A gaming system includes a plurality of gaming machines and a continual game sequence including a plurality of symbols and a plurality of sessions. Each session includes a number of games. At the beginning of a game sequence, the gaming system draws all of the symbols. When the number of games of the current session has been played without a winner, the game sequence proceeds to the next session. For each session, the gaming system activates a number of the drawn symbols based on the session number. Upon player activation, a gaming machine generates a symbol subset, marking each symbol in the subset which matches the activated symbols. If the marked symbols match a predetermined pattern, the gaming system provides an award for a player, basing the award on an award pool amount and the session number. As the session number increases, the award provided to the player decreases.