**IF** the switches are simple series SPNO switches as shown and **IF** the LEDs are standard LEDs then by definition it is not possible - he is using video fakery and the demo is less than valueless. "Not possible" is able to be said with certainty because examining even SW1 + SW2 + SW3 in series current can flow only when all 3 are operated. HOWEVER if the "switches" and "LEDs" are modified then it is possible and it becomesa conjuring trick with rigged props. Still pretty pointless, but possible. One of various ways: - Each switch contains a current determining circuit. - Each LED contains a window comparator and current bypass circuitry - LED1 lights for I1 or (I1 + I2) or (I1 + I3) or (I1 + I2 + I3) eg say I1 = 10 mA, I2 = 20 mA, I3 = 40 mA. LED 1 will light at 10, 30, 50 and 70 MA LED2 will light for 20, 30, 60, 70 mA LED 3 will light for 40, 50, 60, 70 mA So mA LEDS lit 10 001 20 010 30 011 40 100 50 101 60 110 70 111 Hopefully that table looks familiar. _______________ There are many other trick ways and it is more likely that the system is "a trick". .