Uno rules

Played with its own deck rather than a 52-card one, and probably the most widely sold card game in the world. The mechanic is crazy eights; the deck is what makes it.

The deck

108 cards in four colours — red, yellow, green and blue. Each colour has one zero, two each of one to nine, and two each of skip, reverse and draw two. There are also four wild cards and four wild draw four cards.

The deal

Seven cards each. The rest is the draw pile, and one card is turned face up to start.

Your turn

Play a card matching the top card by colour, by number, or by symbol. Or play a wild. If you cannot play, draw one card — and you may play it immediately if it fits.

The action cards

Skip: the next player loses their turn. Reverse: the direction of play turns around. With two players it acts as a skip. Draw two: the next player draws two and loses their turn. Wild: name any colour to continue in. Wild draw four: name a colour and the next player draws four. Officially you may only play it when you hold no card of the current colour, and a suspicious opponent may challenge you — if they are right you draw four instead.

Saying uno

When you play your second-to-last card you must say uno. If another player catches you before the next player takes their turn, you draw two.

Scoring

The winner scores the cards left in everyone else's hands: number cards face value, action cards 20, wilds 50. First to 500 wins the match.

Uno: an example game

One game of Uno followed from the deal to the finish, move by move, with the reason for each choice.

The deal

Three players sit in this order: you, Ada and Bo. Bo deals seven cards each, turns up red 7 to start the pile, and the player to the dealer's left — you — goes first, with play moving to the left.

Your hand: red 3, green 7, blue skip, yellow 5, yellow draw two, blue 1 and a wild.

The first round of turns

You could play red 3 on colour or green 7 on number. You play red 3, your only red card, while red is the colour in play. Ada plays red skip, which skips Bo and brings the turn back to you.

You have no red, but you can match the skip with your blue skip. That changes the colour to blue and skips Ada. Bo plays blue 9, and you play blue 1.

Drawing, and a reverse

Ada has no blue and no 1, so she draws a card. It is green 1, which matches the number, and she may play it straight away — so she does. The colour is green.

Bo plays green reverse. With three players, reversing sends the turn back the other way, so it goes from Bo to Ada instead of to you. Ada plays green 4, and then it is your turn.

A draw two, and down to one card

You play green 7, and Bo changes the colour with yellow 7. Ada plays yellow 2. You play yellow draw two: Bo, next in the reversed direction, draws two cards and misses his turn. Ada plays yellow 9.

You play yellow 5 and say uno as you put it down, because it leaves you with one card — the wild. Had you forgotten, either of the others could have caught you before Bo's turn and made you draw two. Bo plays yellow 8.

The challenge

Ada, keen to stop you, plays a wild draw four and names red. That card is only allowed when the player holds no card of the colour in play, and the colour was yellow. You challenge. Ada was holding a yellow card, so the challenge succeeds: Ada draws the four cards instead, and you take your turn as normal.

Had Ada really held no yellow, the challenge would have cost you six cards. You play your wild, name any colour, and you are out.

Scoring the hand

You score what the others are left holding. Ada has red 8 (8), red draw two (20), green 0 (0), yellow 3 (3), red skip (20) and green 5 (5), for 56. Bo has red 9 (9), a wild (50), blue 6 (6), green 2 (2) and red 4 (4), for 71.

That is 127 points to you from one hand. The next hand is dealt a few seconds later, and the match goes on until somebody reaches 500.