Patent attributes
A gaming machine includes an electronic display device configured to display an array of symbol positions and registers. The registers are associated with respective subsets of the symbol positions of the array. Game-logic circuitry directs the display device to animate a plurality of spins of symbol-bearing reels wherein, in each spin, the reels are spun and stopped to land symbols in the array. For each landed value-bearing symbol, the symbol value is added to the applicable register, and the landing position is tagged. In response to tagging all the symbol positions in a subset, that subset's register value is awarded and that subset's tags are cleared. In response to no value-bearing symbols landing in a subset during a reel spin, that subset's register and tags are cleared.