In 210 BC, Emperor Qin Shi Huang，the First Emperor of Qin, died of illness. Eunuch Zhao Gao refused to let his eldest son Fusu inherit the throne and instead wanted his youngest son Hu Hai to become emperor. He colluded with Hu Hai and threatened the Prime Minister Li Si, strictly guarding the secret of Qin Shi Huang's death and not issuing a funeral. He also forged a decree, ordered the death of Fu Su, and appointed Hu Hai as the Crown Prince. Then, it was announced that Qin Shi Huang had passed away and was succeeded by Crown Prince Hu Hai as Emperor Qin II.
Zhao Gao made great contributions to Hu Hai and became the Prime Minister. However Zhao Gao was not satisfied at this position, he planned to usurp the throne and become emperor himself. He was also worried that the civil and military officials would not be satisfied, so he came up with a trick and conducted an experiment first.
One day, while the courtiers were paying their respects to Emperor Qin II, Zhao Gao had a deer brought to him and said, “This is a thousand mile horse, and I specially offer it to Your Majesty.”
Qin Ershi examined over and over. It was clearly a deer, but how could Zhao Gao say it was a horse? He smiled and said, “Did the Prime Minister make a mistake? This is a deer, how can we say it's a horse.”
Zhao Gao ignored Hu Hai's words and sternly asked the ministers around him, “Tell me, is this a deer or a horse?”
Some ministers were in fear of Zhao Gao's power and dared not speak up. Some people flatter Zhao Gao just to please him: “You are right, Prime Minister, this must be a horse. I raised such a horse a few years ago!” Som ministers, unwilling to go against their conscience, bluntly said," It's a deer, not a horse.”
Zhao Gao believed that those who spoke the truth were unwilling to submit to his command, and thus imposed various charges on them, such as being expelled from the court or killed.
This is actually a poisonous trick to force people to take sides, in order to see clearly which people are on one's side, which people are on the opposite side, and which people are neutral.
公元前210年，秦始皇病死，宦官赵高不愿让秦始皇的大儿子扶苏继承皇位，而想让秦始皇的小儿子胡亥当皇帝。便和胡亥串通一气，并且威胁丞相李斯，对于秦始皇的死讯严守机密，秘不发丧，并伪造诏书，赐死扶苏，立胡亥为太子。然后，才宣布秦始皇已经死去，由太子胡亥继承皇帝，称为秦二世。
赵高为胡亥立了大功，当了丞相。虽然至此，赵高并不满足，而是打算篡位自己当皇帝。他又担心文武百官不服，于是想一个花招，先做一次实验。
一天，赵高趁群臣朝拜秦二世时，让人牵来一只鹿献给秦二世，说：“这是一匹千里马，我特意敬献给陛下。”
秦二世左看右看，这明明是一只鹿，赵高怎么说是马呢？便笑着说：“丞相弄错了吧？这是一只鹿，怎么说是马呢？”
赵高没有理会胡亥的话，一本正经地厉声问左右的大臣们：“你们说说，这到底是鹿还是马？”
大臣们有的惧怕赵高的权势，不敢做声；有的为了讨好赵高，就阿奉承地说；“丞相说得对，这肯定是马，前些年我还养过这样的马呢！”也有的大臣不愿违背自己的良心，直言不讳地说：“是鹿，不是马！”
赵高认为说实话的人，是不甘心屈从他的指挥的，就给他们强加上种种罪名或被赶出朝廷，或被杀害。
这实际上是一条毒计，来强迫人们站队，以此来看清楚哪些人是站在自己一方的、哪些人是站在自己的对立面的、哪些人是处于中立的。
