How does the substitution jutsu work? Almost every character in the Naruto series, from minor character to boss level character, uses this jutsu 
Ever since I started watching the series, I wanted to know how this technique works. It may look like a Ninjutsu 101 technique in the early parts of the series, but in many of the serious fights later in the series, it seems to fool even the opponents who are well-versed in combat. Is this jutsu based on any real life technique?