A gaming system, game controller and method of gaming implementing a game wherein one or more symbols are selected to be retained from a previous game outcome based on symbols which contribute to a winning symbol combination in the game outcome. One or more subsequent game outcomes can be generated including the retained symbols. The retained symbols from a previous game outcome can be selected from symbols which contribute to a winning symbols combination in the previous game outcome. In the subsequent game outcome, the retained symbols can contribute to further winning symbol combinations.