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.
From amazon.com you can obtain Pai Gow Tiles by Michael J. Musante, the classic book on Pai Gow rules and strategy.
Many casinos in the USA offer Pai Gow Poker, a game loosely based on Pai Gow, played with standard playing-cards.