A gaming machine comprising a plurality of grid positions, and a game controller to at least: randomly populate a plurality of grid positions with one of a plurality of grid symbols, receive one or more selections of the plurality of grid positions, resulting a plurality of unselected grid positions, reveal a plurality of unrevealed symbols at each of the plurality of grid positions selected, in response to a first grid position selected revealing the first symbol, repopulate the first grid position with one of a plurality of chance symbols including the first symbol and the second symbol, and in response to the first grid position selected revealing the second symbol, determine a first award based on the second symbol.