The "Turing Machine" board game, designed by Fabien Gridel & Yoann Levet, is a numerical code deduction game in which a fixed set of criteria is used to encode the solution. These solutions, paired with the designated criteria cards, form the structure of a single Puzzle.

For every puzzle: There are 4-6 Criteria Cards selected from the following Google Docs list: (https://docs.google.com/spreadsheets/d/1dfX8t721TQ8SkYII1OoLZE88pM3_lsMlJyGCVeVRp3c/edit?usp=sharing) The rulebook for the Original Game can be found here: (https://cdn.1j1ju.com/medias/a6/12/e4-turing-machine-rulebook.pdf) An additional Page that is not included in the Rulebook can be found here: (https://turingmachine.info/files/rules/TuringMachine_The_X_Paradox_EN.pdf)

There are 3 different variations on the game: Classic Mode, Extreme Mode, and Nightmare Mode. Classic Mode is the standard way to play the game, and the other two are simply more difficult variations on Classic Mode.

The goal of the game in all modes is to query the Machine's various sections' Criteria Cards using sets of Punch-Cards to verify criteria against a particular section's Verifier Card; Essentially, these Verifier Cards are just pre-calculated constructs that reveal analog representations of the result specified by the Puzzle's Criteria Tests. It is most useful to first examine the Criteria Cards and how they function:

On Easy Difficulty, there are 4 Criteria Cards assigned to the Turing Machine by letter. In Standard Difficulty, there are 5 Cards, and in Hard Difficulty, there are 6. Every Criteria Card contains 2 or more "Tests," or statements which would define the behavior of the Target Code in Question; However, there is something that must be understood about the Criteria Cards to begin manifesting a valid strategy for the Game: The Criteria Cards contain a collection of multiple Tests, but for a given Puzzle, only one of those tests is relevant to the construction of the Target Code.

For example: Criteria Card 1: Blue == 1; | Blue > 1;

(For reference, 'Blue' is the digit in the Hundreds place, 'Yellow' is the digit in the Tens place, and 'Purple' is the digit in the Ones place.)

Now, both of the tests on Criteria Card 1 cannot be true at the same time; They are mutually exclusive criteria. Only one of the tests matches the behavior of the Target Code. This is an easy conclusion to make for this card, as well as all of the Criteria Cards up to Criteria Card 25.

However, Criteria Cards 26-48 contain at least 3 tests on them, and the problem arises in the deduction process: More than one test on a Criteria Card between 26-48 can match the behavior of the Target Code; But, remember the rule from before: Only one of the tests on a specific Criteria Card in a given Puzzle is relevant to the construction of the Target Code.

So, what does this mean?

For example: Criteria Card 26: Blue < 3; | Yellow < 3; | Purple < 3;

Let's say that the solution for the Puzzle that contains this Criteria Card is '125'. Notice how both Blue and Yellow are less than 3. Since the Puzzle has assigned only one of this Criteria Card's Tests as the only one which is relevant, using the query '224' against this Card's Verifier would reveal a Check. This might lead you to believe that both the Blue and Yellow digits should be deduced as being less than 3; However, this is not the correct conclusion: One of the Tests isn't being checked for, while the other one is; The player has to find out which one is actually yielding a Check (in this case, it's either the Blue < 3 test OR the Yellow < 3 test).

Easy Difficulty contains puzzles with 4 Criteria Cards, and of the cards are between 1-25. Standard Difficulty contains 5 of those same cards. Hard Difficulty Puzzles contain at least 3 Criteria Cards from the range of 26-48, and the other half of the cards are selected from the entire remaining stack of Criteria Cards 1-48 (all of them).

Two principles guide the generation of a valid Puzzle for this Game: I. No Test shall render any of the other Tests in the Puzzle superfluous; Every single Test in the Puzzle is needed to uniquely identify the Target Code. II. Only One Target Code can match all of the set Criteria Tests for any given Puzzle; If there are multiple solutions to a Puzzle, the Puzzle is invalid.

Extreme Mode assigns a pair of two Criteria Cards per single section on the Turing Machine (4-6 pairs of cards from the entire stack), which can actually be interpreted as having 4-6 cards with extra Tests on them, as that is how they act; Still, only one single Test from a given pair of Criteria Cards is actually relevant to the construction of the Target Code. Nightmare Mode takes advantage of the pre-calculated Verifier Cards by shuffling them, so that the player does not know which designated Verifier Cards are paired with the given set of the Criteria Cards (It's still a 1:1 relationship between the Criteria Cards and the Verifier Cards, it's just that the individual connections are not revealed). This mode also has between 4-6 Criteria Cards from the entire available stack.