Pusoy derive from the popular Chinese Poker , it is also played in Hongkong with this card arrangement:
This Chinese gambling game is popular in Hong Kong and parts of Southeast Asia and is also played to some extent in the USA. It is known by several different names.
In Cantonese it is called Sap Sam Cheung, which means 13 cards, and in Vietnamese it is known by the similar name Xập Xám Chướng .
In Chinese, it is also sometimes called Luosong Pai Jiu , which I think means Russian Pai Gow. The game is indeed related to Pai Gow.
In the USA it is often known as Chinese Poker or sometimes Russian Poker, but note that some people also use the name Chinese Poker to refer to the climbing game Big Two.
In Hawaii it is called Pepito.
In the Phillipines it is known as Pusoy, again not to be confused with Pusoy Dos, which is Big Two.
Another name sometimes used is Good, Better, Best, referring to the three hands of a player.