GAMING MACHINE AND METHOD FOR DISPLAYING SYMBOLS

Abstract

A gaming machine comprises a display unit that displays video reels using computer graphics. Symbols are moved and stopped on each video reel. A game controller unit selects a type of symbols and an arrangement of symbols at random, and provides a player with an award if a winning combination appears on a payline in the arrangement of symbols and the player has placed a bet on the payline. A display controller unit causes the display unit to move symbols on each video reel, and then stop symbols in the arrangement. The display controller unit further causes the display unit to change a symbol of the selected type to a special symbol while moving symbols. Special symbols appear in a prominent form, e.g., in a background color complementary to a background color of other symbols, or in a metallic color, or in a blinking, flashing, or sparkling pattern.

Description

BACKGROUND OF THE INVENTION

1. Field of the Invention

The present invention relates to a gaming machine that is installed in a casino or the like, and in particular conducts a slot game.

2. Background Information

Gaming machines such as slot machines, poker machines, fruit machines, and the like generally attract enormous popularity from players in casinos. Such a gaming machine displays an arrangement of symbols on the front thereof, and changes the types of symbols in the arrangement at random. A player guesses on which payline in the arrangement of symbols a winning combination will appear, and then places a bet on a desired payline before symbols are changed in the arrangement. If a winning combination appears on the payline where the player has placed a bet, the player will win an amount of a payout that depends on the amount of the bet and the type of the winning combination.

This type of gaming machine is generally equipped with mechanical reels that are coaxially arranged and allowed to independently spin by respective motors. Symbols are permanently displayed, e.g., printed on the circumferential surfaces on each reel in a predetermined order. Mechanical reels repeat spins and stops, and thereby change visible symbols at random. Alternatively, this type of gaming machine may be equipped with an electric display device, and symbols are arranged in graphic form, i.e., a video reel reproduced on a screen of the electric display device. Video reels are changed to look like mechanical reels repeating spins and stops, and thereby change visible symbols at random. There is also a mechanical reel with one or more electric display devices mounted on the circumferential surface of the mechanical reel. Symbols are displayed in graphic form on a screen of the electric display device.

Most players prefer a gaming machine that can provide a larger amount of payout. The upper limit of payout generally depends on a total number of winning combinations that can appear in an arrangement of symbols visible on reels. Mechanical reels have a limited number of symbol types mainly because of their sizes. In order to increase the upper limit of payout, a gaming machine with mechanical reels changes visual effects added to visible symbols in stopped positions, e.g., colors or pattern of illumination thereof in order to increase the number of symbol types. This can also excite a player by raising his/her expectations for winning. On the other hand, video reels have no limited number of symbol types in principle. However, video reels often change visual effects added to visible symbols in stopped positions in order to change types of the visible symbols and thereby raise players' expectations for winning. On video reels, graphic form of symbols can enhance flexibility and variety of the changes in visual effect, in addition to colors and pattern of illumination of visual symbols.

In order to attract a larger number of players to such gaming machines, it is desirable to be able to further enhance flexibility and variety of changes in visual effect added to visible symbols. However, prior art gaining machines limit changes in visual effects to visible symbols in stopped positions in order to produce the changes in a recognizable manner. However, the changes after stop of reels tend to increase an amount of time per game round. This prevents the changes from achieving higher degrees of flexibility and variety, since excessively longer time per game round is not attractive to players.

In view of the above, it will be apparent to those skilled in the art from this disclosure that there exists a need for an improved gaming machine that can change visual effects added to visible symbols, not only with higher degrees of flexibility and variety, but also in a manner more attractive to players. This invention addresses this need in the art as well as other needs, which will become apparent to those skilled in the art from this disclosure.

SUMMARY OF THE INVENTION

A gaming machine according to the present invention comprises a display unit, a console unit, a game controller unit, and a display controller unit. The display unit is configured to display symbols using computer graphics. The symbols are arranged in a plurality of columns, and moved and stopped on a column-by-column basis. Note that the display unit may display all symbol columns, i.e., video reels on a single screen, or alternatively each symbol column on a screen wound around the circumferential surface of a mechanical reel. The console unit is configured to accept monetary data and an instruction from a player to place a bet. The game controller unit is configured to execute a game program, and thereby control the following game functions: using the monetary data as a bet in response to the instruction; selecting a type of symbols at random; determining an arrangement of symbols at random; retrieving a winning combination from the arrangement of symbols; and providing the player with an award depending on the bet and the winning combination retrieved from the arrangement of the symbols. The display controller unit is configured to cause the display unit to move symbols on a column-by-column basis, and then stop symbols in the arrangement selected by the game controller unit. The display controller unit is further configured to cause the display unit to change a symbol of the type selected by the game controller unit to a special symbol while moving symbols.

This game machine selects a type of symbols at random, and changes symbols of the selected type to a special symbol while moving symbols. This not only increases a number of symbol types, thereby raising an upper limit of payouts, but also excites a player by raising his/her expectations for winning, while symbols are moved, preferably, during a spin of reels.

The game controller unit is preferably configured to interpret the special symbol as a wildcard symbol. In this case, changes of symbols of the selected type to the special symbol are actually advantageous to a player, since the player has a good chance of winning.

The display controller unit is preferably configured to cause the display unit to change a background color of the special symbol to a color complementary to a background color of other symbols while moving symbols. This can change symbols of the selected type to the special symbol in an easily recognizable manner. Alternatively, the display controller unit may be configured to cause the display unit to display only the special symbol in a metallic color while moving symbols. The display controller unit may be configured to cause the display unit to display the special symbol in a blinking, flashing, or sparkling pattern while moving symbols.

The display controller unit is preferably configured to provide a higher probability of displaying candidates for a type of symbols to be changed to a special symbol at adjacent positions while the display unit moves symbols, than other types of the symbols. In this case, there is a good chance that a group of special symbols appear in a visible position while symbols are moved. This can cause a player to more reliably notice the changes of the selected symbol to a special symbol.

The display unit preferably includes a region in which candidates for a type of symbols to be changed to a special symbol are displayed in a static graphic form. In this case, the display controller unit is preferably configured to cause the display unit to change the candidate of a type has been selected by the game controller unit to a special symbol in the region while the display unit moves symbols. A player can confirm an appearance and a type of a special symbol through the display in the region.

The game controller unit is preferably configured to select two or more types of symbols at random. In this case, the display controller unit is preferably configured to cause the display unit to change symbols of the types selected by the game controller unit to special symbols in turn while moving symbols. This visual effect can excite a player by gradually raising his/her expectation of winning while moving symbols.

These and other objects, features, aspects and advantages of the present invention will become apparent to those skilled in the art from the following detailed description, which, taken in conjunction with the annexed drawings, discloses a preferred embodiment of the present invention.

BRIEF DESCRIPTION OF THE DRAWINGS

Referring now to the attached drawings which form a portion of this original disclosure:

FIG. 1 is a perspective view of the appearance of a gaming machine according to an embodiment of the present invention;

FIG. 2 is a block diagram of the hardware configuration of a game controller unit included in the gaming machine shown in FIG. 1;

FIG. 3 is an example of a symbol arrangement in stopped positions displayed on a screen of the gaming machine shown in FIG. 1;

FIG. 4 is another example of a symbol arrangement in stopped positions displayed on a screen of the gaming machine shown in FIG. 1;

FIG. 5A is an example of a first state of moving symbols displayed on a screen of the gaming machine shown in FIG. 1;

FIG. 5B is an example of a second state of moving symbols displayed on a screen of the gaming machine shown in FIG. 1;

FIG. 5C is an example of a third state of moving symbols displayed on a screen of the gaming machine shown in FIG. 1;

FIG. 6A is a first half of a flow chart of a game round conducted on the gaming machine shown in FIG. 1; and

FIG. 6B is a second half of the flow chart of a game round conducted on the gaming machine shown in FIG. 1.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT

A selected embodiment of the present invention will now be explained with reference to the drawings. It will be apparent to those skilled in the art from this disclosure that the following description of the embodiment of the present invention is provided for illustration only and not for the purpose of limiting the invention as defined by the appended claims and their equivalents.

A preferred embodiment of the present invention is a video gaming machine preferably installed in a casino. Referring to FIG. 1, the gaming machine comprises a box-shaped cabinet 1 with an openable and closable front panel 2. Three display units 3A, 3B, and 3C are mounted on the upper portion, the middle portion, and the lower portion of the front panel 2, respectively. A coin slot 5, a bill slot 6, and various push buttons 8 are mounted between the middle display window 3B and the lower display window 3C. A coin chute 9, a coin tray 10, and a speaker 11 are installed below the lower display window 3C.

The three display units 3A, 3B, and 3C each include a flat display device preferably, or a liquid crystal display device more preferably. The display units 3A, 3B, and 3C reproduce various images, for example, images for use in decoration and advertisements, e.g., the logo of a game developer, images for use in visual effects in games, and visualized information on games, e.g., pay tables, illustrations of game content, and jackpot values. In particular, the middle display unit 3B displays preferably five video reels, i.e., five symbol columns, the number of available credits of a player, the amount of a bet, and the amount of an award that the player has won.

The coin slot 5 and the bill slot 6 allow a player to enter coins and bills thereinto, respectively. The entered coins and bills are counted by a counter and validated by an acceptor. The counter and the acceptor are installed inside the cabinet 1. The total amount of the validated coins and bills are displayed on the middle display unit 3B as credits available to the player. A coin hopper installed inside the cabinet 1 stores a large number of coins and bills together with the coins and bills entered by the player. The coin hopper discharges coins equivalent to credits that a player has won on a game through the coin chute 9 into the coin tray 10. Note that the gaming machine may support a ticket-in/ticket-out system, i.e., accept and print a bar-coded paper ticket. A bar code printed on the ticket represents monetary data available to a player.

The push buttons 8 allow a player to operate the gaming machine. For example, by using the push buttons 8, a player can select one or more paylines on the video reels, and place a desired amount of a bet on each selected payline. The player then pushes a spin button included in the push buttons 8 to cause the video reels to start spinning, i.e., symbols to move in the vertical direction. If an arrangement of stopped symbols includes a winning combination on any of the selected paylines, the player will win an award depending on the amount of the bet and the type of the winning combination. The player will be allowed to push a cash-out button included in the push buttons 8, and then receive coins equivalent to the player's credit from the coin chute 9. The push buttons 8 are preferably lamp buttons, which each include a light-emitting device and lights up when pushed by a player or used in lighting effects during game play.

The speaker 11 is installed inside the cabinet 1, and generates voice announcements and sound effects during game play.

The above-described components of the gaming machine are preferably controlled by a game controller unit that is preferably installed inside the cabinet 1. Alternatively, the game controller unit may be separated from the cabinet 1, and connected through a network to the components of the cabinet 1.

Referring to FIG. 2, the game controller unit includes a CPU 21, a ROM 22, a RAM 23, a credit controller unit 24, a console unit 25, a payout controller unit 26, a random-number generator unit 28, a lighting controller unit 29, a sound controller unit 30, and a display controller unit 31.

The CPU 21 runs various programs and thereby controls other components of the game controller unit according to instructions and data accepted by the console unit 25. The ROM 22 stores programs and databases used by the CPU 21. The RAM 23 temporarily stores variables, parameters, and the like that are used by the CPU 21.

The credit controller unit 24 manages the amount of player's credits, which is equivalent to the amount of coins and bills counted and validated by the counter/acceptor 24A. The console unit 25 monitors the push buttons 8 and accepts various instructions and data from the push buttons 8. The payout controller unit 26 changes player's credits to coins, bills, or other monetary data by using the coin hopper 26A or the like.

The random-number generator unit 28 generates and outputs random number(s) to the CPU 21. The random number will be used to randomly select an arrangement of stopped symbols and a type of symbols to be changed to a special symbol.

The lighting controller unit 29 controls lighting devices 29A installed in the three display units 3A, 3B, and 3C, the push buttons 8, and other lumps mounted on the cabinet 1 during game play. The lighting controller unit 29 thereby causes the lighting devices 29A to blink and/or change brightness and color in specific patterns in order to produces lighting effects. The sound controller 27 controls the speaker 11 to output voice announcements and sound effects during game play.

The display controller unit 31 controls the three display units 3A, 3B, and 3C to display various images on screens preferably by using computer graphics. The display controller unit 31 in particular controls video reels displayed on the middle display unit 3B by using computer graphics. FIG. 3 shows an example of a game screen 40 displayed on the middle display unit 3B. Preferably, five video reels 41A-41E are arranged on the game screen 40. Note that the number of video reels may be changed from five to other number, e.g., three. On each video reels 41A-41E, preferably three or more symbols 42 are repeatedly moved and stopped in a vertical direction. During moved, different types of symbols 42 appear at random or in a predetermined order. This action of symbols 42 is often referred to as “spins of video reels”. After a predetermined time has elapsed, symbols 42 will be stopped in an arrangement that the game controller unit randomly selects at a start of each game round. In stopped positions, symbols 42 are preferably aligned on one of three horizontal lines. In this case, all horizontal lines and slanted lines are preferably selectable as paylines. Alternatively, symbols may be stopped in a honeycomb arrangement. For example, if three or more symbols of the same type are aligned on a selected payline, a player will win an award depending on a bet placed on the payline and the type and number of the symbols aligned on the payline. The game screen 40 also includes a number of available credits, an amount of a bet placed at a game round, and an amount of a payout won at the game round.

In addition, the game screen 40 includes preferably four small regions in which four candidates 43A-43D for symbol types to be possibly changed to a special symbol are displayed in a static graphic form. Note that the number of the candidates 43A-43D may be changed from four to other number. The game controller unit randomly selects zero or more candidates 43A-43D to be changed to a special symbol at each game round. The special symbol is preferably interpreted as a wildcard symbol. The special symbol may have a different function, e.g., of indicating a bonus game or an extra payout to be provided to a player when appearing in an arrangement of stopped symbols. Among the candidates 43A-43D, one or more selected as being changed to special symbols will be prominently displayed on the respective small regions. Furthermore, symbols of the same type as the selected candidates will appear in a prominent form on the video reels 41A-41E. Referring to FIG. 4, three candidates, i.e., a cross symbol 43A, a circle symbol 43B, and a star symbol 43C are selected as special symbols 44A, 44B, and 44C, respectively. When the special symbols 44A-44C are interpreted as wildcard symbols, an arrangement of stopped symbols 42 shown in FIG. 4 includes a winning combination equivalent to five “seven” symbols 42D aligned on the second horizontal line, in contrast to the same arrangement without special symbols shown in FIG. 3. Thus, the larger number of the candidates are selected as being changed to special symbols, the better chances of winning are provided to a player.

The display controller unit 31 causes the middle display unit 3B to change selected candidates 43A-43C to special symbols 44A-44C while moving symbols 42 in a vertical direction. Preferably, the background color of these special symbols 44A-44C is changed to a color complementary to the background color of other normal symbols 42. For example, when the background color of normal symbols 42 is white, green, or bluish-purple, the background color of special symbols 44A-44C is black, red, or yellow, respectively. The colors of special symbols 44A-44C themselves may be changed to complementary colors. More preferably, colors of special symbols and their background are changed to a metallic color. Special symbols may be displayed in a blinking, flashing, or sparkling pattern by using computer-generated animation. These prominent changes in color and pattern of symbols enable a player to easily notice appearances of special symbols 44A-44C while symbols 42 are moved on the video reels 41A-41E. Note that the display controller unit 31 preferably provides a higher probability of displaying symbols 42A-42D of the same types as the four candidates 43A-43D at adjacent positions on the spinning video reels 41A-41D than symbols of other types. This can also cause a player to easily notice appearances of special symbols 44A-44C.

When two or more candidates are selected as special symbols, the selected candidates may be changed to special symbols at the same time while symbols 42 are moved. More preferably, the selected candidates are changed to special symbols in turn while symbols 42 are moved. Referring to FIGS. 5A-5C, three candidates 43A-43C are selected in advance, and will be changed to special symbols 44A-44C in turn. First as show in FIG. 5A, the first candidate 43A, i.e., cross symbols are changed to the first special symbols 44A after a predetermined time has elapsed from a start of moving symbols 42, i.e., a start of spins of the video reels 41A-41E. Next as show in FIG. 5B, the second candidate 43B, i.e., circle symbols are changed to the second special symbol 44B after another predetermined time has elapsed from the change of the first candidate 43A to the first special symbols 44A. Finally as show in FIG. 5C, the third candidate 43C, i.e., star symbols 44C are changed to the third special symbols 44C after another predetermined time has elapsed from the change of the second candidate 43B to the second special symbols 44B. In particular, a player can easily notice increase in types of special symbols 44A-44C not only on the video reels 41A-41E but also through the candidates 43A-43D displayed on the small regions. Note that the moving speeds of symbols 42 may be reduced each time types of special symbols are increased. Thus, a player is gradually excited each time he/she notices the increase in types of special symbols 44A-44C.

Referring to FIGS. 6A and 6B, operations of the gaming machine will be explained below in the order of the flow of a game round.

STEP S1: A player inserts coins or bills into the coin slot 5 or the bill slot 6, respectively. Then, the counter/acceptor 24A validates the coins and bills, and counts the valid coins and bills. The game controller unit reads the count and updates credit data stored in the RAM 23 to increase player's credits by the number corresponding to the count (cf. FIG. 2). Then, the player can place a desired bet on a desired payline by using the buttons 8. The console unit 25 accepts the bet placed on the desired payline. Then, the game controller unit enables the console unit 25 to accept a cue to start spinning of video reels 41A-41E from a spin button, one of the buttons 8. When the console unit 25 accepts the cue from the player who pushes the spin button 8, the game controller unit updates the credit data stored in the RAM 23 to decrease the amount of the credits by the total amount of the bets.

STEP S2: The game controller unit preferably causes the random number generator unit 28 to generate a random number, and then selects zero or more candidates for special symbols depending on the random number. The game controller unit preferably determines the number of symbol types to be changed to special symbols depending on the random number. When the number is determined to be zero, no candidates are to be changed to special symbols. When the number is determined to be one, the first candidate, i.e., cross symbols 43A are to be changed to special symbols 44A. When the number is determined to be two, the second candidate, i.e., circle symbols 43B are to be changed to special symbols 44B in addition to the first candidate 43A. When the number is determined to be three, the third candidate, i.e., star symbols 43C are to be changed to special symbols 44C in addition to the first candidates 43A and the second candidates 43B. When the number is determined to be four, the fourth candidate, i.e., “seven” symbols 43D are to be changed special symbols in addition to the first-third candidates 43A-43C. Thus, the game controller unit selects zero or more symbol types to be changed to special symbols at random. Preferably, the RAM 23 stores a flag linked to each symbol type in advance, and the game controller unit only sets the flags linked to the selected symbol types.

STEP S3: The game controller unit causes the random number generator unit 28 to generate five random numbers preferably. Each of the five random numbers is uniquely assigned to one of the video reels 41A-41E. The game controller unit then retrieves stop positions of the video reels 41A-41E linked to the five random numbers from respective stop position tables preferably stored in the ROM 22. Each of the stop position tables is assigned to one of the video reels 41A-41E, and represents relationship between random numbers and stop positions of the video reel, i.e., types of symbol columns to be displayed in static graphic forms on the video reel. Thus, the game controller unit selects stop positions of the video reels 41A-41E at random, and stores data representing the stop positions into the RAM 23, preferably.

The game controller unit also determines whether or not to provide an award to the player at random in the following manner. The game controller unit retrieves the five random numbers from a winning combination table stored in the ROM 22. The winning combination table represents relationship between combinations of five random numbers and awards. Here, the five random numbers are linked to the stop positions of the respective video reels 41A-41E. Accordingly, awards are assigned to winning combinations of symbols arranged on the stopped video reels. Preferably, winning combinations are assigned to arrangements where symbols of the same type (and a wildcard symbol) are stopped in three or more consecutive video reels. Types of awards depend on which types of symbols are repeatedly included in respective winning combinations. Note that the ROM 22 stores different types of winning combination tables that include different types of special symbols. The game controller unit has selected a type of a winning combination table in advance, preferably depending on the flags linked to symbol types. If the game controller unit retrieves an award linked to the combination of the five random numbers from the selected winning combination table, the game controller unit then decides to provide the award to the player.

STEP S4: The game controller unit instructs the display controller unit 31 to start the middle display unit 3B to spinning the video reels 41A-41E, i.e., continuously move symbols 42 in the vertical direction on the video reels 41A-41E. Each time a predetermined time has elapsed, the display controller unit 31 causes the middle display unit 3B to stop the video reels 41A-41E one by one into the respective stop positions selected in STEP S3. Details of STEP S4 will be described below.

STEP S5: If the game controller unit has decided to provide an award to the player, the game controller unit then controls visual and sound effects by providing the lighting controller unit 29 and the sound controller unit 30 with commands. The lighting controller unit 29 then turns on and off the lighting devices 29A in patterns represented by the commands. The sound controller unit 30 changes sounds reproduced from the speaker 11 to the sound effects represented by the commands. After that, the game controller unit updates the credit data stored in the RAM 23 to increase the player's credits by a payout to be provided as an award. If instructed by the player, the game controller unit may provide the player with the payout by using the payout controller unit 26. The game controller unit then waits a new instruction from the player. Alternatively, the game controller unit may start a bonus round to be provided to the player as an award.

In STEP S4, the display controller unit 31 preferably causes the middle display unit 3B to control spins and stops of the video reels 41A-41E as follows (cf. FIG. 6B).

STEP S401: The display controller unit 31 initializes various parameters for the control of the video reels 41A-41E, and in particular, sets an integer variable N to be 0 and a time variable TIME to be 0. In addition, a constant REEL_NUM is set to be 5 in advance, which represents the total number of the video reels 41A-41E.

STEP S402: The display controller unit 31 checks if the time variable TIME is larger than a constant REEL_STOP_TIME[N], which represents a predetermined time duration of the (N+1)-th video reel continuously spinning. If the time variable TIME is larger than the constant REEL_STOP_TIME[N], the process will be branched to STEP S410. Otherwise, the process will continue to STEP S403.

STEP S403: The display controller unit 31 first selects five symbol types to be “created” for the respective video reels 41A-41E. Here, the symbol types may be selected at random or in a predetermined order. The display controller unit 31 next accesses the RAM 23 and checks flags linked to the selected symbol types. If any flag has been set, the process will be branched to STEP S405. Otherwise, the process will continue to STEP S404.

STEP S404: The display controller unit 31 “creates” five symbols of the selected types in a normal graphic form on the respective video reels 41A-41E. More specifically, the display controller unit 31 prepares normal image data of the selected symbol types, which represents images of normal symbols 42 shown in FIG. 3, in a predetermined region of the RAM 23 or another memory unit.

STEP S405: When flags linked to one or more of the selected symbol types have been set, the selected symbol types include one or more candidates 43A-43D shown in FIG. 3. The display controller unit 31 checks if the time variable TIME is larger than a constant CHANGE_TIME, which represents the time to be required from the start of spins of the video reels 41A-41E until a selected candidate 43A-43C is changed to a special symbol 44A-44C, as shown in FIGS. 5A-5C. The constant CHANGE_TIME preferably varies with the candidates 43A-43D, and in particular, increases in the order of the first-fourth candidates 43A-43D. Alternatively, the constant CHANGE_TIME may be the same among the candidates 43A-43D. If the time variable TIME is larger than the constant CHANGE_TIME for any of the selected candidates 43A-43C, the process will continue to STEP S406. Otherwise, the process will return to STEP S404.

STEP S406: The display controller unit 31 first creates one or more of the selected candidates 43A-43C, for which the time variable TIME is larger than the respective constant CHANGE_TIME, in a “special” graphic form, i.e., a prominent graphic form as special symbols 44A-44C. The display controller unit 31 further creates symbols of the other selected types in a normal graphic form. The display controller unit 31 prepares image data of special symbols 44A-44C and normal symbols 42 in a predetermined region of the RAM 23 or another memory unit. The display controller unit 31 also changes image data of the selected candidates 43A-43C for use in displaying the small region to that of special symbols.

STEP S407: The display controller unit 31 causes the middle display unit 3B to display an animation of moving images of symbols 42 for a distance on the video reels 41A-41E by using image data of the symbols prepared in previous STEPS S404 or S406 in the predetermined regions of the RAM 23 or other memory unit. Note that the display controller unit 31 preferably reduces the moving speeds of the symbols 42 each time types of special symbols are increased. In addition, if any video reels 41A-41E has been determined to be stopped at STEP S410 described below, the moving speeds of symbols 42 on the video reels are gradually reduced, and then the symbols 42 will be stopped.

STEP S408: The display controller unit 31 increments the time variable TIME by a step.

STEP S409: The display controller unit 31 checks if the integer variable N is less than the constant REEL_NUM (e.g., 5). If the integer variable N is less than the constant REEL_NUM, the process will be repeated from STEP S402. Otherwise, the process will continue to STEP S5.

STEP S410: The display controller unit 31 determines the (N+1)-th video reel 41A, . . . , or 41E to be stopped. Then, symbols to be displayed in the stop position of the (N+1)-th video reel selected in STEP S3 will be created in order after a number of repetitions of STEP S404 or S406. After that, the symbols will be actually displayed in the stop position of the (N+1)-th video reel at STEP S407.

STEP S411: The display controller unit 31 increments the integer variable N by 1.

The display controller unit 31 repeats the loop of STEPS S402-S411 until the integer variable N reaches the constant REEL_NUM, i.e., the total number of the video reels 41A-41E, e.g., 5. Thus, the middle display unit 3B displays the spins and stops of the video reels 41A-41E for a game round. In particular, the selected candidates 43A-43C are prominently changed to the special symbols 44A-44C in turn as shown in FIGS. 5A-5B.

General Interpretation of Terms

In understanding the scope of the present invention, the term “configured” as used herein to describe a component, section or portion of a device includes hardware and/or software that is constructed and/or programmed to carry out the desired function. In understanding the scope of the present invention, the term “comprising” and its derivatives, as used herein, are intended to be open ended terms that specify the presence of the stated features, elements, components, groups, integers, and/or steps, but do not exclude the presence of other unstated features, elements, components, groups, integers and/or steps. The foregoing also applies to words having similar meanings such as the terms, “including”, “having” and their derivatives. Also, the terms “part,” “section,” “portion,” “member” or “element” when used in the singular can have the dual meaning of a single portion or a plurality of portions. Finally, terms of degree such as “substantially”, “about” and “approximately” as used herein mean a reasonable amount of deviation of the modified term such that the end result is not significantly changed. For example, these terms can be construed as including a deviation of at least ±5% of the modified term if this deviation would not negate the meaning of the word it modifies.

While only selected embodiments have been chosen to illustrate the present invention, it will be apparent to those skilled in the art from this disclosure that various changes and modifications can be made herein without departing from the scope of the invention as defined in the appended claims. Furthermore, the foregoing descriptions of the embodiments according to the present invention are provided for illustration only, and not for the purpose of limiting the invention as defined by the appended claims and their equivalents.

Claims

1. A gaming machine comprising

a display unit configured to display symbols using computer graphics, the symbols arranged in a plurality of columns, and moved and stopped on a column-by-column basis;

a console unit configured to accept monetary data and an instruction from a player to place a bet;

a game controller unit configured to execute a game program, and thereby control game functions of using the monetary data as a bet in response to the instruction, selecting zero or more types of symbols at random, determining an arrangement of symbols at random, retrieving a winning combination from the arrangement of symbols, and providing the player with an award depending on the bet and the winning combination retrieved from the arrangement of symbols; and

a display controller unit configured to cause the display unit to move symbols on a column-by-column basis, change a symbol of the type selected by the game controller unit to a special symbol while moving symbols, and then stop symbols in the arrangement selected by the game controller unit.

2. A gaming machine according to the claim 1, wherein the game controller unit is configured to interpret the special symbol as a wildcard symbol.

3. A gaming machine according to the claim 1, wherein the display controller unit is configured to cause the display unit to change a background color of the special symbol to a color complementary to a background color of other symbols while moving symbols.

4. A gaming machine according to the claim 1, wherein the display controller unit is configured to cause the display unit to display the special symbol in a blinking, flashing, or sparkling pattern while moving symbols.

5. A gaming machine according to the claim 1, wherein the display controller unit is configured to provide a higher probability of displaying candidates for a type of symbols to be changed to a special symbol at adjacent positions while the display unit moves symbols, than other types of symbols.

6. A gaming machine according to the claim 1, wherein

the display unit includes a region in which candidates for a type of symbols to be changed to a special symbol are displayed in a static graphic form, and

the display controller unit is configured to cause the display unit to change the candidate of a type has been selected by the game controller unit to a special symbol in the region while the display unit moves symbols.

7. A gaming machine according to the claim 1, wherein

when the game controller unit selects two or more types of symbols at random, the display controller unit causes the display unit to change symbols of the types selected by the game controller unit to special symbols in turn while moving symbols.

8. A method comprising

accepting monetary data and an instruction from a player to place a bet;

using the monetary data as a bet in response to the instruction;

selecting zero or more types of symbols at random;

determining an arrangement of symbols at random;

retrieving a winning combination from the arrangement of symbols;

displaying symbols by using computer graphics, the symbols arranged in a plurality of columns, and moved on a column-by-column basis;

changing symbols of the selected type to a special symbol while symbols are moved;

stopping symbols in the selected arrangement; and

providing the player with an award depending on the bet and the winning combination retrieved from the selected arrangement of symbols.