top of page

Cat in the Box

This isn’t the first game inspired by Schroedinger’s Cat, the thought experiment postulated by Austrian physicist Erwin Schroedinger to demonstrate the notion in quantum mechanics that matter can exist in multiple states at the same time with the actual state only determined at the point of observation. As an example, we reviewed Dead Cat (He Does Not Throw Dice) four years ago on Board’s Eye View. Muneyuki Yokouchi’s Cat in the Box is perhaps the cleverest evocation yet of Schroedinger’s thought experiment – tho’, title notwithstanding, neither the cat nor the box actually feature in this essentially abstract card game.

Cat in the Box is a trick-taking card game for 2–5 players played with a deck of 45 cards: five each numbered 1–9, tho’ you take out some numbered cards if you have fewer than five players. Players are each dealt a hand of nine or ten cards, depending on the number of players. You choose one card from your hand to discard face down and take out of play. Over the course of the round, you’ll be playing all but one of the cards in your hand as in a conventional trick-taking card game.

So far, so routine. However, the quantum trick in this trick-taking game is that all the cards in your hand are the same colour (black). It is only when you play them that they take on one of the game’s four suits (colours). When you lead, you declare the colour of the card and you mark that number and colour on a grid. That card cannot now be duplicated. Players must follow suit (again, marking the numbers and colour on the grid) unless they declare that they have no cards of that colour. When they do this, they cannot subsequently declare any of their remaining cards to be of the colour they indicated they did not have.

Why might you not follow suit? Prior to the start of each round, players must predict how many tricks they will win (1, 2 or 3 in a four- or five-player game; 1,3 or 4 in the two- or three-player game). At the end of the round, you’ll ordinarily score a point for each trick you win but you will also score a bonus if you precisely hit your prediction. The bonus is your longest orthogonally adjacent run on the grid…

You can see then that it can often be worthwhile declaring a colour that doesn’t follow suit if it helps you both to hit your prediction and contribute to a high-scoring bonus run. Remember too that numbers already taken in the grid cannot be duplicated, so there will almost certainly be circumstances when you simply cannot follow suit because you don’t have a number in that colour that hasn’t already been played.

And with five of each number and only four suits, you could well find yourself stuck with cards in your hand that you simply cannot play because those numbers have already been played in all four colours. When you are in this position for other than the last card in your hand, you create a quantum paradox. In that situation, the round immediately ends, the current trick is abandoned (it doesn’t score) but other players score for their tricks in the usual way. The player who created the paradox, however, scores a negative point for the tricks they have won, and they don’t score a bonus even if they correctly predicted the number of tricks won.

As you play a round for each player, the length of the game depends on the number of players. Our Board’s Eye View plays varied from around 20 minutes with two or three players to around 40 minutes with four or five. There are some rule modifications needed for the two-player game and, for us, Cat in the Box is at its best with four or five players – tho’ you need to play your cards right because with higher player counts we found rounds ended with a last or penultimate trick paradox more often than not.

Shown here on Board’s Eye View is the deluxe version of the game from Bézier with attractive plastic tokens to place into the slots in the customised dual-layer grid board. Art is by Osamu Inoue. Our one gripe is the usual one for games with black cards with printing that bleeds to the edge: they’re inevitably very prone to showing marks or nicks. This is a game where we’d certainly advise sleeving the cards before playing. With that prophylactic measure in place, however, Cat in the Box could be the best trick-taking game published to date. Better trick-taking games may or may not exist but, if we’ve learned anything from Professor Schroedinger’s thought experiment, we won’t of course know until we’ve observed them :-)

(Review by Selwyn Ward)

6,821 views0 comments

Recent Posts

See All




bottom of page