Gaming system and a method of gaming

A gaming system for playing a first game and a second game, the system comprising:

• a symbol selector configured to select a first plurality of subsets of symbols from a plurality of corresponding sets of symbols for the first game;
• an outcome generator configured to 1) determine an outcome of the first game based on the selected subsets of symbols, and 2) select, without input from a player, at least one of said selected subsets of symbols to be stored;
• a symbol store configured to store said at least one selected subsets of symbols in response to said first game outcome comprising at least one predefined symbol;
• and
• wherein said symbol selector is further configured to select a second plurality of subsets of symbols from said corresponding sets of symbols for the second game, and
• wherein said outcome generator is further configured to substitute said at least one selected subsets of symbols stored in the symbol store for at least one of said second subsets of symbols in response to said at least one selected subsets of symbols resulting in a more favourable win than said second subsets of symbols.