UNO is a card game where players try to get rid of all their cards by playing cards that match either the number or color of previously played cards. When a player plays all of his cards, he collects his opponents' cards and adds them up to determine their score.
UNO can be played with two to ten players, ages seven and up. Players are given seven cards face down, and the remaining cards are used as a deck. The top card of the deck is flipped over and used as the discard pile. Players take turns selecting cards from their hand which match the card on top of the discard pile. If, for example, the card is a blue 6, players may either play blue cards or sixes. If they are unable to play, their turn is forfeited.
In addition to number cards, there are also "reverse," "skip," "draw two," "wild" and "wild draw four" cards. Reverse cards reverse the order in which turns are taken, for example from clockwise to counter-clockwise. Skip cards skip over the following players turn. "Draw two" cards force the following player to draw two cards from the deck. Wild cards can be used on top of any colored card on the discard pile. "Wild draw four" cards can be used on top of any card and forces the following player to draw four cards.
Play continues until any player has used all their cards. The winner collects all of the opponent cards and adds them up to determine a score. Number cards are valued by their number. "Draw two," "skip," "reverse" and "wild" cards are worth twenty points, and "wild draw four" cards are worth 50 points. The first player to achieve 500 points wins according to the official UNO rules.