Kirisute-gomen was a right allowing samurai to strike down commoners, or those below their rank, who had insulted them, their honor or their position in any way, and to leave the body where it lay, without fear of indemnity or punishment.
Samurai had the right to cut down commoners
Only a single cut could be made
The right to use such action was permitted when cases of extreme rudeness, hindrance of a samurai’s official functions, slight or slur, defamation, deliberate attack on, or conflict with a samurai arose.
Also known as Burei-uchi, and the older term, Uchisute, the rules of practice demanded that the right be effected immediately upon the offence, and not against past offences. It should also be achieved in a single cut. Should the initial strike fail to instantly kill the opposition, a secondary cut, or coup de grace was not permitted. It also allowed lesser ranked samurai the right to defend themselves against such an attack from their superiors, but only with their wakizashi, short sword, and not with their main katana or tachi.
The rules for engagement, conditions for its use and follow up actions were strictly enforced.
The nearest government office was to be notified of the act promptly after the killing, and a full explanation was to be forthcoming. The samurai was expected to then spend the following 20 or more days in home detention for the responsibility of having taken a life. The blade used may be temporarily confiscated as evidence for inspection. Witnesses to the act would be required to confirm that the behavior of the person killed and justification of the act of Kirisute-gomen.
If no witnesses to the act could be found, then it was possible that the samurai would be dismissed from his position, in worse cases his home and property confiscated, and his family dispossessed. At worst, a samurai may be ordered to commit seppuku, or even be beheaded for his actions. Often in such cases the family and friends of a samurai who had exercised his right to Kirisute-gomen would do their best to find witnesses.
The rules of engagement were strictly enforced
Knowing the situation, there were townsfolk who would deliberately try to provoke a samurai into action, and so to diffuse the situation, during the mid Edo period, sword stations for the depositing of swords at places such as theaters, public entertainments and public bath houses were established. Feudal lords arriving in Edo during the periods of alternative service known as Sankin Kotai, would often visit local magistrates upon their arrival in Edo, and provide them with gifts in anticipation of light sentencing for any of their entourage should such an occurrence take place.