Koi-Koi - Rules

TODO:

• [ ] add exhaustive redraw rules
• [ ] add instant win rules
• [ ] call out yaku house rules

Intro

Fun fact: did you know that the first thing nintendo made was a deck of hanafuda cards?

--==={ sources: fudawiki.org, wikipedia.org }===--

Koi-Koi is a 2 player game played with hanafuda cards.

hanafuda Cards feature 12 sets of 4 cards, 1 set for each month.

players take turns playing cards from their hand to the table, and collecting cards from the table. when specific sets of cards are collected by a single player, they form Yaku, which earn the player points. whenever you earn points, you can either collect those points and end the current round, or choose to continue playing (called Koi-Koi - which means "Come on, Come on!").

There are many, many house rules to Koi-Koi - the game has many variations. This guide will not cover all of them.

Pregame

1. randomly draw 1 card each. whoever draws the earliest card is is the first Oya, or dealer. they also play first on the first round (after that, whoever wins each round plays first the next round).

2. decide how many rounds you want to play:

   • a season (3 rounds),
   • a half year (6 rounds),
   • or a full year (12 rounds).

Playing a Round

1: deal cards.

1. the dealer shuffles the deck. their opponent cuts the deck.

2. the dealer hands out 8 cards to themselves, the other player, and the table. the rest of the cards are stacked face-down in a deck next to the table's 8 cards.

   • do not let your opponent see your cards!
   • the table cards should be are-face up.

2: play a card from your hard.

the player whose turn it is (for first round, start with Oya) chooses a card from their hand to play on the table.

• if the card you play is from the same month as another card on the table, you must play the card from your hand on the matching table card.

  • if there is more than 1 card on the table matching the played month, you may choose which table card to play on top of.

• if the card you play has no card from the same month on the table, you must place your card on the table and leave it there.

  • this card becomes a table card and you or your opponent can play on top of it in a future play.

3. check for completed Yaku.

• when you collect enough cards of a certain type, you complete a Yaku. the rules surrounding certain Yaku can vary widely. i'm familiar with the nintendo ruleset.

• if you have completed a Yaku, you may choose to either:

  • collect the points you have earned so far and end the round, or
  • Koi-Koi, and continue playing.

    • if you Koi-Koi, you do not collect any points right now.

    • the next time you or your opponent form a Yaku, they will be faced with the same decision - end the round, or Koi-Koi.

    • this means that if you Koi-Koi, you are risking the points you could earn right now for the chance to earn more later. this is gambling.

• if you chose to collect your points, end the round and start a new round. else, continue the game.

4. play a card (again), but this time from the table's deck.

the player who just played a card now draws a card from the face-down table deck.

• you must play this card onto the table, the same way you play cards from your hand.
• this card cannot go into your hand.
• remember: if previously on this turn, when playing the card from your hand, you placed your card on the table, that card is now treated as a regular table card.
  • that means that if the card you pulled from the deck is the same month as the card you just placed on the table, you may play the drawn card onto it and collect both.

5. check for completed Yaku (again).

once again, if you score a Yaku, you can choose to end the round or Koi-Koi.

6. swap turns and repeat.

the round ends when someone decides to collect their points instead of Koi-Koi.

Winning

run the game for however many rounds you decided previously. whoever has the most points at the end wins.