According to the Han Feizi, a contemporary work on Legalist Philosophy, supporters of "Vertical Alliance" encourage the weak multitude to attack the one strong side whilst the Horizontal Alliance promote the one strong side attacking the weak multitude.
Moreover, they played a decisive role and were described as extremely powerful and capable, constantly struggling to manipulate the situation.
The seventh chapter of the "Benjing Yifu" appendix to the Guiguzi describes the mental and moral cultivation methods used by the School of Diplomacy; the "Benjing" covers the ideas behind the basic guiding principles whilst the "Yinfu" consists of very mysterious concealed writings.
The Guiguzi is a book of theory that is complete in every detail and very subtly written, making its ideas hard to express.
The Annals of the Warring States is a well-written rhetorical compendium the words and actions of the strategists of the School of Diplomacy who were all resourceful, intelligent, aware of the actual situation and gifted in the use of language.