Adrishta purusha sandhi is a form treaty, a concept of state policy. It is a form of alliance recommended for kings of certain kind. Manu mentions six sada gunas (requirements) of royal policy. These are – sandhi (alliance), vigraha (war), yana (marching), asana (inactivity), dvaidhi-bhava (dividing the army) and asraya (seeking protection). Kautilya supports this classification, but Acharya Vatavyadhi (Uddhava) is of the view that there are only two states – sandhi (alliance) and vigraha (war), the other four being implicit in these two. (Arthashastra 7.1).
Usually this type of alliance is sought by a weak king. This alliance becomes an Adrishta purusha sandhi when the weak king sends a representative to the stronger king with whom he is seeking alliance so as to avoid enmity with him. The treaty proposes that the weak king would undertake conquests or fight his enemies on behalf of the stronger king. This type of alliance gives the stronger king the option of not waging war against the enemy all by himself. While this alliance gives the weak king a chance of survival, it also helps in keeping peace with the stronger king by being subservient to him.
In the conclusion of a treaty or alliance, a king or his emissary, along with his army, meets the enemy king at a place not belonging to the enemy king. This alliance becomes an Adrishta purusha sandhi where a specific person authorized to represent the king or the king himself does not meet the enemy king but a representative meets the enemy king on behalf of the alliance-seeking king. Kamansaka, in his Nitisara supports this sandhi. He says that when a weak king makes an alliance with an enemy king and undertakes conquests on behalf of the enemy king, Adrishta purusha sandhi takes place. This type of alliance gives the king the option of not waging the war against the enemy’s enemy while being subservient to the enemy. The weak king attains his goal (alliance with an unseen party) through his secret gudhapurushas (agents).