Patent Publication Number: US-2002010017-A1

Title: Gaming machine with a free game, single reel spin feature

Description:
FIELD OF THE INVENTION  
       [0001] This invention relates to a gaming machine. More particularly, the invention relates to a gaming machine and to an improvement to a game played on such a gaming machine.  
       BACKGROUND TO THE INVENTION  
       [0002] Players who regularly play gaming machines, quickly tire of particular games and therefore it is necessary for manufacturers of these machines to develop innovative game features which add interest to the games. In so doing, it is hoped to keep players amused and therefore willing to continue playing the games as well as to attract new players.  
       [0003] Also, with the growth that has occurred in the gaming machine market, there is intense competition between manufacturers to supply various existing and new venues. When selecting a supplier of gaming machines, the operator of a venue will often pay close attention to the popularity of various games with their patrons. Therefore, gaming machine manufacturers are keen to devise games which are popular with the players as a mechanism for improving sales, retaining customers and attracting new customers.  
       SUMMARY OF THE INVENTION  
       [0004] According to the invention, there is provided a gaming machine having a display means and a game control means arranged to control images displayed on the display means, the game control means being arranged to play a game wherein at least one random event is caused to be displayed on the display means and, if a predefined winning event results, the machine awards a prize, the gaming machine being characterised in that, upon completion of a base game which includes a trigger condition, a feature game sequence is initiated wherein, in respect of at least certain of the games of the feature game sequence, at least one of a plurality of image carrying elements from a preceding game is held, a decision as to which image carrying element is to be held being made independently of the trigger condition, while remaining image carrying elements displayed on the display means are caused to change.  
       [0005] The invention is intended particularly for use in spinning reel-type games where each image carrying element is a video simulation of a spinning reel. Those skilled in the art will appreciate that the video simulations of spinning reels carry a number of symbols thereon which, when the reels stop spinning cause a plurality of the symbols to be displayed on the display means. It will. however, be appreciated that the invention could be applicable to other types of games, for example, card games, ball games, such as Keno. or the like.  
       [0006] The feature game sequence may be a series of free games. The trigger condition may be any suitable trigger condition, such as, for example, the presence of a number of scatter symbols on the display means.  
       [0007] In the series of free games, the first game of the series of free games may have all its image carrying elements changed to refresh the display, ie. all the reels may be re-spun. For remaining games of the series of free games, only one of the image carrying elements is caused to change each time, ie. only one of the reels may be re-spun in each free game of the series. The reel which is selected for re-spinning may be randomly selected by the game control means and may differ from one game to the next in the series of free games.  
       [0008] If another trigger condition occurs during the series of free games, a new series of free games may be started. The new series of free games may be added to the series of free games remaining from an initial sequence of free games. In other words, in the example as specified above, if the plurality of scatter symbols again appears, a new series of free games is started.  
       [0009] In one embodiment of the invention, in the first free game of the new series, all the reels may be re-spun whereafter only one of the reels in the free games is re-spun for each free game. Instead, in a first game of the new series of free games, only one of the image carrying elements may be caused to change by the control means rather than the entire screen display being refreshed.  
       [0010] Any wins which occur during the feature game sequence may pay a predetermined integer multiple of that which an equivalent win pays in the base game. Typically, any win in one of the feature games may pay triple that of the equivalent win in the underlying base game.  
       BRIEF DESCRIPTION OF THE DRAWINGS  
       [0011] The invention is now described by way of example with reference to the accompanying diagrammatic drawings in which:  
       [0012]FIG. 1 shows a three dimensional view of a gaining machine, in accordance with the invention;  
       [0013]FIG. 2 shows a schematic block diagram of a control circuit of the gaming machine of FIG. 1;  
       [0014]FIG. 3 shows an example of a screen display of a result of a base game played on the gaming machine of FIG. 1;  
       [0015]FIGS. 4 a  to  4   e  show various screen displays of a feature game sequence of the game:  
       [0016]FIG. 5 shows a flow chart of the game of FIGS. 3 and 4 a  to  4   e;  and  
       [0017]FIG. 6 shows a flow chart of another embodiment of the game of FIGS. 3 and 4 a  to  4   c.   
     
    
    
     DETAILED DESCRIPTION OF THE DRAWINGS  
     [0018] In FIG. 1, reference numeral  10  generally designates a gaming machine, including a game, in accordance with the invention. The machine  10  includes a console  12  having a video display unit  14  on which a game  16  is played, in use. The game  16  is a spinning reel game which simulates the rotation of a number of spinning reels  18 . A midtrim  20  of the machine  10  houses a bank  22  of buttons for enabling a player to play the game  16 . The midtrim  20  also houses a credit input mechanism  24  including a coin input chute  24 . 1  and a bill collector  24 . 2 .  
     [0019] The machine  10  includes a top box  26  on which artwork  28  is carried. The artwork  28  includes paytables, details of bonus awards, etc.  
     [0020] A coin tray  30  is mounted beneath the console  12  for cash payouts from the machine  10 .  
     [0021] Referring now to FIG. 2 of the drawings, a control means or control circuit  32  is illustrated. A program which implements the game and user interface is run on a processor  34  of the control circuit  32 . The processor  34  forms part of a controller  36  which drives the screen of the video display unit  14  and which receives input signals from sensors  38 . The sensors  38  include sensors associated with the bank  22  of buttons and touch sensors mounted in the screen. The controller  36  also receives input pulses from the mechanism  24  indicating that a player has provided sufficient credit to commence playing. The mechanism  24  may, instead of the coin input chute  24 . 1  or the bill collector  24 . 2 , or in addition thereto, be a credit card reader (not shown) or any other type of validation device.  
     [0022] Finally. the controller  44  drives a payout mechanism  40  which, for example, may be a coin hopper for feeding coins to the coin tray  30  to make a pay out to a player when the player wishes to redeem his or her credit.  
     [0023] Referring now to FIG. 3 of the drawings, the result of a base game  16  is shown. In this example, three scatter symbols S  42  are spun up. The presence of the three scatter symbols  42  is a trigger condition which starts a feature sequence being a predetermined number of free games such as sixteen free games. In addition, a win is paid for the three scatter symbols  42 .  
     [0024] In a first game of the series of free games, the screen display of which is shown at  44  in FIG. 4 a  of the drawings, all five reels  18  are re-spun. In the example shown in FIG. 4 a  a win is paid for five Jacks on line one. There are now fifteen free games remaining.  
     [0025] After the second free game, the result is as shown in FIG. 4 b  of the drawings. Only the fourth reel has been selected to be re-spun, the selection taking place randomly under the control of the control circuit  32  of the machine  10 . the remaining reels  18  having been held. In this regard, it is to be noted that the control circuit  32  makes the decision as to which reels  18  are to be held in each free game of the series independently of which reels  18  carried the scatter symbols  42  which triggered the feature sequence. In the game shown in FIG. 4 b,  a win is paid for three Jacks on the first payline. Fourteen games remain of the series of free games.  
     [0026] After the third spin, the result is as shown in FIG. 4 c  of the drawings. In this case, the second reel  18  has been selected by the control circuit  32  to be re-spun with the remaining reels  18  being held. Once again, three scatter symbols  42  are present so that the feature sequence, i.e. the series of free games or spins, re-occurs. In other words, the presence of the three scatter symbols  42  triggers a new series of free games so that there are now twenty-nine free games being the thirteen remaining games from the initial series of free games plus the sixteen of the second series of free games. A prize is also paid for the three scatter symbols  42 .  
     [0027] In a first embodiment of the invention, in a first game after the second trigger condition, ie. the first game of the remaining twenty-nine games, the control circuit  32  only selects one reel  18  to be re-spun with the remaining reels  18  being held. Instead, in a second embodiment of the invention, the presence of the three scatter symbols  42  re-triggers the feature and all the reels  18  are re-spun for the first game in the new series of free games with the result being shown in FIG. 4 d  of the drawings. For this game, a win is paid for three Kings on payline two as well as four Tens on payline three. There are now twenty-eight free games remaining.  
     [0028] For the following game in the second embodiment of the invention, only one of the reels  18  is re-spun. Once again, the fourth reel  18  is randomly selected to be re-spun and the result is shown in FIG. 4 e  of the drawings. A prize is paid for four Kings on payline two and for three Tens on payline three. There are now twenty-seven free games or spins remaining which take place as described above.  
     [0029] In respect of either embodiment described above, any wins which occur during a free game of the feature pay a predetermined multiple of that which the equivalent win pays in the underlying base game. Typically, any win in one of the feature games pays triple that of the equivalent win in the underlying base game.  
     [0030] It is an advantage of the invention that a feature game sequence is provided which the applicant believes will enhance player interest.  
     [0031] It will be appreciated by persons skilled in the art that numerous variations and/or modifications may be made to the invention as shown in the specific embodiments without departing from the spirit or scope of the invention as broadly described. The present embodiments are, therefore, to be considered in all respects as illustrative and not restrictive.