Wagering system with improved expected value during a special event

1. A gaming system for playing a wagering game including a base game and a special event, the wagering game having a first expected value attributable to the base game and a second expected value attributable to the special event, the special event occurring in response to a triggering event during play of the base game; the gaming system comprising:

at least one input device;

at least one display device;

at least one controller;

at least one memory device storing instructions that, when executed by the at least one controller cause the system to:

receive, responsive to inputs via the at least one input device, wagers to play respective initial plays of the base game;

display, on the at least one display device, a randomly selected outcome of each initial play of the base game;

receive, responsive to inputs via the at least one input device, wagers to play respective subsequent plays of the base game, the subsequent plays being subsequent to the initial plays; and

display, on the at least one display device, a randomly selected outcome of each subsequent play of the base game, wherein the first expected value attributable to the base game decreases from the initial plays to the subsequent plays by making a game enhancement parameter available in the initial plays unavailable in the subsequent plays, and the second expected value attributable to the special event increases from the initial plays to the subsequent plays to compensate for decreasing the first expected value attributable to the base game.

2. The gaming system of claim 1 wherein the game enhancement parameter is a bonus award.

3. The gaming system of claim 1 wherein the game-enhancement parameter increases a probability of obtaining a winning outcome in the base game or includes a bonus multiplier.

4. The gaming system of claim 1 ,

wherein the randomly selected outcome is part of the first expected value attributable to the base game and is selected from a plurality of possible base game outcomes including at least one winning outcome; and

wherein the controller enables the display device to show the plurality of base game outcomes via a plurality of symbols arranged in an array.

5. The gaming system of claim 4 , wherein the symbols are shown on a plurality of reels and wherein the game-enhancement parameter enables the display of a wildcard symbol on one of the reels.

6. A method of conducting a wagering game including a base game and a special event, the special event occurring in response to a triggering event during play of the base game, the method comprising:

awarding, by at least one of one or more processors, a first game enhancement parameter with a first randomly-selected outcome selected from a first plurality of outcomes in the base game;

subsequent to awarding the first game enhancement parameter, awarding, by at least one of the one or more processors, a second game enhancement parameter with a second randomly-selected outcome selected from a second plurality of outcomes in the base game, the second game enhancement parameter being associated with a special event, the first game enhancement parameter being automatically made unavailable for award with the second plurality of outcomes;

determining, by at least one of the one or more processors, whether the special event is triggered; and

increasing, by at least one of the one or more processors, the probability of triggering the special event if the second game enhancement parameter has been awarded, the increasing of the probability of triggering the special event being related to a value lost from the first game enhancement parameter being made unavailable for award with the second plurality of outcomes.

7. The method of claim 6 , wherein the first game-enhancement parameter increases a probability of obtaining a winning outcome in the base game.

8. The method of claim 6 , wherein the first wagering-game enhancement parameter is a bonus multiplier increasing the value of a winning outcome in the base game.

9. The method of claim 6 , wherein the special event includes a bonus game or eligibility for a progressive award.

10. The method of claim 6 , further comprising:

determining a randomly-selected base game outcome in response to receiving a wager input from a player, the randomly-selected base game outcome being selected from a plurality of possible base game outcomes including at least one winning outcome; and

displaying the base game outcome on a display device, by a plurality of symbols arranged in an array, wherein the symbols are shown on a plurality of reels and the first game-enhancement parameter allows the display of a wild symbol on one of the reels.

11. A computer-implemented method for conducting a wagering game in a gaming system, the wagering game including a base game and a special event, the method comprising:

receiving, responsive to inputs via at least one input device, wagers to play respective plays of the base game, the plays including initial plays of the base game and subsequent plays of the base game, the subsequent plays being subsequent to the initial plays;

displaying, on at least one display device, a randomly selected outcome of each play of the base game;

during one or more of the initial plays of the base game, randomly awarding, by at least one of the one or more processors, at least one game enhancement parameter, the game enhancement parameter modifying one or more of the initial plays;

in response to completion of the initial plays of the base game, automatically excluding, by at least one of the one or more processors, the game enhancement parameter from being available for the subsequent plays;

during one or more of the subsequent plays of the base game, increasing a probability of triggering the special event; and

during one or more of the subsequent plays of the base game, triggering the special event.

12. The method of claim 11 , wherein the game enhancement parameter increases a probability of the outcome being a winning outcome or increases a value of the outcome if the outcome is a winning outcome.

13. The method of claim 11 , wherein triggering the special event in the one or more of the subsequent plays is unlocked during one of the initial plays of the base game.

14. The method of claim 11 , wherein the wagering game includes an overall expected value, the overall expected value including a first expected value attributable to the base game and a second expected value attributable to the special event, wherein the first expected value is greater during the initial plays than during the subsequent plays, and wherein the second expected value is greater during the subsequent plays than during the initial plays.