Koi-Koi is a Japanese card game using a traditional 48-card Hanafuda deck.
Hanafuda literally means “flower cards.” In the deck there are twelve suits representing the twelve months of the year. Each is designated by a Japanese flower or plant, and each suit has four cards.
Each suit contains a combination of regular cards and special cards, which vary from suit to suit.
The four types of cards found in the deck are:
Brights, Animals, Ribbons and Plain
In addition to these types there is a special card "The Sake Cup" that does not fit into any of the above categories.
The goal of Koi-Koi is to earn points by making sets, or “yaku,” as fast as you can and ending the round before your opponent. A full game session is 12 rounds or “months,” and the player with the most points after 12 rounds is the winner. Each round is winner-take-all and can involve score multipliers.
In the first round of the game, player 1 is designated as the dealer. In later rounds, the dealer is selected by who won the previous round. The dealer has certain advantages in the game, including breaking tied scores.
Each player is given 8 cards, 8 additional cards add placed on the board.
The idea of the game is to create sets (Yaku) from cards you match.
Each turn a player needs to do at least 2 things.
After doing these two actions, your turn is over. At this point there are two possible next steps
Koi-koi - If you choose Koi-koi, the round continues. Note that there are risks in doing this which will be explained in the scoring section.
Shōbu - If you choose this option, the round ends and you will be awarded points for the round.
Scoring occurs after a player has elected to end the round, or after both players have run out of cards in their hand.
If a player has elected to end the round, this player will receive points for the round, the opponent receives no points, even if they have created Yaku in the round.
If the round ends because both players have run out of cards, then points are awarded to the player with the highest scoring Yaku in the round.
If the round ends because both players have run out of cards and both players have scored the same number of Yaku points, then the dealer advantage is invoked and the dealer will automatically receive 6 points, the opponent receives no points.
There are a few factors that affect your score for the round.