Gaming machine and method with persistence feature

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

displaying an array of symbol positions and registers on an electronic display device of the gaming machine, the registers being associated with respective subsets of the symbol positions of the array;

animating, by the electronic display device, a plurality of spins of symbol-bearing reels wherein, in each spin, the symbol-bearing reels are spun and stopped to land a plurality of symbols borne by the reels in the array, the plurality of symbols including value-bearing symbols;

for each value-bearing symbol in the plurality of symbols,

visually adding, by the electronic display device, a value borne by the value-bearing symbol to the register associated with the subset containing the symbol position in which the value-bearing symbol landed, and

animating, by the electronic display device, the array to tag the symbol position in which the value-bearing symbol landed;

in response to tagging all the symbol positions in that subset, presenting, by the electronic display device, an award for the value in the register associated with that subset; and

in response to none of the value-bearing symbols landing in that subset during any one of the plurality of spins,

visually resetting, by the electronic display device, the value in the register associated with that subset, and

animating, by the electronic display device, the array to untag all the symbol positions in that subset.

2. The method of claim 1 , wherein the array includes a plurality of columns, the plurality of columns being the respective subsets, the registers being adjacent to the respective columns.

3. The method of claim 1 , wherein the array includes a plurality of rows, the plurality of rows being the respective subsets, the registers being adjacent to the respective rows.

4. The method of claim 1 , wherein the operation of animating the array to tag the symbol position in which the value-bearing symbol landed includes visually applying, by the electronic display device, a border, color change, background change, watermark, or other distinguishing characteristic to the symbol position.

5. The method of claim 1 , wherein further in response to tagging all the symbol positions in that subset, animating, by the electronic display device, the array to untag all the symbol positions in that subset.

6. The method of claim 1 , wherein the resetting operation includes resetting the value in the register associated with that subset to a variable non-zero value.

7. A gaming system comprising:

a gaming machine including an electronic display device configured to display an array of symbol positions and registers, the registers being associated with respective subsets of the symbol positions of the array, and

game-logic circuitry configured to perform the operations of:

animating, via the electronic display device, a plurality of spins of symbol-bearing reels wherein, in each spin, the symbol-bearing reels are spun and stopped to land a plurality of symbols borne by the reels in the array, the plurality of symbols including value-bearing symbols;

for each value-bearing symbol in the plurality of symbols,

visually adding, via the electronic display device, a value borne by the value-bearing symbol to the register associated with the subset containing the symbol position in which the value-bearing symbol landed, and

animating, via the electronic display device, the array to tag the symbol position in which the value-bearing symbol landed;

in response to tagging all the symbol positions in that subset, presenting, via the electronic display device, an award for the value in the register associated with that subset; and

in response to none of the value-bearing symbols landing in that subset during any one of the plurality of spins,

visually resetting, via the electronic display device, the value in the register associated with that subset, and

animating, via the electronic display device, the array to untag all the symbol positions in that subset.

8. The gaming system of claim 7 , wherein the array includes a plurality of columns, the plurality of columns being the respective subsets, the registers being adjacent to the respective columns.

9. The gaming system of claim 7 , wherein the array includes a plurality of rows, the plurality of rows being the respective subsets, the registers being adjacent to the respective rows.

10. The gaming system of claim 7 , wherein the operation of animating the array to tag the symbol position in which the value-bearing symbol landed includes visually applying, via the electronic display device, a border, color change, background change, watermark, or other distinguishing characteristic to the symbol position.

11. The gaming system of claim 7 , wherein in response to tagging all the symbol positions in that subset, the game-logic circuitry is further configured to perform the operation of animating, via the electronic display device, the array to untag all the symbol positions in that subset.

12. The gaming system of claim 7 , wherein the resetting operation includes resetting the value in the register associated with that subset to a variable non-zero value.

13. A gaming machine comprising:

an electronic display device configured to display an array of symbol positions and registers, the registers being associated with respective subsets of the symbol positions of the array; and

game-logic circuitry configured to perform the operations of:

animating, via the electronic display device, a plurality of spins of symbol-bearing reels wherein, in each spin, the symbol-bearing reels are spun and stopped to land a plurality of symbols borne by the reels in the array, the plurality of symbols including value-bearing symbols;

for each value-bearing symbol in the plurality of symbols,

visually adding, via the electronic display device, a value borne by the value-bearing symbol to the register associated with the subset containing the symbol position in which the value-bearing symbol landed, and

animating, via the electronic display device, the array to tag the symbol position in which the value-bearing symbol landed;

in response to tagging all the symbol positions in that subset, presenting, via the electronic display device, an award for the value in the register associated with that subset; and

in response to none of the value-bearing symbols landing in that subset during any one of the plurality of spins,

visually resetting, via the electronic display device, the value in the register associated with that subset, and

animating, via the electronic display device, the array to untag all the symbol positions in that subset.

14. The gaming machine of claim 13 , wherein the array includes a plurality of columns, the plurality of columns being the respective subsets, the registers being adjacent to the respective columns.

15. The gaming machine of claim 13 , wherein the array includes a plurality of rows, the plurality of rows being the respective subsets, the registers being adjacent to the respective rows.

16. The gaming machine of claim 13 , wherein the operation of animating the array to tag the symbol position in which the value-bearing symbol landed includes visually applying, via the electronic display device, a border, color change, background change, watermark, or other distinguishing characteristic to the symbol position.

17. The gaming machine of claim 13 , wherein in response to tagging all the symbol positions in that subset, the game-logic circuitry is further configured to perform the operation of animating, via the electronic display device, the array to untag all the symbol positions in that subset.

18. The gaming machine of claim 13 , wherein the resetting operation includes resetting the value in the register associated with that subset to a variable non-zero value.