This is a gambling game played with Chinese dominoes. The set consists of all pairs of numbers from 1-1 to 6-6, with the following eleven tiles duplicated: 6-6, 6-5, 6-4, 6-1, 5-5, 5-1, 4-4, 3-3, 3-1, 2-2, 1-1. There are 32 tiles in all.
Each player receives four tiles and forms them into two pairs, as does the banker. If both the player's pairs outrank the banker's pairs the player wins, if neither does the banker wins, and if just one does it is a draw.
The rules of Pai Gow, compiled by Joe Celko, can be found on this site at paigow.html. An earlier version of the same page is available at the Game Cabinet.
The ICA Pai Gow page offers a Pai Gow computer program as well as rules, information about the game, and a set of MSWord documents intended to be printed on business cards to produce a cardboard set of annotated dominoes for practice.
Many casinos in the USA offer Pai Gow Poker, a game loosely based on Pai Gow, played with standard playing-cards.