PCT/AU2005/000368 Received 12 March 2006 TITLE: GAMING MACHINE FIELD OF THE INVENTION The present invention relates to gaming machines, The invention has been 5 developed primarily in relation to computerised gaming machines and will be described herein with reference to that application. However, it should be understood that the invention is not limited to that particular field of use and may be suitable for other applications, such as gaming facilitated by the internet. to BACKGROUND OF THE INVENTION Any discussion of the prior art throughout the specification should in no way be considered as an admission that such prior art is widely known or forms part of common general knowledge in the field. Gaming machines have long been known and are now one of the most 15 common forms of gambling. Usually gaming machines simulate a well-known game of chance. One of the oldest and best known forms of gaming machine is the rotating reel type "poker machine". In light of its popularity, the present invention will be described with reference to this type of gaming machine. However, it will be appreciated that the invention is equally applicable to gaming machines other than the 20 rotating reel type. Traditional poker machines use a series of three or more reels, each reel having symbols on its peripheral edge. The reels are rotated upon the placement of a bet and then stopped to produce an arrangement of randomly selected symbols. Winnings are paid if the random selection of symbols matches one of the predetermined winning 25 combinations. More recently, these gaming machines have been computerised with a video screen replacing the physically rotating reels. The display screen typically presents an array of symbols and five columns and three rows equating to the symbols that would normally be seen on the five physically rotating reels of an old-style mechanical machine. 30 Gaming machines can "pay winnings" in a variety of ways. These include dispensing money, dispensing tokens that can be redeemed for money, or simply Amended Sheet TDP A/ ATT PCT/AU2005/000368 Received 12 March 2006 -2 adding credits to a credit meter that can be used for placing future bets or redeemed as money. Given the predominance of computerised gaining machines, winnings are most commonly paid in the form of credits tallied on a credit meter. However, those skilled in the art will readily understand that the term encompasses other payment 5 mechanisms. Computerised machines have allowed players to simultaneously bet on the combination of symbols appearing in many different parts of the array. These parts of the array are referred to as "paylines" and consist of lines of adjacent symbols extending through the array. The symbols may be laterally or diagonally adjacent 10 each other so that the paylines can extend along each row and various angled or "zigzag" lines through the array. Most computerised gaming machines will offer at least five paylines in a five-reel array, which makes the gaming experience significantly more exciting than the old-style mechanical machines which traditionally had a single payline through the middle row of symbols. 15 Eventually, machines offered all the practical paylines in the five-column three-row array. Players come to expect machines to offer multiple paylines and game designers were forced to incorporate additional aspects of interest in order to attract players. As part of this ongoing effort to maintain player interest, many machines now 20 offer secondary or "feature" games. The feature appears upon some trigger event such as predetermined outcome in a primary or "base" game. The feature can be used to provide the player with relatively large winnings and thereby provides a strong incentive to continue playing the machine, As various different types of feature have been devised, several have proven to be particularly effective and popular. Different 25 versions are incorporated into many of the machines available today. One disadvantage associated with gaming machines which include feature games, is that the opportunity for triggering a feature game usually ends once the next primary game is played. Hence if the player does not choose to play the feature game at that time, the opportunity to play the feature game is lost, Amended Sheet PCT/AU2005/000368 Received 12 March 2006 -3 It is an object of the present invention to overcome or ameliorate at least one of the disadvantages of the prior art, or to provide a useful alternative. SUMMARY OF THE INVENTION 5 According to a first aspect of the invention there is provided a gaming machine including: a base game of chance having random outcomes which include predetermined winning outcomes, wherein said machine pays winnings upon the occurrence of any of said winning outcomes; 10 said machine being adapted to allocate feature qualifying attributes such that accumulation of one or more predetermined feature qualifying attributes opens a window of opportunity allowing a player to trigger a feature game at any time of their choosing whilst said window of opportunity is open; and said window of opportunity remains open until said player no longer holds said 15 one or more predetermined feature qualifying attributes. According to a second aspect of the invention there is provided a method of operating a gaming machine, the method including the steps of: providing a base game of chance having random outcomes which include predetermined winning outcomes, wherein said machine pays winnings upon the 20 occurrence of any of said winning outcomes; said machine being adapted to allocate feature qualifying attributes such that accumulation of one or more predetermined feature qualifying attributes opens a window of opportunity allowing a player to trigger a feature game at any time of their choosing whilst said window of opportunity is open; and 25 said window of opportunity remains open until said player no longer holds said one or more predetermined feature qualifying attributes. Preferably, different types of feature qualifying attributes are represented by corresponding feature qualifying symbols. Amended Sheet
PCT/AU2005/000368 Received 12 March 2006 -4 The feature qualifying attributes are preferably accumulated at random, in the event of the base game being played a predetermined number of times or during play of the base game on the occurrence of predetermined attribute awarding combinations, In a preferred form of the invention, feature attributes may be removed from a 5 player's tally once they have been used to trigger the feature game. Removal of the attributes may also occur at random, on the occurrence of a predetermined attribute removing combination occurring during play of the base game or in the event of the base game being played a predetermined number of times, Preferably, the characteristics of the feature game are dependent on the 10 accumulation of specific feature qualifying attributes which may result in the feature game including free games, win multipliers, substitutes symbols, bonus prizes, held reels, bonus reels, bonus scatter symbols, bonus substitute symbols and bonus trigger combinations which award further feature qualifying attributes. Varying levels of windows of opportunity are preferably provided such that 15 higher levels are perceived by a player as returning increased winnings. In one embodiment, the feature qualifying attributes are in the form ofjackpot qualifying attributes and the gaming machine is configured to provide ajackpot feature game which can be triggered by a player upon the accumulation of a predetermined number of jackpot qualifying attributes. 20 Preferably, when a player triggers the jackpot feature game, player interaction is required to win the jackpot, More preferably, when a player triggers the jackpot feature game, a secondary jackpot screen will appear for facilitating the player interaction, Preferably, the jackpot is contributed from a stand-alone machine or from a 25 number of machines networked together. In a particularly preferred form, the base game is a spinning reel type using a simulation of five adjacent wheels to present an array of randomly selected symbols in five columns and three rows. Amended Sheet
PCT/AU2005/000368 Received 12 March 2006 -5 BRIEF DESCRIPTION OF THE DRAWINGS Preferred embodiments of the invention will now be described, by way of example only, with reference to the accompanying drawings, in which: Figure 1 is a perspective view of a stand-alone gaming machine of the type 5 suitable for the present invention; and Figure 2 is a schematic representation of the gaming machine display showing a variety of arrays and paylines. DETAILED DESCRIPTION OF THE INVENTION 10 Referring to Figure 1, the gaming machine 1 has a video display screen 2 and control console 3. The control console 3 includes a coin slot 5 for inserting coins or tokens, a bank note slot 19, and a coin collection tray 6 for redeeming any winnings or unused coins or tokens. The console 3 also includes control buttons 4 for the player to select the number of paylines on which to bet, and, the number of credits they wish to 15 bet on each payline, The base game is a standard set of five reels, which present a five-column three-row array 7 of randomly selected symbols. The array 7 has seven paylines, 1-1 to 7-7 on which the player can place a bet, The payline icons 8 are placed on either side of the array 7 to more clearly indicate the configuration of each payline. 20 However, many variations of arrays and paylines may also be used. Any paylines carrying a bet and showing one of the predetermined winning combinations of symbols is a winning payline and credits are added to the player's credit meter (not shown). The gaming machine and method of playing the machine includes a base game 25 of chance having random outcomes which include predetermined winning outcomes, such that the machine pays winnings upon the occurrence of any of the winning outcomes. The gaming machine is adapted to allocate feature qualifying attributes during the play of the base game, Once a player accumulates one or more predetermined 30 feature qualifying attributes, a window of opportunity opens allowing a player to Amended Sheet
PCT/AU2005/000368 Received 12 March 2006 trigger the feature game at any time of their choosing whilst ever the window of opportunity remains open. The window of opportunity will remain open until the player no longer holds the predetermined feature qualifying attributes. Different types of feature qualifying attributes may be identified by corresponding feature qualifying 5 symbols. The feature qualifying attributes may be accumulated in a variety of ways including at random, when the base game is played a predetermined number of times or on the occurrence of predetermined attribute awarding combinations during play of the base game. 10 Once player has used some or all of their feature qualifying attributes to trigger the feature game, the spent attributes are subsequently removed from the player's tally. In other embodiments of the invention, the removal of the attributes may occur at random or on the occurrence of a predetermined attribute removing combination during play of the base game. Feature attributes may also be removed if the base is game is played a predetermined number of times. When a player triggers the feature game, the characteristics of that game are dependent on the accumulation of specific feature qualifying attributes. For example accumulation of specific attributes may result in a feature game which provides free games, win multipliers, substitute symbols, bonus prizes, held reels, bonus reels, 20 bonus scatter symbols, bonus substitute symbols or bonus trigger combinations which award further feature qualifying attributes, There may also be varying levels of windows of opportunity in which higher levels may be perceived by a player as returning increased winnings, In one embodiment, the feature qualifying attributes are in the form ofjackpot 25 qualifying attributes and the machine is configured to provide a jackpot feature game which can be triggered by a player upon accumulation of a predetermined number of jackpot qualifying attributes. Preferably, player interaction is required to determine if the jackpot is won. Upon triggering the jackpot game, the machine is configured to provide a secondary Amended Sheet.
PCT/AU2005/000368 Received 12 March 2006 -7 screen for facilitating the player Interaction, The prize for the jackpot may be contributed by a standalone machine or a number of machines networked together, In use, a player begins playing the base game and may be awarded feature qualifying attributes depending on the outcome the base game or the number of base 5 games played. The feature qualifying attributes may also be awarded at random. Once a player has accumulated the required amount or type of feature qualifying attributes, a window of opportunity opens for the player to start the feature game. If the played does not wish to play the feature game at that time, they may continue playing the base game in the hope of accumulating more feature qualifying 10 attributes, For example, a player may be awarded feature qualifying attributes which allow them to use a substitute symbol during play of the base game, If a player has recently won a large payout on a base game, they may not expect a winning combination to occur again for some time. Therefore in order to maximise their 15 chances of winning, they may wait a few turns before using the substitute symbol during play. Furthermore, a player may wait until they have accumulated a range of feature qualifying attributes which allow them to use features such as win multipliers or held reels and choose to use some or all of them at the one time, maximizing their chances of attaining a winning combination. Hence the invention allows the player 20 more options for their "gaming strategy". When the player chooses to use some or all of the feature qualifying attributes to play the feature game, the spent attributes are removed from their tally, The machine may also remove some or all of the feature qualifying attributes during play of the base game. Once a player no longer has enough feature qualifying attributes to 25 play the feature game, the window of opportunity closes until the player accumulates the required number or type of attributes for the window to open again, The present invention has been described herein by way of example only. Ordinary workers in this field will readily recognise many variations and modifications which do not depart from the spirit and scope of the broad inventive 30 concept. Amended Sheet