Abstract:
Disclosed herein is a game played on a gaming device that displays a randomly selected array of symbols, where the symbols across one or more pay lines are evaluated by circuitry to determine an award to be granted. In one embodiment, the gaming device allows the player to designate a position in the array for a next spin of the virtual reels. After the next spin, the symbol in that designated position becomes a scatter symbol. A scatter symbol is a symbol whose significance applies whether it occurs on a certain pay line or not. A certain number of scatter symbols in the array causes an award to be granted to the player. The scatter symbols may have other special award features, such as a providing an award multiplier or initiating a bonus game.

Description:
FIELD OF THE INVENTION 
     This invention relates to gaming devices, such as slot machines, and, in particular, to an additional feature performed in a game that grants awards to a player based upon symbol combinations. 
     BACKGROUND 
     Common slot machines randomly select and display an array of symbols on a video screen, then grant an award to a player based on the occurrence of certain symbol combinations across pay lines. Typically, the game ends after the symbols are displayed and the award, if any, is granted. Although these types of games are highly successful, it is advantageous to provide an additional feature to this basic game to make the game more interesting to a player. A more interesting game will generate increased revenue to the casino by its increased play. 
     SUMMARY 
     Disclosed herein is a game played on a gaming device that displays a randomly selected array of symbols, such as a video slot machine or a video monitor connected to a computer for on-line gaming. In one embodiment, the array is 5×3 symbol positions. The combinations of symbols across one or more activated pay lines are evaluated by a processor to determine an award to be granted. The present invention adds an additional feature to this conventional operation of a gaming machine. 
     One embodiment of the present invention allows the player to designate a symbol position in the 5×3 array to have a special function for the next spin of the virtual reels. After the next spin, the symbol in that designated position becomes a scatter symbol. A scatter symbol is a symbol whose significance applies whether it occurs on an activated pay line or not. In one example, the spin resulted in the symbol “C” occurring in the selected position. All “Cs” in the array are then scatter symbols. In one embodiment, three scatter symbols (i.e., Cs) pay a first award, four scatter symbols pay a higher award, and five scatter symbols pay an even higher award. In another embodiment, the scatter symbols multiply an award based on the number of scatter symbols. Many other award features can apply to the scatter symbols. 
     In one embodiment, the player pays for the opportunity to designate one or more positions for the scatter symbols. In another embodiment, the opportunity for designating the one or more positions occurs as a bonus if the previous spin resulted in a certain winning combination of symbols. Alternatively, the opportunity may occur randomly or occur based on other criteria. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         FIG. 1  illustrates a gaming machine that may display a game in accordance with the present invention. 
         FIG. 2  is a block diagram of key components in the gaming machine of  FIG. 1 . 
         FIG. 3  illustrates a video screen displaying a 5×3 array of symbols and three pay lines, where one symbol position has been selected by the player for a scatter symbol in the next spin. 
         FIG. 4  is a flowchart illustrating one embodiment of the inventive method. 
         FIG. 5  illustrates the video screen image for the next spin, where the selection of the symbol position in  FIG. 3  resulted in the symbol “C” being a scatter symbol. 
     
    
    
     DETAILED DESCRIPTION 
     Although the invention can typically be implemented by installing a software program in most types of modern video gaming machines, one particular gaming machine platform will be described in detail. 
       FIG. 1  is a perspective view of a gaming machine  10  that incorporates the present invention. Machine  10  includes a display  12  that may be a thin film transistor (TFT) display, a liquid crystal display (LCD), a cathode ray tube (CRT), or any other type of display. In the preferred embodiment, display  12  has a touch screen feature that enables the player to make selections, such as selecting a symbol position in a displayed array, by touching the symbol position. 
     A second display  14  provides game data or other information in addition to display  12 . Display  14  may provide static information, such as an advertisement for the game, the rules of the game, pay tables, pay lines, or other information, or may even display the game itself along with display  12 . Alternatively, the area for display  14  may be a display glass for conveying information about the game. 
     A coin slot  22  accepts coins or tokens in one or more denominations to generate credits within machine  10  for playing games. An input slot  24  for an optical reader and printer receives machine readable printed tickets and outputs printed tickets for use in cashless gaming. A bill acceptor  26  accepts various denominations of banknotes. 
     A coin tray  32  receives coins or tokens from a hopper upon a win or upon the player cashing out. 
     A card reader slot  34  accepts any of various types of cards, such as smart cards, magnetic strip cards, or other types of cards conveying machine readable information. The card reader reads the inserted card for player and credit information for cashless gaming. The card reader may also include an optical reader and printer for reading and printing coded barcodes and other information on a paper ticket. 
     A keypad  36  accepts player input, such as a personal identification number (PIN) or any other player information. A display  38  above keypad  36  displays a menu for instructions and other information and provides visual feedback of the keys pressed. 
     Player control buttons  40  include any buttons needed for the play of the particular game or games offered by machine  10  including, for example, a bet button, a repeat bet button, a spin reels button, a maximum bet button, a cash-out button, a display pay lines button, a display payout tables button, select icon buttons, and any other suitable button. Buttons  40  may be replaced by a touch screen with virtual buttons. 
       FIG. 2  illustrates basic circuit blocks in a suitable gaming device. A control unit (CPU  42 ) runs a gaming program (including the invention) stored in a program ROM  48 . The program ROM  48  may include a pseudo-random number generator program for selecting symbols and for making other random selections. A coin/credit detector  44  enables the CPU  42  to initiate a next game. A pay table ROM  50  detects the outcome of the game and identifies awards to be paid to the player. A payout device  46  pays out an award to the player in the form of coins upon termination of the game or upon the player cashing out. The payout may also be in the form of a coded paper ticket, credits on a smart card or magnetic strip card, or in any other form. A display controller  52  receives commands from the CPU  42  and generates signals for the various displays  54 . If a display  54  is a touch screen, player commands may be input through the display screen into the CPU  42 . 
     The invention may be carried out on any form of video game that determines an award based upon combinations of symbols across one or more pay lines. There may be an array of 3×3 symbols, an array of 5×3 symbols, or any other arrangement of symbols. A 5×3 array of symbols will be used as an example, and such an array  57  is shown in  FIG. 3 , where each symbol position  58  displays a randomly selected symbol, such as letters A-O. 
     Any pattern of pay lines through the array  57  may be utilized, such as straight or zig-zag pay lines. Three pay lines  60  are illustrated in  FIG. 3  for simplicity. Typically, the player bets additional credits to activate more than the center pay line (e.g., one additional pay line per credit bet). In a conventional game, only symbols along an activated pay line are used in forming winning combinations of symbols for paying an award. 
     Standard symbols include fruit symbols and symbols associated with the theme of the particular slot machine. The particular icons used are not important. Typically, a code associated with each possible symbol is stored in memory, and a pseudo-random number generator selects the symbol to be displayed on the video screen. For amusement, each vertical column of symbols is scrolled to emulate a motor-driven reel, and each of the virtual reels is typically stopped in sequence after a few seconds to reveal the final 5×3 array of symbols. 
     The invention will be described in conjunction with the screens of  FIGS. 3 and 5  and the flowchart of  FIG. 4 . 
     In step  64  of  FIG. 4 , the player bets credits and spins the virtual reels in a conventional manner. The reels are stopped to display a random array of symbols, shown in  FIG. 3 , typically selected by a pseudo-random number generator. 
     In step  66 , it is determined whether the condition is met for enabling a scatter symbol feature. Such a condition may be met by the player betting one or more additional credits, by the player betting the maximum credits, by the player obtaining a certain combination of symbols, by a random initiation of the feature, by a predetermined intermittent initiation of the feature, or by any other condition or combination of the above conditions. In one embodiment, the player always gets the feature after each spin, where the condition is simply that the previous spin has been completed. 
     In step  68 , if the condition is met, the player selects one symbol position by touching that position on the display screen. In some circumstances, the player may be given the option of selecting more than one symbol position, such as if the player bet additional credits or obtained a special symbol combination. Only one position is selected in the example for simplicity. In this example, the player chose the middle position on the rightmost reel. That selected symbol position is highlighted such as by displaying a circle  70  in that symbol position. 
     In step  72 , the reels are again spun by the player. The player may be required to bet one or more credits for the spin or the spin may be a free spin as a bonus for a particular symbol combination.  FIG. 5  shows the display after the reels have been randomly stopped. 
     Since the symbol “C” is displayed in the position previously selected by the player (middle position of rightmost reel), that C symbol becomes a scatter symbol, and all other C symbols in the array also become scatter symbols (step  74 ). The key characteristic of a scatter symbol is that it does not have to be on the same pay line with other scatter symbols for it to be combined with the other scatter symbols to generate an award. Scatter symbols anywhere in the array may be combined or otherwise used to create a winning combination. In some embodiments, scatter symbols may even be combined with non-scatter symbols to generate an award. In one embodiment, a first award is granted for three of the same scatter symbols, a higher award is granted for four of the same scatter symbols, and an even higher award (such as a jackpot) is granted for five of the same scatter symbols. 
     As shown in the example of  FIG. 5 , a total of five scatter symbols are displayed. The scatter symbols may be highlighted such as with a circle. In one embodiment, only scatter symbols in different columns may be combined with other scatter symbols. 
     The scatter symbols may also award special prizes, such as free games, a special bonus game, or other awards. The scatter symbols may act as a wild card for any position on its reel. 
     In another embodiment, the number of scatter symbols determines a multiplier for any other award obtained by the combination of symbols in either the current spin, the previous spin, or the next spin. 
     The machine may pay out all the wins from the combinations of the symbols or just the highest win amount. 
     In one embodiment, the scatter symbol feature applies only to a single spin. In other embodiments, the player may spin multiple times with the same selected scatter symbol position. 
     In one mode of operation, the number of positions available for selection for a scatter symbol may increase from spin to spin under certain circumstances, such as the player obtaining certain symbol combinations in each spin. Each selected position may identify a different scatter symbol during the next spin so that multiple symbols will be scatter symbols in the next spin. All scatter symbols may have the same value or some scatter symbols may have different functions (e.g., multipliers vs. credits). 
     In another embodiment, the gaming machine automatically picks one or more scatter symbol positions for the player in step  68 . 
     While particular embodiments of the present invention have been shown and described, it will be obvious to those skilled in the art that changes and modifications may be made without departing from this invention in its broader aspects and, therefore, the appended claims are to encompass within their scope all such changes and modifications as fall within the true spirit and scope of this invention.