GAMING MACHINE AND METHOD WITH AWARD MODIFIER TRIGGERED BY APPEARANCE OF A CATALYST SYMBOL

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

displaying, on an electronic display device, a plurality of symbol-bearing reels and an indicator, the indicator bearing a modifier; and

generating, by game-logic circuitry using a random number generator, a bonus game comprising a series of free spin outcomes, wherein for each spin outcome:

spinning and stopping the plurality of symbol-bearing reels to populate an array with landed symbols from the stopped reels;

in response to the landed symbols including a catalyst symbol:

displaying, on the electronic display device, an animation linking the catalyst symbol to each of any value-bearing symbols in the landed symbols, wherein the animation comprises an animation of the catalyst symbol moving from its original landing position in the array to the landing position of each of the one or more landed value-bearing symbols and, based on the modifier, modifying the value associated with each of the one or more landed value-bearing symbols;

awarding the modified values; and

modifying the modifier for a subsequent spin outcome based on a type of the catalyst symbol, the type of the catalyst symbol being one of a plurality of possible types; and

in response to the landed symbols including one or more value-bearing symbols but not the catalyst symbol:

not awarding values associated with the landed value-bearing symbols; and

maintaining the modifier for the subsequent spin outcome.

2 . The method of claim 1 , further including, for each spin outcome, modifying payouts associated with winning symbol combinations in the array based on the modifier and awarding the modified payouts.

3 . The method of claim 1 , wherein the value-bearing symbols bear respective credit amounts.

4 . The method of claim 1 , wherein the modifier is a pay multiplier.

5 . The method of claim 4 , wherein the possible types of the catalyst symbol are associated with respective different values of the pay multiplier, wherein the modifying operation includes modifying the value of the pay multiplier.

6 . The method of claim 1 , wherein the possible types of the catalyst symbol are represented by respective different colors of the catalyst symbol.

7 . The method of claim 1 , further comprising:

detecting, via at least one of one or more electronic input devices, a physical item associated with a monetary value that establishes a credit balance; and

receiving, via at least one of the one or more electronic input devices, a cashout input that initiates a payout from the credit balance.

8 . The method of claim 1 , wherein in response to the symbols including the catalyst symbol but no value-bearing symbols, modifying the modifier for a subsequent spin outcome based on the type of the catalyst symbol.

9 . A gaming system comprising:

a gaming machine including an electronic display device configured to display a plurality of symbol-bearing reels and an indicator, the indicator bearing a modifier; and

game-logic circuitry configured to perform the operations of generating, using a random number generator, a bonus game comprising a series of free spin outcomes, wherein for each spin outcome:

spinning and stopping the plurality of symbol-bearing reels to populate an array with landed symbols from the stopped reels;

in response to the landed symbols including one or more value-bearing symbols and a catalyst symbol:

displaying, on the electronic display device, an animation linking the catalyst symbol to each of the one or more value-bearing symbols in the landed symbols, wherein the animation comprises an animation of the catalyst symbol moving from its original landing position in the array to the landing position of each of the one or more landed value-bearing symbols and, based on the modifier, modifying the value associated with each of the one or more landed value-bearing symbols;

awarding the modified values; and

modifying the modifier for a subsequent spin outcome based on a type of the catalyst symbol, the type of the catalyst symbol being one of a plurality of possible types; and

in response to the symbols including one or more value-bearing symbols but not the catalyst symbol:

not awarding values associated with the value-bearing symbols; and

maintaining the modifier for the subsequent spin outcome.

10 . The gaming system of claim 9 , wherein, for each spin outcome, the game-logic circuitry is configured to perform the operations of modifying payouts associated with winning symbol combinations in the array based on the modifier and awarding the modified payouts.

11 . The gaming system of claim 9 , wherein the value-bearing symbols bear respective credit amounts.

12 . The gaming system of claim 9 , wherein the modifier is a pay multiplier.

13 . The gaming system of claim 12 , wherein the possible types of the catalyst symbol are associated with respective different values of the pay multiplier, wherein the modifying operation includes modifying the value of the pay multiplier.

14 . The gaming system of claim 9 , wherein the possible types of the catalyst symbol are represented by respective different colors of the catalyst symbol.

15 . The gaming system of claim 9 , wherein the game-logic circuitry is configured to perform the operations of:

detecting, via at least one of one or more electronic input devices, a physical item associated with a monetary value that establishes a credit balance; and

receiving, via at least one of the one or more electronic input devices, a cashout input that initiates a payout from the credit balance.

16 . The gaming system of claim 9 , wherein in response to the symbols including the catalyst symbol but no value-bearing symbols, the game-logic circuitry is configured to perform the operation of modifying the modifier for a subsequent spin outcome based on the type of the catalyst symbol.

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

displaying, on an electronic display device, a plurality of symbol-bearing reels and an indicator, the indicator bearing a pay multiplier; and

generating, by game-logic circuitry using a random number generator, a bonus game comprising a series of free spin outcomes, wherein for each spin outcome:

spinning and stopping the plurality of symbol-bearing reels to populate an array with landed symbols from the stopped reels;

awarding payouts for winning symbol combinations in the array multiplied by the pay multiplier;

in response to the landed symbols including one or more value-bearing symbols and a catalyst symbol:

displaying, on the electronic display device, an animation linking the catalyst symbol to each of the one or more value-bearing symbols in the landed symbols, wherein the animation comprises an animation of the catalyst symbol moving from its original landing position in the array to the landing position of each of the one or more landed value-bearing symbols;

awarding values associated with the one or more value-bearing symbols in the landed symbols multiplied by the pay multiplier; and

modifying the pay multiplier for a subsequent spin outcome based on a type of the catalyst symbol, the type of the catalyst symbol being one of a plurality of possible types; and

in response to the symbols including one or more value-bearing symbols but not the catalyst symbol:

not awarding values associated with the value-bearing symbols; and

maintaining the pay multiplier for the subsequent spin outcome.

18 . The method of claim 17 , wherein the possible types of the catalyst symbol are associated with respective different values of the pay multiplier, wherein the modifying operation includes modifying the value of the pay multiplier.

19 . The method of claim 17 , wherein in response to the symbols including the catalyst symbol but no value-bearing symbols, modifying the pay multiplier for a subsequent spin outcome based on the type of the catalyst symbol.

20 . The method of claim 17 , wherein each spin outcome comprises a catalyst symbol among the landed symbols.