US Patent 11183019 System and method for providing a feature game

A gaming machine includes a game controller that initiates play of a base game in response to a first input received via a player interface. In response to initiating the play of the base game, the game controller selects and displays first symbols at base game display positions displayed on a display device, and determines that a feature game has been triggered in response to a trigger condition. For each game of the feature game, the game controller selects and displays replacement symbols for display at feature game display positions not containing configurable symbols. In response to the feature game display positions displaying a first predetermined quantity of configurable symbols, the game controller expands the feature game display positions to include one or more additional feature game display positions.