The present invention relates to a gaming machine, methods of gaming and gaming systems. The gaming system comprises: a first video display; a second video display; and a game controller. The game controller is arranged to: select a plurality of symbols from a symbol set for display on the first video display and the second video display; and evaluate a symbol subset comprising one or more of the plurality of symbols to determine whether to make an award. The number of symbols of the symbol subset is higher than a number of symbols in the symbol subset evaluated by the game controller in a previous game instance.