Although some of the Yema-po coins may have been used by the Chinese laborers for monetary exchange within the Chinese community and/or as magical/medical paraphernalia, it is likely that most were used as gambling tokens in the popular game of fan t'an . Fan t'an never achieved great popularity in the Euro-American community, but it possessed great allure and excitement for the nineteenth century overseas Chinese. To play the game, a number of coins are hidden under a cover. The principle behind the game is that after betting, the number of coins is revealed and divided by four. The player's bet is on the remainder, or the number of coins left after the division process. The nineteenth century players made wagers with wen, special glass counters, and other chips.
In 1891 Stewart Culin published a description of his observations of the game of fan t'an. This descriptions provides a number of details that are helpful in understanding the use of wen and other artifacts at Yema-po and other overseas Chinese sites:
"The coins used in playing fan t'an are those of the present dynasty (i.e., Ch'ing), such as are now current in China, and are imported expressly for gambling purposes in large quantities. Only perfect pieces, and preferably those of the same mintage, are selected, and these are cleaned with vinegar and afterward polished by being shaken with damp sawdust in a cotton bag. Those of the Kanghi (K'ang Hsi) period (1661-1722 A.D.), and of the Kienlung (Ch'ien Lung) period (1735-1796 A.D.), which constitute a large part of the present circulation in China, are generally used, but pieces representing all the emperors of the Manchu dynasty except the present ruler, may be found upon these strings of cash. Some of the strings of cash of the periods already referred to appear to be quite uncirculated, and are probably reproductions made expressly for gambling purposes. The brass cash are not used as counters upon the board, leaden pieces from Annam called nai ts'in, "dirt cash", being substittued to prevent confusion."
In addition to the fan t'an coin counters, several special counters were used in the game: pak-chu, ("white pearls") represented $1; hak-chu, ("black pearls") represented $5; chessmen represented $10; and dominoes represented $50.
Twenty-one hemispherical glass blobs, in white and black and probably repesenting pak-chu and hak-chu counters, were excavated at Yema-po. The counters average 1.2 cm in diameter and 0.6 cm in height; they appear to have been made by placing a bead of molten glass on a smooth surface. As the bead cooled it formed a round counter with one flat and one convex surface. Fourteen pak-chu ("white pearls") and seven hak chu ("black pearls") were recovered at Yema-po.
The distribution of coins in the Yema-po excavations also provides evidence concerning the possible use of the coins as gambling tokens. Twelve of the 25 Asian coins were excavated from units on the west end of the upper terrace. On the map below the number of coins found in each unit is shown and a possible gambling area of the site is indicated by the green overlay.