The trigger for multiplier growth shapes the pacing of a round. Designs where the figure rises by one on every spin regardless of outcome guarantee that the final spins are always the most valuable, whereas designs that increase it only on winning combinations can leave a round stuck at 1x for its entire length. Watching bonus buy slots with multiplier feature growth tied to spins rather than wins produces a steady, predictable build, while the win-triggered version feels more erratic. Both approaches are common, and the rules state which applies.