Gaming machine and method with symbol array alteration

A method of operating a gaming machine, the method comprising the operations of:

• displaying, on an electronic display device, a meter and a plurality of symbol-bearing reels comprising an array of symbol positions, the array of symbol positions comprising a plurality of rows and columns, each symbol position populated by a respective independent reel;
• conducting a first spin of the symbol bearing reels to land symbols on the reels in the symbol positions of the respective rows of the array;
• incrementing the displayed meter, by game-logic circuitry, according to a first amount based on any winning symbol combinations appearing along left-to-right ways and top-to-bottom ways after the first spin, wherein the symbols of the winning symbol combinations along the left-to-right ways appear in respective consecutive ones of the columns starting with the leftmost symbol position of each row, wherein the symbols of the winning symbol combinations along the top-to-bottom ways appear in respective consecutive ones of the rows starting from the topmost row;
• and
• in response to a first triggering event, conducting, by the game-logic circuitry, a series of free games wherein:
• in response to a second triggering event, displaying, on the electronic display device, an animation of expansion of the array comprising expanding one or more of the rows of the array to add one or more symbol positions to each expanded row, wherein the expanded array is center aligned, and wherein the expanding includes expanding each of the one or more rows by a same number of symbol positions in opposite directions, and wherein any given row of the array can only expand if such expansion would cause that row to be no more than a predetermined number of positions larger than the number of symbol positions in any other row;
• conducting an additional spin of the symbol bearing reels to land symbols on the reels in the symbol positions of the respective rows of the expanded array;
• and
• incrementing the displayed meter, by the game-logic circuitry, according to an additional amount based on any winning symbol combinations appearing along the left-to-right ways and the top-to-bottom ways after the additional spin.

A gaming system comprising:

• a gaming machine including an electronic display device configured to display a meter and a plurality of symbol-bearing reels comprising an array of symbol positions, the array of symbol positions comprising a plurality of rows and columns, each symbol position populated by a respective independent reel;
• and
• game-logic circuitry configured to perform the operations of:
• conducting a first spin of the symbol bearing reels to land symbols on the reels in the symbol positions of the array;
• incrementing the displayed meter according to a first amount for any winning symbol combinations along the rows and the columns of the array after the first spin;
• in response to a triggering event, displaying, on the electronic display device, an animation of expansion of the array comprising expanding one or more of the rows of the array to add one or more symbol positions to each expanded row, wherein the expanded array is center aligned, and wherein the expanding includes expanding each of the one or more rows by a same number of symbol positions in opposite directions, and wherein any given row of the array can only expand if such expansion would cause that row to be no more than a predetermined number of positions larger than the number of symbol positions in any other row;
• conducting a second spin of the symbol-bearing reels to land symbols on the reels in the symbol positions of the expanded array;
• and
• incrementing the displayed meter according to a second amount, by the game-logic circuitry, based on any winning symbol combinations along the rows and the columns of the expanded array after the second spin.