By some measures Uno is the top-selling card or board game in the world. It’s seemingly showing up everywhere – thanks in part to dozens of new editions published by maker Mattel each year.

If you grew up playing UNO with your family, the official rules of the game may surprise you. How to play UNO The object of the game is to play all the cards in your hand before the other players do.

UNO domination isn’t just about Draw 2s, Skips and Reverses, but those cards definitely help. By Deb Amlen On most days, Ray Adler, the global head of games for Mattel, carries a deck of UNO ...