An electric toy gun having therein a power break control mechanism consisting of an actuator, a power break control set and a swinging block for breaking off power supply upon triggering of the trigger when the clip is empty. Both teams: secretly choose a strategy, generally by selecting a card placed face down; roll dice; reveal strategy choices by turning cards face up; determine a situation chart to consult, and further determine which result is selected from within the chart, based on some combination of which cards were played and the results of the dice rolls. The defect detection parameters define the permissible deviation of the surface image of a defective semiconductor wafer from that of a normal semiconductor wafer.