Select 2-4 players. Press the button to start. When the sound stops and the trigger light goes from red to green, the last to press the trigger switch gets a shock! But be warned, if you press too soon…… For extreme fun why not switch over to Lighting Reaction Extreme mode? This time the fastest to press the trigger switch will NOT get a shock…but everyone else will! This product requires 3*AAA batteries (not included).