A machine includes a display, a processor, and a computer readable medium storing program instructions, that when executed by the processor, cause a set of functions to be performed that include making a first determination that a first trigger event occurred; responsive to the first determination, selecting a multiplier symbol set from a multiplier symbol group, and for a or each multiplier symbol of the selected multiplier symbol set, determining a respective corresponding arrangement position that indicates a significant figure of a bonus multiplier; making a second determination whether or not a second trigger event occurred; responsive to the second determination, when the second trigger event occurred: selecting a further multiplier symbol from the multiplier symbol group, augmenting a magnitude of the bonus multiplier based on the further multiplier symbol, and displaying the augmented bonus multiplier; and when the second trigger event did not occur: displaying the bonus multiplier.