Gaming machine with symbol restriction

1. A computer-implemented method comprising:

determining, by one or more processors of a gaming machine, that a trigger event for a bonus game occurred during a base outcome event of a base game, wherein the base game and the bonus game are both reel-based games being executed on behalf of a client machine, wherein both the base game and the bonus game involve spinning a plurality of reels, each reel containing a respective plurality of symbols, to determine outcome events, and wherein a memory of the gaming machine stores respective pluralities of symbols for the reels;

in response to determining that the trigger event occurred, awarding, by the one or more processors, a number of spins of the reels in an instance of the bonus game, wherein a symbol counter is set to an initial value; and

until the awarded number of bonus game spins have been performed, the one or more processors repeatedly carrying out iterations of bonus game operations comprising:

selecting, from the stored pluralities of symbols for the reels, a symbol set for display on the plurality of reels, wherein the selected symbol set includes a number of a predetermined symbol equivalent to the symbol counter;

incrementing the symbol counter; and

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 the bonus game spin of the plurality of reels resulting in the selected symbol set, wherein displaying the bonus game spin comprises: displaying an animation of the plurality of reels spinning for a particular iteration of the bonus game, and before all of the plurality of reels finish spinning in the animation, indicating, on the client machine, selected positions for each of the predetermined symbols.

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

3. The method of claim 1 , wherein each reel comprises a respective cyclical sequence of symbols, and wherein selecting the symbol set for display on the plurality of reels comprises:

for each reel, randomly selecting a respective reel position that displays a subsequence of the symbols on the reel that are in the selected symbol set.

4. The method of claim 1 , wherein selecting the symbol set for display on the plurality of reels comprises simulating a spin of all reels.

5. The method of claim 1 , wherein the initial value of the symbol counter is at least 1.

6. The method of claim 1 , wherein incrementing the symbol counter comprises adding at least 1 to the symbol counter.

7. 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.

8. The method of claim 1 , wherein iterations of the bonus game operations further comprise:

determining a bonus payout amount associated with the selected symbol set; and

transmitting, to the client machine, an indication of the bonus payout amount.

9. The method of claim 8 , wherein the bonus payout amount is based on predetermined symbols displayed on the plurality of reels.

10. The method of claim 8 , wherein the client machine is associated with a credit account, and wherein the credit account is debited to play the base game, credited in response to the trigger event, and credited by the bonus payout amount.

11. 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.

12. A gaming system configured for 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 respective pluralities of symbols for the reels and a plurality of gaming device instructions, the gaming device instructions executable by the one or more gaming device processors to perform operations comprising:

determining that a trigger event for a bonus game occurred during a base outcome event of a base game, wherein the base game and the bonus game are both part of the reel-based game;

in response to determining that the trigger event occurred, awarding a number of spins of the reels in an instance of the bonus game, wherein a symbol counter is set to an initial value; and

until the awarded number of bonus game spins have been performed, repeatedly carrying out iterations of bonus game operations comprising:

selecting, from the stored pluralities of symbols for the reels, a first symbol set or a second symbol set for display on the plurality of reels, wherein the first symbol set excludes a predetermined symbol, wherein the second symbol set includes a number of the predetermined symbol equivalent to the symbol counter, and wherein, when the second symbol set is selected, the symbol counter is incremented, and

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 the bonus game spin of the plurality of reels resulting in the selected symbol set, wherein when the second symbol set is the selected symbol set displaying the bonus game spin comprises: displaying an animation of the plurality of reels spinning for a particular iteration of the bonus game, and before all of the plurality of reels finish spinning in the animation, indicating, on the client machine, selected positions for each of the predetermined symbols.

13. A computer-implemented method comprising:

determining, by one or more processors of a gaming machine, that a trigger event for a bonus game occurred during a base outcome event of a base game, wherein the base game and the bonus game are both reel-based games being executed on behalf of a client machine, wherein both the base game and the bonus game involve spinning a plurality of reels, each reel containing a respective plurality of symbols, to determine outcome events, and wherein a memory of the gaming machine stores respective pluralities of symbols for the reels;

in response to determining that the trigger event occurred, awarding, by the one or more processors, a number of spins of the reels in an instance of the bonus game, wherein the bonus game includes a predetermined symbol, and wherein a symbol counter is set to an initial value; and

until the awarded number of bonus game spins have been performed, the one or more processors repeatedly carrying out iterations of bonus game operations comprising:

selecting, from the stored pluralities of symbols for the reels, a symbol set for display on the plurality of reels, wherein the selected symbol set represents an outcome of a bonus game spin of the plurality of reels,

determining whether to replace symbols from the selected symbol set, wherein the replacement of symbols involves (i) replacing, with the predetermined symbol, a number of symbols from the selected symbol set equal to the symbol counter and (ii) incrementing the symbol counter, and

transmitting, to the client machine, a representation of the selected symbol set after replacement, wherein reception of the selected symbol set after replacement causes the client machine to display the bonus game spin of the plurality of reels resulting in the selected symbol set, wherein displaying the bonus game spin comprises: displaying an animation of the plurality of reels spinning for a particular iteration of the bonus game, and before all of the plurality of reels finish spinning in the animation, indicating, on the client machine, selected positions for each of the predetermined symbols.

14. The method of claim 13 , wherein, in the bonus game, the stored pluralities of symbols for the reels do not include the predetermined symbol.

15. The method of claim 13 , wherein each reel comprises a respective cyclical sequence of symbols, and wherein selecting the symbol set for display on the plurality of reels comprises:

for each reel, randomly selecting a respective reel position that displays a subsequence of the symbols on the reel that are in the selected symbol set.

16. The method of claim 13 , wherein iterations of the bonus game operations further comprise:

determining a bonus payout amount associated with the selected symbol set after replacement; and

transmitting, to the client machine, an indication of the bonus payout amount.

17. The method of claim 16 , wherein the bonus payout amount is based on predetermined symbols displayed on the plurality of reels.

18. The method of claim 16 , wherein the client machine is associated with a credit account, and wherein the credit account is debited to play the base game, credited in response to the trigger event, and credited by the bonus payout amount.