Kobayakawa is a microgame consisting of cards numbered 1 to 15, and a bunch of coin tokens. It is played over 7 rounds. At the start of a round, everyone is dealt a card, and one card is revealed at the centre of the table. This is called the Kobayakawa. Beginning with the start player, everyone gets to take one action. You have two choices - either draw a card then discard a card face-up (i.e. an opportunity to change your card in hand), or draw a card from the deck to replace the Kobayakawa (i.e. changing the Kobayakawa value to whatever you draw). Once everyone is done, you take turns deciding whether to bet 1 coin. Finally the players who opt in reveal their cards, and the highest number wins the pool, plus one more coin from the general supply. The twist is this: whoever holds the smallest number gets to add the Kobayakawa value to his card value. This twist is the very soul of the game.
The two face-up stacks at the centre of the table are the discard pile and the Kobayakawa.
I did a 6-player game, which seems to be the ideal number. Despite the simple rules, I find the game very thinky. When a player decides to draw a card, does that mean he has a low card and he's hoping to draw a higher one? When he decides to replace the Kobayakawa, does that mean he has a low or middling card and he's hoping to change the Kobayakawa to a higher number? The current value of the Kobayakawa needs to be considered too. A low number means it won't have a large impact at round end. You will need a high number to win. Maybe not the highest, but something close to the highest. A Kobayakawa value of 2 will let 14 beat 15, if these are the only two numbers opting in. If 12, 14, 15 are in, then 15 still wins because the bonus of 2 goes to 12, which doesn't help it win.
I find that I keep thinking about every move the other players make. Why did she do this? Why did he do that? Now of course some people may play the game very randomly, and may even win. That would make my careful deductions meaningless. The group I played with did not play that way. Everyone put at least some thought into his decisions.
The cards being discarded can be an important source of information too, and not just for card counting purposes (which is important too because it gives you definite information). Someone discarding a high card may be holding another even higher card, or may be holding a middling card and hoping to gain the Kobayakawa bonus. Even how quickly a player decides can give you a hint. A long pause would mean a difficult decision. Then looking at the discarded card may help you guess what the card still in hand is.
There is a poker feel to the game. You can observe the reactions of your opponents to guess their card. How do they react when someone changes the Kobayakawa and gets a larger number? Someone who looks happy might have a small card in hand. During the betting stage, there is also some bluffing. Someone who looks confident may be just trying to scare others into backing off. Someone who looks unsure may be trying to lure others into betting so that he can win more coins.
Turn order can make a big difference. The later you are, the more information you'll have before you need to make your decision, both in deciding your action and later in deciding whether to bet. So it is not surprising that the winner of a round becomes start player for the next round - usually the least favourable position to be in.
Our game was a 6-player game, which is the highest number, so when it came to the betting stage, many cards were already seen. With so few cards remaining in the draw deck, and only 15 cards in the game in the first place, it was easy to count what numbers remained. I tended to be conservative and I counted cards carefully. I ended up rarely betting, and it so happened that when I sat out, it was the right choice. I would have lost my bet had I committed. However, I am not sure I was playing right despite my "correct" decisions. Maybe during the action phase I should have taken the other action? Or maybe during the betting phase I should have bluffed and scared others away? One funny thing in our game was after it ended, we realised we had been playing all this while without the #15 card. It was missing right from the start and no one realised it. That probably distorted our decisions, because most likely someone had suspected that another player was holding the #15 card and thus refrained from betting.
You start with only 4 coins. If you are very unlucky, you'll go bankrupt after four failed bets. There are only 7 rounds in the game.
I like how they stylised the original Japanese name 《小早川》 and turned two of the characters into simple vertical lines.
Kobayakawa is a game of knowing when to strike. It looks nothing like Poker but surprisingly it has a bit of Poker feel. There is luck, and you have limited control, so the key is judging when the right time to gamble is, or creating the right time to gamble by bluffing. There is a lot of guessing what your opponents are thinking. By looking at how much I have written about such a simple game, you can tell I am very intrigued. The depth in this game is not in how complex the calculations are, but in reading your opponents' intentions and playing the psychological game. The number of cards in the game is so low that it's easy to count all cards - what you've seen, who discarded which card. The key is how to make sense of this information. I was quite surprised such a minimalistic game made me think so much. There are some subtleties which are not immediately apparent. It's an ingenious piece of work.