Wagering Game Having a Free-Play Bonus With a Variable Free-Play Retriggering Condition

1 . A gaming system comprising:

a wager input device for receiving a wager from a player;

a display configured to display a wagering game;

a memory device; and

a processor communicatively coupled to the display, the wager input device, and the memory device, the processor being configured to:

determine a retrigger condition for a wagering game feature;

conduct the wagering game feature;

determine if the retrigger condition for the wagering game feature was satisfied during play of the wagering game feature;

conduct another wagering game feature if the first retrigger condition was satisfied during play of the wagering game feature, the another wagering game feature having the same game format as the wagering game feature; and

determine another retrigger condition for the another wagering game feature, the another retrigger condition being different than the first retrigger condition.

2 . The gaming system of claim 1 , wherein the processor is configured to randomly determine at least one of the retrigger condition and the another retrigger condition.

3 . The gaming system of claim 1 , wherein the processor is configured to randomly determine at least one of the retrigger condition and the another retrigger condition by random selection from a weighted probability table.

4 . The gaming system of claim 3 , wherein the processor is configured to randomly determine the retrigger condition and the another retrigger condition for the wagering game feature by using different weighted probability tables.

5 . The gaming system of claim 1 , wherein a probability of achieving the another retrigger condition in the another wagering game feature is lower than a probability of achieving the retrigger condition in the wagering game feature.

6 . The gaming system of claim 1 , wherein the wagering game feature and the another wagering game feature each comprise a plurality of free spins of symbol-bearing reels.

7 . The gaming system of claim 1 , wherein at least one of the retrigger condition and the another retrigger condition comprises an occurrence of a particular symbol or symbol combination in a free spin of a plurality of reels.

8 . A gaming device comprising:

a wager input device for receiving a wager from a player;

a display configured to display a wagering game;

a memory device; and

a processor communicatively coupled to the display, the wager input device, and the memory device, the processor being configured to:

determine a first retrigger condition for a first wagering game feature;

conduct the first wagering game feature;

determine if the retrigger condition for the first wagering game feature was satisfied during play of the first wagering game feature;

conduct a second wagering game feature subsequent to completion of the first wagering game feature following at least one occurrence of the first retrigger condition during play of the first wagering game feature, the second wagering game feature having the same game format as the first wagering game feature; and

determine a second retrigger condition for the second wagering game feature, the second retrigger condition being different than the first retrigger condition.

9 . The gaming device of claim 8 , wherein the processor is configured to randomly determine at least one of the first retrigger condition and the second retrigger condition.

10 . The gaming device of claim 8 , wherein the processor is configured to randomly determine at least one of the first retrigger condition and the second retrigger condition by random selection from a weighted probability table.

11 . The gaming device of claim 10 , wherein the processor is configured to randomly determine the first retrigger condition and the second retrigger condition for the wagering game feature by using different weighted probability tables.

12 . The gaming device of claim 8 , wherein a probability of achieving the second retrigger condition in the second wagering game feature is lower than a probability of achieving the first retrigger condition in the first wagering game feature.

13 . A method of conducting a wagering game comprising the acts of:

using a wager input device to accept a player wager and to transform the player wager into an electronic data signal indicative of the wager;

using a user interface device to accept a player input;

using at least one processor to conduct a wagering game and to display on a display a randomly determined outcome;

using the at least one processor, or another processor, to execute a stored instruction set and perform the acts of:

triggering a first wagering game feature responsive to at least one predetermined randomly determined outcome in the wagering game;

determining a first retrigger condition for a first wagering game feature;

conducting the first wagering game feature;

determining if the first retrigger condition for the first wagering game feature was satisfied during play of the first wagering game feature;

conducting a second wagering game feature subsequent to completion of the first wagering game feature following at least one occurrence of the first retrigger condition during play of the first wagering game feature, the second wagering game feature having the same game format as the first wagering game feature; and

determining a second retrigger condition for the second wagering game feature, the second retrigger condition being different than the first retrigger condition.

14 . The method of claim 15 , wherein the act of using at least one of the processors to determine a first retrigger condition for the first wagering game feature comprises using the at least one of the processors to randomly determine the first retrigger condition, and wherein the act of using at least one of the processors to determine a second retrigger condition for the second wagering game feature comprises using the at least one of the processors to randomly determine the second retrigger condition.

15 . The method of claim 15 , wherein the act of using at least one of the processors to determine a first retrigger condition for the first wagering game feature comprises using the at least one of the processors to randomly determine the first retrigger condition by random selection from a weighted probability table stored in a memory device, and wherein the act of using at least one of the processors to determine a second retrigger condition for the second wagering game feature comprises using the at least one of the processors to randomly determine the second retrigger condition by random selection from a weighted probability table stored in a memory device.

16 . A method of conducting a wagering game on a wagering game terminal, the method comprising the acts of:

conducting a base wagering game on the wagering game terminal;

satisfying a precondition for entry into a wagering game feature during the act of conducting the base wagering game;

randomly determining, prior to conducting the wagering game feature, a retrigger condition from amongst a plurality of available retrigger conditions;

conducting the wagering game feature;

determining if the randomly determined retrigger condition for the wagering game feature was satisfied during play of the wagering game feature; and

randomly determining, prior to conducting another wagering game feature having the same game format as the wagering game feature, another retrigger condition from amongst the plurality of available retrigger conditions, the another retrigger condition being different than the retrigger condition.

17 . The method of claim 19 , wherein the act of randomly determining a retrigger condition from amongst a plurality of available retrigger conditions comprises using a processor to randomly determine the retrigger condition, and wherein the act of randomly determining another retrigger condition from amongst the plurality of available retrigger conditions comprises using the same processor or another processor to randomly determine the another retrigger condition.

18 . The method of claim 19 , wherein the act of randomly determining a retrigger condition from amongst a plurality of available retrigger conditions comprises using a processor to randomly determine the first retrigger condition by random selection from a weighted probability table stored in a memory device, and wherein the act of randomly determining another retrigger condition from amongst the plurality of available retrigger conditions comprises using the same processor or another processor to randomly determine the another retrigger condition by random selection from a weighted probability table stored in the memory device or in another memory device.

19 . The method of claim 21 , wherein the weighted probability table used to determine the retrigger condition is different than the weighted probability table used to determine the another retrigger condition.

20 . A computer program product comprising a computer readable medium having an instruction set borne thereby, the instruction set being configured to cause, upon execution by a controller, the acts of:

conducting a base wagering game on a wagering game terminal;

determining whether or not a precondition for entry into a wagering game feature was satisfied in connection with the conduct of the base wagering game;

randomly determining using the controller, prior to conducting the wagering game feature, a retrigger condition from amongst a plurality of available retrigger conditions;

conducting the wagering game feature on the wagering game terminal;

determining using the controller whether or not the randomly determined retrigger condition for the wagering game feature was satisfied during play of the wagering game feature; and

randomly determining using the controller, prior to conducting another wagering game feature having the same game format as the wagering game feature, another retrigger condition from amongst the plurality of available retrigger conditions, the another retrigger condition being different than the first retrigger condition.