Teenagers call it the "yacha rule": promising not to report each other even if someone gets hurt, and then trading punches. It is slang for fighting with fists and feet without any protective gear, and some reportedly even write pledges in advance. According to a Seoul Economic Daily report, based on Ministry of Education data, the number of school violence review cases involving new forms of violence such as the yacha rule more than doubled, from 107 in the 2024 school year to 223 in the 2025 school year, and 160 cases were reviewed this year from March to August. Of the 243 victimized students counted through August this year, 173 (71.2%) were middle school students.
The fights usually take place in front of onlookers and are captured on mobile phone cameras. In September, in an underground parking lot of an apartment complex in Jeju City, two middle school students fought while about ten of their peers watched, and the police arrested both students at the scene on charges of special assault. In May, in a park in Cheongju, North Chungcheong Province, a woman in her twenties who had been forced to fight died while fighting two teenagers. The police arrested a man and a woman in their twenties who had forced the fight on charges of joint coercion, and applied charges of violence resulting in death to the two teenagers who took part in the assault.
The idea that "it's fine because we both agreed" apparently sounds quite plausible among children. The law, however, does not see it that way. This column explains in turn why an agreed fight becomes a crime, what liability the students who watched and filmed it bear, and what parents and schools should do.
1. A Promise Not to Report Has No Legal Force
A. The victim's consent and its limits
Article 24 of the Criminal Act provides that an act that infringes a legal interest with the consent of a person who is able to dispose of that interest is not punishable unless otherwise provided by law. This is precisely the logic that students who follow the yacha rule rely on. But courts do not allow everything simply because there was consent. For consent to remove unlawfulness, the consent itself must not be contrary to social norms ethically and morally.
Supreme Court Decision 2008Do9606, December 11, 2008The victim's consent that precludes unlawfulness must not only be given by a person who can legally dispose of the interest, but must also not be contrary to social norms ethically and morally.
This judgment concerned a case in which people conspired to inflict injuries on each other to obtain insurance money, but the legal principle is the same. Society will hardly tolerate a fight in which people punch each other in the face with bare fists in order to hurt each other, all the more so when the other party is a minor. A pledge is merely circumstantial evidence that the crime was planned in advance, not a document that reduces liability.
B. A claim of self-defense because both sides hit each other is also difficult
Because the side that was hit also struck back, it is easy to say, "I was hit first and only defended myself." But punches exchanged after agreeing to fight from the outset are an attack, not a defense.
Supreme Court Decision 2000Do228, March 28, 2000Where persons fight each other with the intent to attack, and one, having been attacked first, inflicts harm in response, that harmful act has the character of an attack as well as a defense, and therefore cannot be regarded as self-defense or excessive self-defense.
In the end, the two parties to a yacha rule fight each become both perpetrator and victim toward each other. It becomes a case of mutual assault.
2. Which Crimes Apply and How Serious Are They?
A. From assault to violence resulting in death
The crime of assault under Article 260(1) of the Criminal Act is punishable by imprisonment for not more than two years, a fine not exceeding 5 million won, misdemeanor imprisonment, or a minor fine. Because it is an offense for which no prosecution can be instituted if the victim does not want punishment, children assume that "it's over as long as nobody reports it." But once an injury results, it becomes the crime of bodily injury under Article 257(1) (imprisonment for not more than seven years, suspension of qualifications for not more than ten years, or a fine not exceeding 10 million won), and bodily injury is punished even if the victim does not want it. If a person dies as a result of the assault, under Articles 262 and 259(1), the offender is punished in the same manner as bodily injury resulting in death, by imprisonment for a limited term of at least three years. Falling and hitting one's head happens in an instant, and as the Cheongju case shows, the result cannot be undone.
B. Many onlookers make the crime more serious
Article 261 of the Criminal Act treats an assault committed by displaying the power of an organization or a crowd, or while carrying a dangerous object, as special assault, punishable by imprisonment for not more than five years or a fine not exceeding 10 million won. Special assault is not an offense that requires the victim's wish for punishment. Article 2(2) of the Punishment of Violences, etc. Act aggravates the punishment by up to one half of the penalty prescribed in the Criminal Act when two or more persons jointly commit assault, bodily injury, coercion, and the like, and paragraph (4) of the same Article provides that, in such cases, the rule that assault is not prosecuted against the victim's wishes does not apply. The moment several people surround one person and set up a fight, the promise "let's not report it" loses even more of its meaning.
C. Those who set up, egged on, and filmed the fight
A person who made others fight may be punished for coercion under Article 324(1) of the Criminal Act (imprisonment for not more than five years or a fine not exceeding 30 million won). Even without striking anyone directly, a person who aided the crime is punished as an accessory under Article 32 of the Criminal Act, with a penalty reduced from that of the principal offender. If someone cheered from the side to keep the fight going, or set the stage by agreeing to film it, liability for aiding may become an issue depending on the degree of participation. If the video was posted on social media to mock the victimized student, it constitutes cyber violence under Article 2, subparagraph 1-3 of the Act on the Prevention of and Countermeasures against Violence in Schools, and also spreads into criminal defamation and insult and civil damages.
3. School Procedures and Juvenile Procedures Run Separately
A. School violence review and measures
Article 2, subparagraph 1 of the Act on the Prevention of and Countermeasures against Violence in Schools defines school violence as acts that occur inside or outside school against students and that involve harm, such as bodily injury, assault, coercion, and cyber violence. Even if students agreed to fight in an underground parking lot outside school, it is school violence. Article 20(1) of the same Act requires anyone who witnesses school violence or learns of it to report it immediately to the school or other relevant authorities. A "no reporting" promise made among students means nothing in the face of this duty. Under Article 17(1), the review committee may request the superintendent of the education office to take measures ranging from a written apology to suspension from attendance, class transfer, transfer to another school, and expulsion (except during compulsory education). In a mutual fight, both students are reviewed as both perpetrating and victimized students.
B. Criminal procedures differ by age
Under Article 9 of the Criminal Act, a person under 14 years of age is not subject to criminal punishment. However, Article 4(1)2 of the Juvenile Act provides that a juvenile aged 10 or older but under 14 who commits an act in violation of criminal laws is to be heard as a protective case by the juvenile division, so protective dispositions may still be imposed. A person aged 14 or older is subject to criminal punishment, and depending on the case, the matter is either referred to the juvenile division or sent to a criminal trial. In yacha rule cases, where most participants are middle school students, the procedure may differ from student to student according to age, even within the same fight.
4. What Parents and Students Should Do Now
A. If your child was hurt
First, have your child examined at a hospital and obtain a medical certificate. If a video is spreading, save the post addresses and screen captures, and then request deletion from the platform. If deletion comes first, the evidence disappears. Report the matter to the school as school violence, and if the injury is serious or many people took part, consider filing a complaint with the investigative authorities. Even if your child is reluctant to report, saying "I agreed to it," you should calmly explain that the fact of consent does not erase the other party's liability.
B. If your child hit someone or watched
Do not let your child delete the conversations and videos left on the phone. It may be seen as destruction of evidence, and those materials may actually reveal who proposed the fight and who forced it. In a mutual fight, who proposed it first, whether the atmosphere allowed a refusal, and how badly someone was hurt determine the level of school measures and criminal punishment. Apologizing to the other student and compensating for medical costs are also tied to liability for damages under Article 750 of the Civil Act, so it is best to decide on the direction of a settlement while looking at both the school review and the investigation.
C. If a video is circulating
Resharing the video or mocking the victim in comments can by itself constitute new cyber violence. Do not spread videos you receive; if necessary, submit them only as evidence to the school or the investigative authorities.
5. Closing Thoughts
The yacha rule wraps violence up as a game under the word "agreement." But the law looks at injured bodies and remaining videos rather than at pledges written by children. A fight both sides agreed to is still assault; if someone gets hurt, it is bodily injury; and if there are many onlookers, it becomes special assault. It is necessary for education authorities to expand prevention education and discuss cooperation on deleting videos, but before that, adults must tell children clearly so that they break free of the illusion that "it's fine because we agreed not to report it." Keeping that promise is not loyalty; it is a way of letting a friend get hurt.
(Shin Dong-woo, Managing Partner, DAEON Law Firm)
This column provides general legal information based on Korean statutes and court decisions as of 2026. 10. 28.. It is not legal advice on any individual case.
2026. 10. 28. · By Attorney Dongwoo Shin
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