 Three books written in Pahlavi, Kar-Namag i Ardashir i Pabagan, Khosrow and ridag, and Wizārišn ī čhatrang ("Treatise on Chess"), also known as the Chatrang Nama ("Book of Chess"), all mention "chatrang".In Kār-nāmak it is said that Ardashīr "with the help of the gods became more victorious and experienced than all others in polo, horsemanship, chess, backgammon, and other arts," and in the small treatise on Khosrow and ridag, the latter declares that he is superior to his comrades in chess, backgammon, and "hašt pāy".Bozorgmehr, the author of Wizārišn ī čhatrang, describes how the game of chess was sent as a test to Khosrow I (r. 531-79) by the "king of the Hindus Dēvsarm" with the envoy Takhtarītūs and how the test was answered by the vizier Bozorgmehr, who in his turn invented the game Backgammon as a test for the Hindus.