are bonuses for winning the last trick with certain methods and for different types of slams. It can be adapted to be played with a standard 52-card deck. The earliest surviving rules were written by Pan Zhiheng around 1610. In this version (鬥天九), triple and quadruple tricks were not allowed and Heavens can beat Nines and the Supreme pair. There were also versions for two or three players in which some of the tiles remain undistributed. His rules are more similar to the ones used in northern China during the early 20th century than the Cantonese rules that are dominant in the present. They are also very similar to another game simply called dominoes (骨牌) played in many parts of China. Bagchen is a Tibetan variation played with a double set of dominoes. Daaluu (Даалуу) is a variation in Mongolia that also uses a double set and plays similarly to Khorol. History In his article Chinese Origin Of Playing Cards published in 1895, Sir William Henry Wilkinson pointed out that the game of Tien Gow was invented long before Song dynasty, but was standardized in 1120: [Quote from page 66. Note this publication predated the modern pinyin transliteration system] It is perfectly clear, indeed, that all that was done or asked for in 1120 was an imperial decision as to which of several forms or interpretations of the game now known as T'ien-kiu ("Heavens and Nines") was to be considered orthodox. The game and the cards must have been in existence long before. The passage from the Cheng-tzâ-t'ung [《正字通》] runs thus (s.v. p'ai [牌]): Also ya p'ai now the instruments of the game. A common legend states that in the second year of the Hsüan-ho [宣和二年], in the Sung dynasty [i.q. 1120 AD], a certain official memorialized the throne, praying that the ya p'ai (ivory cards [牙牌]) be fixed as a pack of 32, comprising 127 pips [sic, it should be 227, but Chinese printers are careless], in order to accord with the expanse of the stars and constellations. The combination 'heaven' [6/6, 6/6] consisted of two pieces, containing 24 pips, figures of the 24 solar periods; 'earth' [1/1, 1/1] also composed two pieces, but contained 4 pips, the 4 points of the compass - east, west, south, and north; 'man' [4/4, 4/4] two pieces, containing 16 pips, the virtues of humanity, benevolence, propriety, and wisdom, four-fold; 'harmony' [2/3, 1/3]