Patent attributes
A gaming system includes at least one input device adapted to receive a physical item associated with a monetary value that establishes a credit balance, an input indicative of a wager drawn from the credit balance for a wagering game, and a cashout input that initiates a payout from the credit balance. In response to a wager input, a wagering game is initiated. The gaming system includes an electronic display device adapted to display an active array of symbol positions that are populated by symbols randomly generated from one or more spins of a set of symbol-bearing reels. The active array may be progressively expanded in response to collecting a requisite number of special symbols among the randomly generated symbols at each active array size.
