Gaming machine with expandable symbol matrix

1. Gaming machine comprising:

a symbol display device including a plurality of variable display areas and being configured so that symbol arrays each of which is constituted by arranged symbols are variably displayed in the variable display areas respectively, and then some of the symbols of the symbol arrays are respectively rearranged, on a one to one basis, in a plurality of blocks arranged in a matrix of M columns by N rows in the plurality of variable display areas; and

a controller configured to execute a game and to control the symbol display device so that the symbols are rearranged in accordance with the game,

the controller configured to execute the following steps of:

accepting, via a game medium acceptor, a game medium with a monetary value which establishes a credit balance for the player;

receiving, via a bet input device, a bet whose amount is designated by the player based on the credit balance;

executing a game as a result of the player's bet;

determining whether a predetermined condition is satisfied before the rearrangement of the symbols;

when the predetermined condition is not satisfied, setting a plurality of active lines in a display frame defined by the blocks in the matrix of M columns by N rows, each of the active lines being a combination of blocks made by selecting one block from the blocks in each of the variable display areas;

when the predetermined condition is satisfied, adding blocks to the blocks in the display frame to form a matrix of blocks of M columns by N+α rows, and setting, in the expanded display frame, additional active lines, the number of which is calculated by multiplying the number of the added rows, α , by a predetermined value; and

when a combination of a predetermined number of more of the symbols of a kind is achieved on any of the active lines, awarding a line payout in accordance with the type of the combination achieved,

wherein the controller randomly determines whether the predetermined condition is satisfied, based on a window number random determination table in which each of row numbers is associated with a corresponding one of weights, and

wherein the controller determines that the predetermined condition is not satisfied when the row number randomly determined based on the weights indicates N rows.

2. A gaming machine comprising:

a symbol display device including a plurality of variable display areas and being configured so that symbol arrays each of which is constituted by arranged symbols are variably displayed in the variable display areas respectively, and then some of the symbols of the symbol arrays are respectively rearranged, on a one to one basis, in a plurality of blocks arranged in a matrix of M columns by N rows in the plurality of variable display areas; and

a controller configured to execute a game and to control the symbol display device so that the symbols are rearranged in accordance with the game,

the controller configured to execute the following steps of:

accepting, via a game medium acceptor, a game medium with a monetary value which establishes a credit balance for the player;

receiving, via a bet input device, a bet whose amount is designated by the player based on the credit balance;

executing a game as a result of the player's bet;

determining whether a predetermined condition is satisfied before the rearrangement of the symbols;

when the predetermined condition is not satisfied, setting a plurality of active lines in a display frame defined by the blocks in the matrix of M columns by N rows, each of the active lines being a combination of blocks made by selecting one block from the blocks in each of the variable display areas;

when the predetermined condition is satisfied, adding blocks to the blocks in the display frame to form a matrix of blocks of M columns by N+α rows, and setting, in the expanded display frame, additional active lines, the number of which is calculated by multiplying the number of the added rows, α , by a predetermined value; and

when a combination of a predetermined number of more of the symbols of a kind is achieved on any of the active lines, awarding a line payout in accordance with the type of the combination achieved,

wherein the controller sets the active lines in the matrix of the blocks of M columns by N+α rows arranged in the display frame by adding the additional active lines, the number of which is equal to the predetermined value, to the active lines in the matrix of the blocks of M columns by N+α−1 rows arranged in the display frame.

3. The gaming machine according to claim 1 , wherein the number of the added rows is determined by a number of rows which the row number randomly determined based on the weights indicates.

4. The gaming machine according to claim 1 , wherein the additional active lines includes first additional active lines formed by the (N+α−1)-th row and second additional active lines formed by the (N+α)-th row, and

wherein the second additional active lines are arranged in the matrix of blocks of M columns by N+α rows in the same manner as the first additional active lines are arranged in the matrix of blocks of M columns by (N+α−1) rows.

5. The gaming machine according to claim 1 , wherein when a basic active line set including a plurality of first additional active lines formed by M columns by K rows exists, additional active line set candidates including a plurality of second additional active lines are generated by shifting the first additional active lines by one row, and

wherein third additional active lines are selected from the additional active line set candidates by excluding additional active lines overlapped with the first additional active lines from the additional active line set candidates such that an active line set including the first additional active lines and the third additional active lines are formed by M columns by (K+1) rows.

6. The gaming machine according to claim 2 , wherein the controller randomly determines whether the predetermined condition is satisfied, based on a window number random determination table in which each of row numbers to be is associated with a corresponding one of weights, and

wherein the controller determines that the predetermined condition is not satisfied when the row number randomly determined based on the weights indicates N rows.

7. The gaming machine according to claim 6 , wherein the number of the added rows is determined by a number of rows which the row number randomly determined based on the weights indicates.

8. The gaming machine according to claim 2 , wherein the additional active lines includes first additional active lines formed by the (N+α−1)-th row and second additional active lines formed by the (N+α)-th row, and

wherein the second additional active lines are arranged in the matrix of blocks of M columns by N+α rows in the same manner as the first additional active lines are arranged in the matrix of blocks of M columns by (N+α−1) rows.

9. The gaming machine according to claim 2 , wherein when a basic active line set including a plurality of first additional active lines formed by M columns by K rows exists, additional active line set candidates including a plurality of second additional active lines are generated by shifting the first additional active lines by one row, and

wherein third additional active lines are selected from the additional active line set candidates by excluding additional active lines overlapped with the first additional active lines from the additional active line set candidates such that an active line set including the first additional active lines and the third additional active lines are formed by M columns by (K+1) rows.