The series Graded Readers for Chinese Language Learners is composed of 50 books, divided into three subseries, namely folktales, literary stories and historical stories, corresponding to Levels 1-3 respectively.
 
The Corrupt Official’s Birthday Gift tells how Chao Gai, Wu Yong and the Ruan brothers took the birthday tribute escorted by Yang Zhi by strategy. Yang Zhi was from a military general’s family. Skilled in martial arts, he wanted to find an official position in the capital. But then he accidentally killed a rogue on the street and was therefore tattooed on the face and banished to Daming Prefecture where he was assigned the task of escorting the birthday tribute to the Prime Minister. Yang Zhi was extremely cautious, but still was robbed of the tribute by Chao Gai and a few others. Yang Zhi was so helpless he went to Erlong Mountain; he met Lu Zhishen on the way. Driven to a corner as wanted fugitives, Chao Gai and the others went to Liangshan. With Lin Chong’s help, Chao Gai became the new chief of Liangshan.