When does a game of Mah Jongg end?

A game of American Mah Jongg ends when one player matches their 14 tiles to a hand on the published game card (eg, the National Mah Jongg League's Standard Hands and Rules card). If no players are able to achieve Mah Jongg, the game will end in what is termed a 'Wall Game'. Basically, the game runs through to the end and there are no longer any tiles remaining in the wall for a player to pick.