The usual Uno rules - Players race to empty their hands and catch opposing players with cards left in theirs, which score points. In turns, players attempt to play a card by matching its color or number to the topmost card on the discard pile. If unable to play, players draw cards from the draw pile until they are able to place a card. Wild and special cards spice things up a bit. Additionally, when playing their penultimate card from their hand, players must shout 'UNO' or face a forfeit of drawing two further cards. WHAT MAKES THIS DIFFERENT FROM TRADITIONAL UNO: Altimeter Alert Card. When played, the player of the altimeter alert card chooses one color and each player puts 1 card of that color, face down, in front of them. Then each player reveals their card and whoever has the highest number wins. If 2 players have the same card, the number is invalid and the next one who has the highest number wins. Whoever wins then plays his card and the game continues.