They were masters of Ninjutsu(The Art Of Stealth) the martial art of the ninja NOT Kung Fu. For those who can'
t tell the difference between samurais and ninjas a Samurai is more
like a soldier without guns but armed with Swords,Bows and arrows But Ninjas or Shinobi is more
like a guerrilla squad using Swords, Shuriken, Smoke Bombs, etc. Everything that
people believe in
like how ninjas can do anything
like run on water, make some hand seal and turn in to smoke and how
people think ninjas are demons that kill
people for no reason were wrong. The science of ninjas were higher and that's why they thought Ninjas were Magicians but they were only illusionist who fooled the eyes of the ignorant. Even the military uses the ninjas tactics and weapons like smoke grenades originally came from smoke
bomb. Samurai described ninjas from there experience from battles then later
people made up stories like how a ninja summoned a Giant Frog to Defeat it. Later on Masashi Kishimoto created Naruto the
anime cartoon episodes as seen in cartoon network based on Japanese folk stories. Ninjutsu contained Pressure points, Samurai Sword Techniques, Chinese Philosophies,Meditation,etc.
The code of the ninja(Ninpo) which was was against the code of the samurai (Bushido). The art of the Samurai was death. But the art of the ninja was to survive, get the job done and escape. This gave ninjas greater advantage. They also borrowed stealth tactics from Sun Tzu the Chinese general.
Example:
-Be extremely subtle,
even to the point of formlessness. Be extremely mysterious, even to the point of soundlessness. Thereby you can be the director of the opponent'
s fate.
-For to win one hundred victories in one hundred battles is not the acme of skill. To subdue the enemy without fighting is the acme of skill.
-Invincibility
lies in the defence; the possibility of victory in the attack.
these were all ninja tactics