唐玄宗時的「安史之亂」，李光弼與叛將史思明在河陽隔著河對峙不下，史軍有一千多匹好馬，軍隊實力強過李軍。這一群馬每天都會到河邊洗澡，李光弼看著看著，突然想到一條妙計。他叫屬下把軍中所有母馬都集中起來，算算有五百匹母馬，接著又將小馬關到城裡面，等到史軍的馬在河邊洗澡時，把所有母馬趕出來，因為母馬想念小馬，便開始嘶叫起來，馬群中的公馬們一聽到母馬叫，異性相吸的緣故，自然會往母馬的方向跑，原本馬群中的母馬也跟過來。就這樣，史思明軍中的馬都跟著李光弼的母馬，全數游過了河跑到城裡，千匹好馬自然全都被李光弼接收，佔為己有。史思明的軍力頓時被削減一大半，這就是有名的「美馬計」。
三十六計之第三十一計：美人計
利用人類的天性－貪圖美色，來吸引對方後，再進一步消磨掉他的鬥志，因為再英勇善戰的將官，大多過不了「美人」這一關。
During the An Shih Rebellion of the Tang Dynasty, the government army was led by the general Li Guang Bi, and the rebel army was led by the general Shih Sih Ming. The two armies stalemated on opposite sides of He Yang River. The rebel army had more than one thousand fine horses and was in better condition than the government army.
The rebel army's horses came to the riverbank to bath everyday. Watching them by the river gave Li Guang Bi a brilliant idea. He ordered his men to assemble all the mares in their camp. There were about five hundred mares. Then he ordered all the ponies to be taken away and locked inside the city gates. That day, when the horses from the rebel army arrived at the river again for their daily bath, Li Guang Bi released all his mares to his side of the riverbank. Because the ponies had all been taken away, the mares started to whinny and call out for their youngsters. Hearing the calls and attracted by the mares, the stallions from the rebel army waded across the river. And the mares soon followed across too.
In an instant, all one thousand rebel horses became government property. The strength of the rebel army was decimated as a result. This is the famous historical story of the "Pretty Mares Trap"
Strategy 31: The Beauty Trap
Using beauty and sex as a weapon to distract the enemy and drain him of his fighting spirit. Even the bravest warrior is likely to be entrapped by beauty.
