A method for conducting a wagering game includes receiving a wager to play the wagering game. A base array of symbol positions arranged in a plurality of columns is displayed. A plurality of symbols is randomly distributed such that each of the symbol positions in the base array is associated with one or more of the symbols. An extent by which the base array of symbol positions is to be expanded is indicated by the symbols. The base array of symbol positions is expanded into an expanded array of symbol positions including at least one additional symbol position.