram of a network of electronic gaming machines to which a mystery jackpot controller according to the present invention is connected: Figure 2 is a flow chart showing a game arrangement according to the invention: and Figure 3 shows an example of a 5 reel by 3 row window display.

Detailed Description of the Preferred Embodiments In a preferred embodiment of the invention. a new jackpot trigger mechanism provides the Casino operator with a far higher degree of flexibility. Unlike conventional combination triggered jackpots. the jackpots here are won front a feature game. The feature game is triggered randomly as a function of credits bet per game. When a feature is triggered. a feature game appears. Each jackpot can only be won from this feature game. During the feature game a second set of reel strips appears and a "spin and hold" feature game commences. The feature prize score is calculated by the total of the points appeariilg on the centre line of all 5 reels.

Feature jackpots ill this format exhibit significant differences over previous jackpot svstems: (i) Å jackpot galne is provided which is coiripatible with any existing game combillatioll lviti all lstallation independent of the platform.

denomination or type of ganie (eg. slot niachines. cards. keno. bingo or pachinko). This will allow for the linking of conibinations between game type. platform type and denomination. Using this system. jackpot games can now be developed using specific combinations for the base game which were previously unsuitable for Link Progressive Systems. These gamines will compete lvith the appeal of the latest ganies on tlie Illarket.

(ii) There is no longer a need to develop iiiatlieniatically exact combinations in the base game.

(iii) Unlike the multiplier game in conibiiiation triggered jackpot embodiments. the present invention provides a direct relationship between the number of credits bet and the probability of winnilig the jackpot feature game on any one bought game. Betting 10 credits per line will produce ten times as many hits into the feature game than betting 1 credit per line. This is achieved by using a jackpot trigger which is directly related to the wager bet on a respective game and the turnover. instead of using conventional combination triggers.

(iv) Jackpot hit rates can now be changed without making changes to the base game. This was previously not possible using combination triggered jackpots.

(v) The jackpot feature system can be used across a wide-area- network (WAN), local-area-network (LAN), used as a stand-alone game

independent of a network or used with a mystery jackpot. Flexibility is available to change combinations at will.

Referring to Figure 1 a plurality of electronic gaming consoles 10 are connected to a network 11. to which a feature jackpot controller 12 and display means 13 are also connected.

Each of the electronic gaming consoles 10 are provided with a network interface arranged to provide a signal onto the network 11 on each occurrence of an operation of a respective console and the jackpot controller 12 is arranged to receive each of the console operation signals and to increment the value of a random jackpot prize on the occurrence of each of these operation signals.

A How chart for a prize awarding algorithm is illustrated in Figure 2.

Referring to tlie algorithm of Figure 2. machine contributions go into the prize pool as with known prior art jackpot systems. l,n7hile the overhead display shows the incrementing prize value.

In the EGNI. an average value of machine turnover between jackpot hits. is programmed and is used to randomly generate trigger data for the jackpot feature games. In step 20 of the algorithm of Figure 2. the actual number range and therefore probability of a feature jackpot ganie being awarded will depend upon the value of a credit ill the particular machine and is calculated bv dividing the turnover value by the value of a credit (eg..

$5000/$0.05 = 100.000). The average turnover value is fixed for the EGNts and the randomly number generator is initialised (see step 20) at startup to generate nulllbers from the preprograninied range deterniined from that value.

For every game that is played. a random trigger value is selected (see step 21) in the preprogrammed range as determined from the average turnover value. When the game is commenced. it is then reported (see step 22) to the controller. which allocates a contribution to the prize pool. Each game is also allotted (see step 23) numbers from the same number range that from which the random number was selected, one number in the range being allotted for each credit bet such that the players probability of being awarded a jackpot feature game is proportional to the bet.

The previously selected random number is then used as a trigger value and compared with the values allotted to the player, if there is a match (see step 24) between the trigger value and the player values. the player is given

an opportunity to play a jackpot feature game (see step 25). Alternatively, at step 23 a number is allocated which is equal to. or proportional to the number of credits bet in the respective game and in step 24. the trigger value is compared with the single player value and a jackpot feature awarded if the trigger value is less than or equal to the player value. It will be appreciated that this alternative arrangement is mathematically equivalent to the previously described arrangement, the range of numbers below the allotted number in the alternative arrangement being equivalent to the set of allotted numbers in the previously described arrangement.

In the preferred embodiment, a prize is always awarded in the jackpot feature game. the feature game being used to determine the size of the prize to be awarded (see step 27). The winning machine is then locked up (see step 28) and the controller awaits an indication that the prize has been paid before allowing the riiachine to be unlocked (see step 29). In some embodiments. the machine will not be locked up in steps 28 and 19. but instead the prize will simplv be paid and the program will return to step 21.

The machine then returns to step (see step 21) and commences a new game.

If the trigger value does not match (see step 27) then there is no feature game awarded for that bought game and the machine returns to step (see step 22) and waits for the next game to commence.

Bv way of example. a feature game night be triggered bv an EGNI every $5000 of turnover played. which is equivalent to 100.000 credits on a $0.05 machine. This is referred to as the jackpot feature ganie hit rate in credits. A random number is generated within a prescribed range of numbers at the EGNI at the commencement of each bought ganle. The prescribed range of numbers is determined by the jackpot feature game hit rate which has been determined previously, from typical values of casino turnover. expected jackpot amounts and jackpot frequencies. The prescribed range in this example is therefore 1 to 100.000 and before the commencement of each bought game a random number is generated within this range.

A bet of 20 credits will result in the numbers between 1 and 20 (inclusive) being allotted to the game (note that statistically it does not matter if the numbers are randomly selected or not or allotted as a block or scattered. the probability of a feature game being awarded is unchanged). If the number 7 is produced by the random number generator. then the feature game will be triggered. If any number between 21 and 100.on0 is produced by the random number generator. the feature game will not be triggered.

Similarly, a bet of 200 credits will result in the numbers between 1 and 200 (inclusive) being allotted to the game. If any number between 1 and 200 is produced bv the random number generator. then the feature game will be triggered. If any number between 201 and 100.000 is produced bv the random number generator. the feature game will not be triggered.

The example below has been developed using example turnover data.

A trigger of the second screen feature game is expected every $5000 of turnover (ie. 100000 credits oil a $0.05 machine). Increasing the number of credits bet increases the chance of triggering the feature oil any bought game. Number of Range numbers Games to hit Bet/game Turnover of EGNI since last hit credits bet assined i (S) 1 1 to 1 100000 $0.05 $5000 2 1 two 2 50000 $0.10 $5000 3 1 to 3 ~ 33333.33 $0.15 $5000 5 1 to 5 20000 $0.25 $5000 10 1 to 10 10000 1 $0.50 $5000 15 ~ 1 to 15 6666.66 $0.75 $5000 20 1 to 20 5000 $1.00 $5000 25 1 to 25 4000 $1.25 $5000 30 1 to 30 3333.33 $1.50 $5000 40 1 to 40 2500 $2.00 $5000 45 1 to 45 2222.22 $2.25 $5000 50 1 to 50 2000 $2.50 $5000 60 1 to 60 1666.66 $3.00 $5000 75 1 to 75 1333.33 $3.75 $5000 100 1 to 100 1000 $5.00 $5000 150 1 to 150 666.66 $7.50 $5000 200 1 to 200 500 $10.00 $5000 Preferably, when a jackpot feature game is triggered. all players are alerted by a jackpot bell that a possible grand jackpot is about to be played for. This is done so that all players share in the experience of a jackpot win.

Anecdotal evidence of players watching feature gangs being played in

Australian casinos suggests that the drawing power of such games is immense.

Plavers are alerted bv the jackpot bell instantaneouslv at any point during a game. but the feature game will not appear until the current game (including base ganie features) are completed.

In this embodiment the feature game appears with the new reel strips already spinnilig and accompanying feature game tunes playing. The player stops the reels spinnilig bv pressing the corresponding playline buttons in order. The feature prize score is calculated by the total of the points appearing oil the centre line of all 5 reels. Across the top of the screen. a sum of the scores is displayed.

The 4 feature prize nletels in descending order of value are: (i) Grand Feattlrc Prize. A score of # 100 wins the grand feature jackpot: (ii) Major Feature Plize.. A score of 90-99 (inclusive) wins the major feature jackpot: (iii) Nlinor Feature Prize. A score of 80-89 (inclusive) wins the minor feature jackpot: (iv) Nliiii Feature Prize. A score of #79 wins the mini feature jackpot.

Bv way of exaiiiple. referring to Figure 3. a 5 reel bv 3 row window is displayed. If the reels of the feature game stop Oil the numbers shown in Figure 3. then the progressive jackpot won is the suni of the nunlbers on the centre line ie. 12+10+18+13+22 = 75 which is within the range for the mini feature jackpot.

The instant the feature game is completed and the sum of scores from all 5 reels is shown. the feature jackpot screeii and signs display which jackpot has been won. This celebration of the jackpot win is conducted in a traditional manner (i.e. flashing displays. jackpot alarms. music etc).

As the time between jackpot game awards is related to turnover, the number of jackpot games played by a player between feature games and hence their chance of winning is directlv related to the size of each bet on each game played.

(1) All machines on the link have a feature game. be it a second screen animation game or a second set of reel strips.

(2) The link has a number of feature jackpot meters (up to 8). All feature jackpots may be linked.

(3) The feature game is activated as a function of machine turnover. This means that on average the feature game will occur one in. for example every $5000.00. There are a number of advantages of activating the feature game on turnover. For example it enables for the first time. a relatively simple mechanism for allowing mixed denomination on a link. The feature game gives the player the chance of winning one of the available feature jackpots if a certain outcome appears. For example. a new set of reel strips might appear with only 2 or 4 different symbols: Jackpot 1. Jackpot 2. or (Jackpot 1.

Jackpot 2. Jackpot 3. Jackpot 4). The first time 5 of the same appear on the centre line the stated feature jackpot is won.

(4) Another advantage of using a random trigger for a feature game. is that it can be applied to any game It will be appreciated by persons skilled in the art that numerous variations and/ol modifications may be made to the invention as shown in the specific embodiments vithout departing from the spirit or scope of the invention as broadlv described. The present embodiments are. therefore. to be considered in all respects as illustrative and not restrictive.