背刺，网络流行语，在游戏中，这个词源自游戏《Dota》中隐形刺客的技能，指某个职业、英雄的技能，简单的说就是“背后一击”，在别人不注意的时候给予一个致命的打击。现实中可以理解为背后捅刀子。
Backstab, an internet buzzword, originates from the skill of the stealth assassin in the game Dota. It refers to a skill of a class or hero, and simply means “a strike from behind,” delivering a fatal blow when someone is least expecting it. In real life, it can be understood as stabbing someone in the back.
本义
即从身后将尖锐物体刺进对方的背部。在ACG作品中，背刺行为常出现在有刺客、盗贼身份的人身上。在一些游戏中也有背后一击的概念，往往在敌人背后攻击造成的伤害更高或更容易产生暴击。如暴雪魔兽地图DOTA中英雄—隐形刺客力丸的技能，英雄联盟中人物萨科（恶魔小丑）的技能。
汉语中有“背后捅刀子”的俗语，指的是“暗地里中伤、陷害他人”，且更常形容在熟人身上。于之意思相同的英语俗语“back-stab”直译过来就是“背刺”。
衍生义
基于它的本义，在网络上，背刺指个人、组织、平台毫无预料的行为使一方遭到打脸、感到不适，甚至感到利益受损，认为此前的投入和付出都白费了。这时我们也可以称利益受损的一方被背刺了。
一般用于贬义语境，被背刺的一方多多少少会对背刺者产生反感，以至于失去对背刺一方的信任。但也有例外，如在“朋友之间相互背刺”语境中可以理解成朋友之间小打小闹，此时无贬义。
Original Meaning
This refers to stabbing an opponent in the back with a sharp object. In ACG games, backstabs are often seen by assassins and rogues. Some games also have the concept of a backstab, where attacks from behind often inflict greater damage or are more likely to result in a critical hit. Examples include the skill of Rikimaru, the stealth assassin hero in Blizzard’s Warcraft map Dota, and the skill of Shaco (the demonic clown) in League of Legends.
In Chinese, the idiom “backstabbing” refers to “secretly slandering or framing someone,” and is often applied to an acquaintance. The English idiom “back-stab,” which has the same meaning, literally translates to “backstab.”
Derived Meanings
Based on its original meaning, backstabbing online refers to an unexpected action by an individual, organization, or platform that causes a party to feel humiliated, uncomfortable, or even harmed, leading to a feeling that all previous efforts and efforts have been wasted. In this context, we can also say that the party who suffered the loss has been backstabbed.
It is generally used in a derogatory context, where the person being backstabbed develops some degree of resentment towards the backstabber, leading to a loss of trust in the backstabber. However, there are exceptions. For example, in the context of “friends backstabbing each other,” it can be understood as a minor quarrel between friends, without any derogatory connotation.