Gaming machine with symbol accumulation

1. A computer-implemented method for symbol replacement in a reel-based game, wherein the reel-based game is executed by a gaming machine on behalf of a client machine, wherein the reel-based game includes a base game and a bonus game, both involving spinning a plurality of reels to determine outcome events, and wherein a memory stores respective pluralities of symbols for the reels, the method comprising:

selecting, by one or more processors and from the memory, a set of symbols associated with respective positions of each of the reels as a base outcome event of the base game;

determining, by the one or more processors, that the base outcome event includes a trigger event that causes execution of the bonus game;

selecting, by the one or more processors and from the memory, a first bonus set of symbols associated with respective positions of each of the reels as a first bonus outcome event of the bonus game;

incrementing, by the one or more processors, a bonus counter by a number of instances of a predetermined symbol, in the first bonus set of symbols, that do not contribute to any winning combination of symbols in the first bonus set of symbols based on a table of winning combinations for the bonus game;

determining, by the one or more processors, that the bonus counter is at least equal to a threshold number; and

selecting, by the one or more processors and from the memory, a second bonus set of symbols associated with respective positions of each of the reels as a second bonus outcome event of the bonus game, wherein the second bonus set of symbols includes at least the threshold number of instances of the predetermined symbol, and wherein the second bonus set of symbols includes a winning combination.

2. The method of claim 1 , further comprising:

after selecting the second bonus set of symbols, resetting the bonus counter to zero.

3. The method of claim 1 , wherein determining that the base outcome event includes the trigger event comprises:

awarding a number of consecutive bonus outcome events, wherein the consecutive bonus outcome events include the first bonus outcome event and the second bonus outcome event.

4. The method of claim 3 , further comprising:

determining that the awarded number of consecutive bonus outcome events have been played and that the bonus counter is non-zero; and

in response to determining that the awarded number of consecutive bonus outcome events have been played and that the bonus counter is non-zero, selecting a third bonus set of symbols associated with respective positions of each of the reels as a third bonus outcome event of the bonus game.

5. The method of claim 1 , wherein the predetermined symbol is a Wild symbol.

6. The method of claim 1 , wherein each reel comprises a respective cyclical sequence of symbols, and wherein selecting the first bonus set of symbols and the second bonus set of symbols comprises:

for each reel, randomly selecting a respective reel position that displays a subsequence of the symbols on the reel that are part of the first bonus set of symbols and the second bonus set of symbols, respectively.

7. The method of claim 1 , wherein selecting the first bonus set of symbols and the second bonus set of symbols comprises:

simulating a spin of all reels for each selected bonus set of symbols.

8. The method of claim 1 , wherein selecting each of the first bonus set of symbols and the second bonus set of symbols comprises:

transmitting, to the client machine, a representation of the selected symbol set, wherein reception of the selected symbol set causes the client machine to display a spin of the plurality of reels resulting in the selected symbol set.

9. The method of claim 8 , wherein incrementing the bonus counter by the number of instances of the predetermined symbol, in the first bonus set of symbols, that do not contribute to any winning combination comprises:

causing the client machine to display an animated avatar interacting with the reels to (i) remove the instances of the predetermined symbol in the first bonus set of symbols that do not contribute to any winning combination from the reels, and (ii) increment the bonus counter.

10. The method of claim 9 , wherein, in an iteration of the bonus game in which accumulated predetermined symbols are deployed into the selected symbol set, causing the client machine to display the spin comprises:

causing the client machine to display the animated avatar interacting with the reels to deploy the accumulated predetermined symbols.

11. The method of claim 1 , wherein both the base game and the bonus game have five reels and each of the five reels displays three symbols at a time.

12. The method of claim 1 , wherein the gaming machine simultaneously executes base games or bonus games in real time on behalf of at least 30 client machines, and wherein each of the at least 30 client machines communicates with the gaming machine by way of a wide-area packet-switched network.

13. The method of claim 1 , wherein an extent of accumulated symbols is displayed adjacent to the reels.

14. The method of claim 1 , wherein the threshold number is at least 2.

15. A gaming system configured for symbol replacement in a reel-based game, wherein the reel-based game is executed on behalf of a client machine, wherein the reel-based game involves spinning a plurality of reels to determine outcome events, the gaming system comprising:

a plurality of gaming devices each including at least one display device and a plurality of input devices including (i) an acceptor of a physical item associated with a monetary value, (ii) a validator configured to identify the physical item, and (iii) a cash-out button actuatable to cause an initiation of a payout associated with a credit account;

one or more gaming device processors; and

one or more gaming device memory devices storing (i) respective pluralities of symbols for the reels and (ii) a plurality of gaming device instructions executable by the one or more gaming device processors to perform operations comprising:

selecting, from the gaming device memory devices, a set of symbols associated with respective positions of each of the reels as a base outcome event of a base game, wherein the set of symbols is based on the pluralities of symbols;

determining that the base outcome event includes a trigger event that causes execution of a bonus game;

selecting, from the gaming device memory devices, a first bonus set of symbols associated with respective positions of each of the reels as a first bonus outcome event of the bonus game, wherein the first bonus set of symbols is based on the pluralities of symbols;

incrementing a bonus counter by a number of instances of a predetermined symbol, in the first bonus set of symbols, that do not contribute to any winning combination of symbols in the first bonus set of symbols based on a table of winning combinations for the bonus game;

determining that the bonus counter is at least equal to a threshold number; and

selecting, from the gaming device memory devices, a second bonus set of symbols associated with respective positions of each of the reels as a second bonus outcome event of the bonus game, wherein the second bonus set of symbols includes at least the threshold number of instances of the predetermined symbol, and wherein the second bonus set of symbols is based on the pluralities of symbols and includes a winning combination.

16. The gaming system of claim 15 , wherein the operations further comprise:

after selecting the second bonus set of symbols, resetting the bonus counter to zero.

17. The gaming system of claim 16 , wherein determining that the base outcome event includes the trigger event comprises awarding a number of consecutive bonus outcome events, wherein the consecutive bonus outcome events include the first bonus outcome event and the second bonus outcome event, and wherein the operations further comprise:

determining that the awarded number of consecutive bonus outcome events have been played and that the bonus counter is non-zero; and

in response to determining that the awarded number of consecutive bonus outcome events have been played and that the bonus counter is non-zero, selecting a third bonus set of symbols associated with respective positions of each of the reels as a third bonus outcome event of the bonus game.

18. The gaming system of claim 15 , wherein each reel comprises a respective cyclical sequence of symbols, and wherein selecting the first bonus set of symbols and the second bonus set of symbols comprises:

for each reel, randomly selecting a respective reel position that displays a subsequence of the symbols on the reel that are part of the first bonus set of symbols and the second bonus set of symbols, respectively.

19. The gaming system of claim 15 , wherein selecting each of the first bonus set of symbols and the second bonus set of symbols comprises:

transmitting, to the client machine, a representation of the selected symbol set, wherein reception of the selected symbol set causes the client machine to display a spin of the plurality of reels resulting in the selected symbol set.

20. A non-transitory computer readable medium having stored thereon instructions that, when executed by a computing device, cause the computing device to perform operations comprising:

selecting a set of symbols associated with respective positions of each of a plurality of reels as a base outcome event of a base game;

determining that the base outcome event includes a trigger event that causes execution of a bonus game;

selecting a first bonus set of symbols associated with respective positions of each of the plurality of reels as a first bonus outcome event of the bonus game;

incrementing a bonus counter by a number of instances of a predetermined symbol, in the first bonus set of symbols, that do not contribute to any winning combination of symbols in the first bonus set of symbols based on a table of winning combinations for the bonus game;

determining that the bonus counter is at least equal to a threshold number; and

selecting a second bonus set of symbols associated with respective positions of each of the plurality of reels as a second bonus outcome event of the bonus game, wherein the second bonus set of symbols includes at least the threshold number of instances of the predetermined symbol, and wherein the second bonus set of symbols includes a winning combination.