Here is a list of the weapons Ninja used. It is probably incomplete as it is hard to find out all of the weapons the Ninja would have used as they were a very secretive society. But although it is incomplete it can give a general outline of the weapons they used.
The Ninja Nunchaku
In Japan as well as China the Nunchaku are used by many different martial arts. This is because the country’s Emperors at the time outlawed martial arts and training with weapons. The people had to make do with what they had and disguise the weapons as farming equipment.
Hence the birth of the Ninja Nunchaku.
Later in Japan the Ninja society adopted the Nunchaku as a weapon as it could be easily concealed but very dangerous in the hands of a well trained person. Ninjas were a group of highly trained, often from birth, assassins that were used by the powers of the time to assassinate people who did not comply with their requests.
Ninja Nunchaku come in a variety of designs and shapes. These include 2 link and 3 link chains and different shapes like circle/round, square or octagon. Sometimes the Ninja Nunchaku had spikes or round blunt ends to do maximum damage to enemies. Ninja Nunchaku were made out of wood most of the time and occasionally steel or a similar hard light metal. They came in various sizes, from very small to quite large, and to determine the proper length of the Ninja Nunchaku, they measured the length from the wrist to the elbow. That would give the ninja the greatest amount of movement and power to strike the enemy as well as the flexibility to maneuver if in trouble.
Ninja mostly fought in close proximity and the Nunchaku provided an excellent weapon at this close range. Being able to whip the Nunchaku up or down upon an unexpected opponent was the key to the ninjas surprise power. The Ninja Nunchaku were therefore very effective in close range battle. If the fight moved to a more long range fight the Nunchaku could easily be wrapped around the arm and a longer range weapon brought out to fight.