Crazy Eights is a shedding-type card game for two to seven players and the best-known American member of the Eights Group which also includes Pig and Spoons. The object of the game is to be the first player to discard all of their cards. The game is similar to Switch and Mau Mau. Originally this was played primarily by children with the leftover cards not used in Euchre. Now a standard 52-card deck is used when there are five or fewer players. When there are more than five players, two decks are shuffled together and all 104 cards are used.

CRAZY 8’s GAME RULES
Set-Up:
Pass out 5 cards face down to all players. The remaining cards are placed in the center of the group. The top card from the center is flipped over and placed next to the pile. If the first card is an 8, the 8 is placed somewhere in the middle of the pile and a new starter card is flipped over.

How to Play:
Players try to get rid of their cards by placing them on top of the flipped-up card in the center. Players may do so if the card they want to get rid of is the same number or suit of the card flipped up. 8s are wild and if a player plays an 8, they must state what suit the 8 will be for the next player. If a player cannot place any of their cards on the one in the center, they must draw
cards from the pile until they can do so or until they’ve drawn a maximum of five cards.

Scoring:
After a player gets rid of all of their cards, the round is over and points are tallied. Cards remaining in players’ hands are counted as the following point values:
Cards 2 through 9 (except the 8) are worth their face value Aces are worth 1 point. Cards 10 through King are worth 10 points. 8s are worth 50 points.
Once a player reaches 100 points or above, the player with the lowest number of points wins the game.

The game first appeared as Eights in the 1930s, and the name Crazy Eights dates to the 1940s, derived from the United States military designation for the discharge of mentally unstable soldiers. It may have derived from the German game of Mau-Mau.

There are many variations of the basic game, under names including Craits, Last Card, Switch, and Black Jack. Bartok, Mao, Taki, and Uno add further elements to the game.

David Parlett describes Crazy Eights as "not so much a game as a basic pattern of play on which a wide variety of changes can be rung," noting that players can easily invent and explore new rules.

Card game historian John McLeod describes Crazy Eights as "one of the easiest games to modify by adding variations", and many variant rules exist. Common rules applied to cards include:

Queens skip
Playing a Queen causes the next player to miss their turn.
Aces reverse direction. Playing an Ace reverses the direction of play.
Draw 2: Playing two forces the next player to draw two cards, unless they can play another two. Multiple twos "stack"; if a two is played in response to a two, the next player must draw four. If the game ends on a special card, that card's rule is not applied.

A popular variant of the game in the United States is Crazy Eights Countdown, where players start with a score of 8. A player's score determines how many cards they are dealt at the start of each round, and which rank of card is wild for them. (So initially, all players are dealt eight cards and 8s are wild for everyone; after one round, one player will be dealt seven cards and 7s will be wild for them, but 8s will be wild for everyone else.) The first player to reduce their score to zero wins the game.