The ninja's main job was the gathering of intelligence, but in order to do this they had to take part in all sorts of criminal acts, such as theft, fraud, trespassing, murder and arson. There needed to be laws and an understanding in place to see to it that ninja did not profit themselves from these actions. For example, such rules included, "Ninja techniques must not be abused", "Throw away your pride", "Never reveal secrets" and "Never allow your true self to be seen" amongst others. A guilty conscience, any semblance of hesitation or greed would hinder the ninja from doing his job. As represented by the kanji character '忍' (shinobi/nin = endurance), ninja had to cope with some harsh realities, and had to make sure they exercised strict self-control.
