Ninjas were trained to be particularly secretive. As mercenaries and covert agents that emerged in feudal Japan, some of their functions included espionage, information gathering, infiltration, bodyguarding, and much more. Because ninjas were well-known for their stealth, many people have wondered if they assassinated people.
Ninjas may have assassinated people. Many assassinations in the feudal era were attributed to ninjas, but no proof exists to prove or verify these kills. During those tumultuous times, it was easy to kill almost anyone from simple rivals to liege lords and place the blame on disreputable ninjas.
The notion of ninjas being assassins is more of a product of legend and fantastic depictions in popular culture, both western and Japanese. This article will explore some of the different widely accepted truths about these warriors.
Who Were the Ninjas’ Enemies?
Ninjas’ were mercenaries who accepted money in exchange for their skills.
Ninjas’ enemies were whoever their employers dictated they were. A ninja’s employer determined whom they needed to spy on, steal from, terrorize, kill, or guard. Contrary to popular belief, samurais weren’t the natural enemies of ninjas.
Legends say that the peaceful monks taught others to do their fighting to protect their temples. Many of these people were peasants and farmers of their surrounding community.
These ordinary people were trained to become fighters, which then evolved to become warriors for hire.
Others believe the ninja evolved as an opposing force to the samurai – respectable upper-class warriors. 
Unlike the noble samurai, who fought in the open and followed a code of honor known as the Bushido (way of the warrior), the ninja were hired to do things that were considered unsavory.  These things included:
- Planting misinformation
- Organizing surprise attacks
- Guerilla warfare
Because of the ninjas’ methods of trickery, subterfuge, and ambush, they were much less regarded than the samurai.
Ninjas became highly active in the 15th century during the turbulent Sengoku Period and were hired mostly by daimyos (feudal lords) and sometimes to do the dirty work for samurai.  However, precedents of the ninja could be dated as early as the 12th century.
What Weapons Did Ninjas Use?
Ninjas mastered the use of many of the usual weapons of war.
Ninjas frequently used the following weapons common to other warriors of the era: the sword, spear, and bow. They also had specialized weapons like chained sickles and projectile blades. Many ninjas even used poisons.
The following sections will outline some of the ninjas’ most commonly used weapons in more detail.
A number of ninjas used this as their primary weapon, though their katanas were shorter and straighter than those samurai used. These features helped ensure that a ninja would not be constrained when having to fight indoors in enclosed spaces.
Ninjas’ katanas were also helpful for scaling walls. The handguard could be used as a step when the sword was propped against a wall. The cord attached to the handle made it easy for a ninja to hook their foot through and pull up the weapon so it would not be left behind.
This weapon was composed of a short-handled sickle with a 6.5-10 ft (2-3 meters) long chain attached. At the end of this chain was a metal weight. This weight could be twirled on the chain for longer-range attacks, and the sickle was used when an enemy managed to get in close.
The kusarigama was the weapon mainly associated with the ninja.
Shuriken (throwing weapons) came in different shapes, not just the popular iteration known as throwing stars or ninja stars. They could also be metal spikes 5 to 8 ½ inches (13-22 cm) long.
These projectile weapons were mainly used to take opponents out of combat and hit vital points and exposed parts like the hands, feet, and face.
When used for short-range attacks, shuriken could be used to deal lethal blows and even partially disembowel an enemy.
These were ninja caltrops. Makibishi were small; pointed iron junctions dropped on the ground to deter pursuers. They were hard to see, thus even more difficult to avoid during a chase. The makibishi were very useful, especially if the ninja had pursuers on horseback.
These wrist weapons are also known as the “hand claw.” These were used in hand-to-hand combat and were valuable in taking away an enemy’s sword. Other times, tekko-kagi were also used to assist a ninja when scaling walls.
These explosives used gunpowder and consisted of tiny packages covered in paper or wicker. They could release clouds of smoke or poison. Some of these bombs also included shrapnel to wound or disable enemies from a distance.
The popular kunai, a heavy pointed blade closely resembling a Japanese masonry trowel, is known as a ninja weapon in popular culture. However, these blades were more tools than weapons. They were used mainly to gouge holes in walls to assist in spy work.
Other weapons like blowguns, land mines, poisons, and cane swords were also associated with ninjas.
Did Ninjas Ever Lose in Combat?
Ninjas did not specialize in face-to-face combat. Their skills were focused on stealth, guerilla warfare, and information gathering.
Ninjas sometimes lost in combat. Because they were more focused on stealth and surprise attacks, if forced into a duel with enemies, these covert warriors were at a disadvantage. They did have some training in ninjutsu, but their combat skills wouldn’t match those of a samurai.
Ninjas were well-known spies, using disguises to hide their identities, playing the role of a farmer, blacksmith, monk, or merchant.
Kunoichi (female ninjas) were explicitly trained in infiltration, posing as geishas, dancers, and housemaids. It was easier for them to infiltrate castles and disguise intelligence activities as “women’s gossip.” They may have also been successful assassins.
If a ninja was an exceptional spy, they could spend almost the entirety of their lives living “ordinary lives.”
Most ninja activities had to be done in secret. Hence, a shinobi usually had a day job while the night was reserved for stealth and spying.
Shinobi were mercenaries trained in espionage, covert operations, and guerilla warfare methods. Their skills were not meant for face-to-face combat or dueling an enemy in the open.
Ninja weapons were made for speed and stealth, and most were not suited for head-on combat. Ninjas were at a severe disadvantage unless combat occurred on rough terrain or in mountainous areas and against smaller groups of enemies.
Assassination was one of the skills of ninja or shinobi. However, there is no solid proof for any assassinations attributed to ninjas.