Cat in the Box rules




Subjects should be held individually in a box-shaped container that cannot be observed from the outside. Except during the experiment, strictly refrain from keeping multiple individuals in the same space and the fur color of the subject should not be observed or recorded. The furry subject should be a cat. When a subject's fur color is observed by any method such as visual inspection, the fur color which should be absolutely unique causes the quantum convergence. No subject bears a similar physique and fur color. Before starting the experiment, please read this experiment manual carefully to learn how to handle the subject. Good luck on the experiment.

Outline of the Experiment
"Cat in the box" is a card game categorized as a trick-taking game. The color of each cat card is not certain, and when the card is played, it will be treated as the color declared by the player. However, players are not allowed to declare the color of a card with the same number that has already been declared. Follow the rules, and approach the mysterious ecology of... Cats.

1. Components

45 cat cards- 5 cards each from 1 to 9

1 research board

1 experiment result booklet

4 research cards

1 round start player card

5 player boards

60 player tokens, 12 of each color

4 observed tokens

1 rulebook

The components to be used differ according to the number of players. Refer to the table below. 

Table 1-1 Components to be used according to the number of players

Number of players       Cat cards     Player boards    Player tokens Observed tokens

5 players, 45 cards, 5 player boards, 5 types, no observed tokens

4 players, 40 cards, 4 player boards, 4 types of player tokens, observed tokens needed

3 players, 30 cards, 3 player boards, 3 types, no observed tokens

2 players, 25 cards, 2 player boards, 2 types of player tokens, observed tokens needed

2. Game preparation

In this game, players play a number of rounds equal to the number of players, and the sum of those rounds determines the winner of the game.
Before starting the game, follow the procedure as below:


1. Each player should be seated in a position where they cannot see each other's hands.
2. Each player takes a type of player token (all 12 pieces) and a player board.
3. Place one player token on each X on your player board.
4. Insert the research cards into the research board and place it in the center of the table. See the table below to check which face of the research cards to use. Depending on the number of players, observed tokens must be placed on the research board.
5. Write down each player's name on the experiment result booklet (optional).
6. The player who most recently encountered a cat will be the start player. The start player receives the Round Start Player card and puts it in front of them.

This concludes the preparation of the game. Follow the instructions on the next page to start the first round. 

5 players, face of player board 5, face of research card purple, observed tokens not used

4 players, face of player board 4, face of research card white or purple(use white your first game), place on all 4 spaces of 9

3 players, face of player board 3, face of research card white or purple(use white your first game), observation tokens are not used.

2 players, face of player board 2, face of research card white, place on all 4 spaces of 6

When playing with two players, some of the rules are different. See page 10 for more details. 

 2. Round sequence

Each round consists of three phases as below.

1. Preparation phase > 2. Trick phase > 3. Scoring phase

To win this game, a player must have the highest total score after playing rounds equal to the number of players 

1. Preparation phase

Distribute 10 cards when playing 2 to 4 players and 9 cards when playing with 5 players!

[1] Deal player's hand and put 1 card face down
Shuffle all cat cards face down and distribute them to each player evenly. The dealt cards are called your hand. Look at your hand and be careful not to let other players see what is in your hand.
After checking your hand, each player simultaneously selects one card from their hand and places it face down near the research board.

[2] Predict tricks in clockwise order

Don't use the face down cards in the current round

Each player checks their hand and predicts how many tricks they will win in this round. The numbers indicated on your player board shows the number of tricks you can choose for your prediction. Beginning from the start player and then moving clockwise, each player places a player token on the predicted number of tricks they will win on their player board. After all players have made their predictions, proceed to the trick phase. 

If you are playing with 3 players, you can only predict the number of tricks you will win as 1,3,or 4. This means you cannot declare "2 tricks"!

Choose one card from your hand and place it face down near the research board. When playing with 4 players, a total of 4 cards will be removed and these cards will not be used in this round. 

Anne checks her hand and looks at other players' predictions. She predicts that she will win two tricks, and places her token on space "2" on her player board. 

2. Trick phase
In this phase, players will repeat a series of bench scale experiments mini games known as tricks. After playing the specified number of tricks or when a paradox occurs, the trick phase ends and players proceed to scoring phase.
The start player begins by playing a cat card from their hand and all other players in clockwise order do the same. When any player plays a cat card, they must declare the observed color. There are rules when declaring the observed color:
Declaring the observed color
The color of the cat cards in your hand is not certain. When a cat card is played from
any player's hand, that player observes and declares the cat's color as red, blue, yellow, or green, as shown on the research board.
The player who played a cat card declares what color the played card is, places the card alongside that color on their player board, and then places a player token in the corresponding space on the research board.

Led color

During a trick, the first observed and declared color is known as the led color.

Peter played a cat card of the value 5 and declared it "blue". Peter placed the played card beside blue on his player board and placed one of his player tokens on the blue 5 space on the research board. Since Peter is the first player to reveal a card in this trick, "blue" declared by Peter will be the led color for this trick.

Rules on declaring the observed color
To positively declare a valid color, the observed color must satisfy the following rules.
Rule 1: On the row of color you are going to declare on the research board,
the space of the number of the cat card you are playing must be empty.
Rule 2: On your player board, a player token must be placed on the X of the color you are going to declare.

Players must follow the rules above to play a cat card.
In addition, the following rules must be fulfilled depending on the situation.
When playing a card as the start player:
The start player must declare blue, yellow, or green when declaring a color. This means the start player may not declare red (trump). However, if any player token(s) of any player is already placed on the red row on the research board, this rule can be ignored and the start player may declare red as the led color. You can also declare red as the led color if you cannot declare any other color with any cards from your hand.

If you want to win a trick, you should play the same color as the led color (the so-called follow suit rules)

When playing a card after the first card: (+he so-coiled follow l Players who play a card after the start player may declare any color (red, blue, yellow,
or green), as long as it satisfies rule 1 and 2. If you declare a color which differs from the led color, remove the player token on your player board placed on the X space of the led color. If the player token has already been removed, ignore this step.

A color which shows an X on your player board means you cannot play that color any more. This restriction might haunt you quite badly.


In the previous trick, a cat card is observed as "red", thus a player token is placed on the red row of the research board. Therefore, the start player Harry can play a cat card of 8 as the first card of the trick and declare it as "red". 


The start player declares "blue" as the led color. Anne can also declare a "blue" cat card, but she chooses to declare a "red" cat card, thus removing her player token from the "blue" X on her player board. Since her player token on the "blue" X is removed, she cannot declare "blue" for the remaining of this round. 

Winner of the trick
After all players have played a card and declared a color, check who is the winner of the trick.
The player who played the strongest card is the winner of this trick.
The strength of the card depends on the declared card's color, followed by the card's number.
Strength of the color
If all players played and declared a card of the led color, skip checking the strength of the color.
However, if any player declared a color different from the led color, check the strength of the color

Red (trump) is the strongest, then the led color, and the other colors are the weakest.


If red is declared in addition to the led color:

Red (trump) is stronger than the led color. Leave only cards declared as red and remove all other cards when checking the strongest color. 

If blue, yellow, or green is declared in addition to the led color:
he led color is stronger than the other colors. Leave only cards declared as the led color and remove all other cards when checking the strongest color.

After checking the strength of the color, just compare the number of the remaining cards!

Strength of the numbers

Compare the remaining cards. The card with the highest number wins the trick.

Winning a trick

The player who wins the trick takes all the played cards together into a pile and places it face down in front of them.
You can count how many times a player has won this round by counting how many piles of tricks they have in front of them. Make sure to separate each trick so that they do not get mixed up.
The player who wins the trick will be the start player for the next trick and plays the first card.

At this moment, the round start player card does not move! Be careful!


Anne declared "yellow" as the led color.
When checking the strength of the color, Harry loses because he declared "green", and Anne loses because Peter and Erwin declared "red". Peter and Erwin compare the numbers of their "red" cat cards (because they are trump). Peter won by playing the red cat card with the higher number.

End of trick phase and paradox
Repeat playing a trick until there is only one card left in your hand. After that, end the trick phase and proceed to the scoring phase. If a paradox occurs during the trick phase, immediately stop the trick phase and proceed to the scoring phase.

If you're playing with 4 players, play 8 tricks and the round is over!

Occurrence of a paradox

During the trick phase, when you cannot declare and observe any card
from your hand according to the rules, which means, you cannot meet
the observation rules and place a player token on the research board, so a paradox occurs.
A paradox cannot be created on purpose. If there is a card that you can play and declare the observed color, you must play that card. 

If anyone finds out that you could have played a card after you revealed your hand, just play that card and continue this trick!

When a paradox occurs, immediately stop the trick phase.

The player who caused the paradox reveals their hand and declares that a paradox has occurred.
No player wins the trick that caused the paradox, but do not remove the tokens placed on the research board during that trick.


Peter's player tokens on the blue and yellow x of his player board are remove. Therefore, Peter can only declare his cards red or green. The cat cards in Peter's hand are 4 and 6, but all four spaces of 4 and 6 on the red and green row on the research board are filled, which means Peter cannot declare and observe a valid color. In this case a paradox occurs.

Peter reveals his hand and declares that a paradox has occurred. The current trick is interrupted and players after Peter are not allowed to play any more cards. Players who have revealed their cards in this trick before Peter put aside the cards played in this trick. Leave the research board as it was when the paradox occurs.

3. Scoring phase
Record the scores earned by each player on an experiment result sheet.
There are 2 kinds of scores, which are scores from tricks and bonus scores from victory prediction.
Scores from tricks
Each player gains 1 point for each trick won. Count the number of piles in front of you to see how many tricks you have won.
If any player caused a paradox during this round, the player who caused the paradox instead scores -1 point per trick that they have won.
Bonus score from victory prediction
If the number of trick(s) won is as predicted, that player receives a bonus score. If any player caused a paradox during this round, the player who caused the paradox will not receive any bonus score.
From the research board, find the largest group of your player tokens which are adjacent to each other, scoring 1 point for each token in that group.
"Adjacent" refers to a state in which your player tokens are connected vertically or horizontally. Diagonal connection is not considered to be adjacent.

1-2. Preparation phase for the next round
After completing the scoring phase, the next round begins. During the preparation phase after the second round, the following procedure will be added.

• Each player collects their player tokens from the research board and their player board.
• Place one player token on each X on your player board.
• Pass the Round Start Player card to the player to the left of the current Round Start Player.

4. End of the game

The game ends after all players have been the round start player. The winner is the player who scored the most points after adding the scores from each round (refer to the experiment result sheet). If there is a tie, the player with the highest score during the final round wins. If those players are also tied, the tied players share the victory.

5. Additional rules for 2 players

In a 2 player game, even if a paradox does not occur when the round is over, one space remains empty on the research board. This result is expected and is a correct phenomenon.

When playing with 2 players, use the following rules.
1. Preparation phase

• Deal 10 cat cards to each player, and place the remaining 5 cards on the center of the table. After that, reveal 3 cards from the pile and place an unused player token on the green row of the research board for each number revealed. If a duplicate number is revealed, place an unused player token on both the green and yellow rows of that number. If all three cards are the same number, place an unused player token on the green, yellow, and blue rows of that number.
• Do not predict victory in a 2 player game. When the round ends, if any player wins 4 or fewer tricks, that player receives a bonus score.

No other rules are changed in a 2 player game.


Game design: : Muneyuki Yokouchi (Ayatsurare Ningyoukan) 

Artwork: : Osamu Inoue 

Package design: : Tomoyuki Uchikoga, Mizuki Nakajima (CHProduction)

Translation : Chester Lee & Ted Alspach 

DTP: : Osamu Inoue 

Producer Tohco Neijima 

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