MOON Rulebook

Table of Contents

Table of Contents

• Set Up a Game
• Counting in Binary
• Cooperative Mode
• Operations
• Difficulty
• Events
• Competitive Mode
• Hackers
• Extra Bits

Set Up a Game

1. Place the 4 CPU registers (A, B, C, and D) and their corresponding switched-off bits in the middle of the table. This will be the central board.

2. Place the operation cards on the left of the central board, sorted by their energy usage: first those requiring 2 energy units (INC, DEC), then those requiring 1 energy unit (NOT, ROL, ROR, MOV), and finally those requiring 1/2 energy units (OR, AND, XOR).

3. Shuffle the goal cards and place the deck face-down on the right side of the central board. These cards represent the calculations astronauts need to make to land on the moon.

4. Take 3 energy units and place them next to you.

MOON simulates a real computer. Operations modify data in the same way as in real microprocessors. So, let's review how to count in binary before you start playing.

Counting in Binary

Both the individual RAM modules and the CPU registers have several bits that work as binary counters. Each position has an associated number (1, 2, 4 and 8 in 4-bit registers).

If all the bits of a register are switched off, the value zero is stored.

If there are any switched-on bits, you have to add the numbers placed on the top of the CPU. This will be the value stored in that register.

For example, this combination represents the number 3 because the bits in positions 1 and 2 are switched on, so 1 + 2 = 3.

This represents the number 9 because the bits in positions 1 and 8 are switched on, so 1 + 8 = 9.

Cooperative Mode

Prepare the game as explained above. For the first game, we recommend to use 3 energy units per round and not to use OR, AND, and XOR operations. Later, you can adjust the difficulty of the game to your level.

To win the game, you must help the astronauts fulfill their mission by solving all the goal cards. Each goal card shows a combination of bits. To solve the goal card, you must store that combination of bits in register A of the CPU.

At the beginning of the game, flip the first three goal cards and copy them in registers B, C and D. Once they are properly placed, discard these 3 goal cards.

Then, flip the top card in the stack of goal cards, and place it face-up next to the stack.

In each round, you can perform as many operations as you wish depending on the energy units available (remember that there are operations such as OR that require 1/2 energy units, while others like INC require 2 energy units).

You are not required to spend all energy units in one round, but you cannot save energy for the next round.

Use your energy units to perform operations on registers A, B, C and D of the CPU and achieve the goal. Remember that a goal card will not be solved until its value is stored in register A of the CPU.

Whether you have resolved the goal card or not, at the end of the round, you have to move the unsolved goal cards up one position, take the top card in the stack of goal cards, and place it face-down next to the stack:

This is when you will recover all the energy you had at the beginning of the round.

If a goal card advances to 5th position at the end of the round, you are a slow CPU, the game is over and the lunar mission failed.

This can happen even if there are no goal cards left in the stack but it takes you more than 5 rounds to solve the last goal cards.

In other words, at the end of the round the goal cards move up regardless of the number of cards left in the stack.

On the other hand, if you manage to solve all the goals of the stack promptly, astronauts will be able to land into the moon safely and you win!

Moreover, there are goal cards that don't have a combination of bits but a bug.

These special cards cannot be discarded and they will block one of the positions of the list of pending goals for the rest of the game.

Operations

During the game, you will need to modify the bits of the CPU registers to reach a goal specified in a goal card. You will do this by using certain CPU operations: INC, DEC, ROL, ROR, MOV, NOT, OR, AND and XOR.

INC — This operation is used on 1 register and costs 2 energy units. It adds 1 to the total value stored in the register.

If the register stores the maximum value (all bits switched on), an overflow happens and the register is reset to zero.

DEC — This operation is used on 1 register and costs 2 energy units. It subtracts 1 to the total value stored in the register.

If all the bits of the register are switched off, subtracting 1 will cause an underflow that sets all the bits of the register to one (switched on).

ROL — This operation is used on 1 register and costs 1 energy unit. It involves shifting every bit on the register to the left and placing the remaining bit on the left in the rightmost position.

In many cases, it is equivalent to multiplying the value of the register by 2.

ROR — This operation is used on 1 register and costs 1 energy unit. It involves shifting every bit on the register to the right and placing the remaining bit on the right in the leftmost position.

In many cases, it is equivalent to dividing the value of the register by 2.

MOV — This operation is used on 2 registers or 1 register and a RAM module and costs 1 energy unit (1/2 in competitive mode).

It copies all bits from one register to another, overwriting the value stored in the destination (it can be useful to copy a value into your RAM module and then recover it later to prevent other players from modifying it).

NOT — This operation is used on 1 register and costs 1 energy unit.

It negates every bit on the register: switched-on bits are switched off, and switched-off bits are switched on. This involves flipping all the bits of the register.

OR — This operation is used on 2 registers and costs 1/2 energy unit.

It copies only the switched-on bits from one register to another.

AND — This operation is used on 2 registers and costs 1/2 energy unit.

It copies only the switched-off bits from one register to another.

XOR — This operation is used on 2 registers and costs 1/2 energy unit.

It copies only the switched-on bits from one register to another, but if the bit was already on, it's turned off.

Difficulty

You can adapt the difficulty of the game in several ways:

1. Changing the number of energy units available per round. We suggest you use 3 units of energy (easy) for the first games and then reduce it progressively (normal: 2.5; hard: 2; master: 1.5).

2. Changing the number of "bug" cards the goal cards deck will have (easy: none; normal: 1; hard: 2; master: 2).

3. Changing the initial state of the registers. For an easy difficulty, take the first 3 goal cards of the deck at the start of the game, and copy their values into registers B, C and D (these three cards can then be considered solved). For normal difficulty, do the same with the first 2 goal cards and registers B and C. For hard difficulty, the first goal card is copied to register B. For master difficulty, register A is set to value 1 and the rest of registers are set to 0.

4. Adding event cards to the goal cards deck.

Events

Add event cards to the deck of goal cards to make the games more exciting:

RESET cards reset a register (all its bits are switched off).

ERROR register cards disable the register.

ERROR operation cards disable the operation.

OK cards repair an existing ERROR in a register or operation (you cannot keep them around to repair future errors).

Competitive Mode

Before playing in competitive mode, it's a good idea to have played in collaborative mode first. Review the previous sections to learn the basics of the game.

Prepare the game as explained in Set Up a Game. Each player chooses a color, takes the RAM card of that color and sets all the positions of their RAM module to zero. Distribute the energy units to each player according to the game's desired difficulty: 4 for easy, 3 for normal, 2.5 for difficult, and 2 for master.

Shuffle the goal cards and place them face-down to the right of the CPU. Each player takes a goal card from the deck, looks at it (without showing it to the other players) and places it face-down next to their RAM module.

In each turn, each player may play as many operation cards as allowed by their energy units. A player is not required to use all their energy units. Energy units cannot be transferred from one player to another.

Any player can modify the values of any of the bits in the 4 registers of the CPU in their turn, but will not be able to copy or modify the values stored in the RAM of other players.

If a player manages to store their goal in register A of the CPU during their turn, the player will show their goal card to the rest of the players, keep it next to their RAM module and take another goal card from the deck.

Once the deck of goal cards is exhausted, the player who has solved the most goal cards will be the winner.

In competitive mode, there are two additional changes with respect to the cooperative mode:

1. The MOV operation requires 1/2 energy unit (instead of 1 energy unit).

2. Bug cards are used to view another player's goal card at any time during the game. When a player takes this card from the deck, they show it to the other players and saves it for later use. The bug card can only be used during the player's turn and, when used, the player who was forced to show their goal card will take possession of the bug card, which they can then use during one of their turns. These cards do not count as a solved goal to decide the winner at the end of the game.

Hackers

You can also make each player have special features in the competitive games. Look at the back of the RAM cards to see which hacker you want to be:

Green: you can use INC or DEC by consuming only 1 energy unit.

Yellow: you can use ROL or ROR consuming only 1/2 energy units.

Purple: you can make 2 MOV operations without consuming energy on each turn.

Red: you can do 2 logic operations OR, AND, XOR without consuming energy on each turn.

Extra Bits

MOON's modular design allows you to expand the number of bits in its CPU, substantially increasing the complexity of the game.

The base game comes with 8 extra bits to extend the registers A, B, C and D to 5 bits or 6 bits.

Since goal cards only contain 4-bit combinations, we will need two goal cards to indicate the 5-bit or 6-bit combinations to be solved.

In cooperative mode, we will draw two goal cards when solving a goal:

• You solve a goal.
• You show the following goal.
• At the end of the round, you draw one goal card.

The goal will be made up of all the rightmost bits of the two goal cards. For example, playing with registers of 6 bits, the goal will comprise the 4 bits of the card on the right and the 2 rightmost bits of the card on the left.

In competitive mode, you will put each part of the goal to each side of your RAM module to avoid mixing them.