Digit Code

For some unknown reason, we now find ourselves in a situation where we must quickly interpret a six-digit digital code. We will analyse this code by gathering various uncertain pieces of information. Its meaning will become clear in our hands, just as it always has.

In a two-player game, each player creates a secret six-digit code with three numbers above three numbers, in which each digit 0-9 appears at most twice and not next to each other. The letters AY are used to indicate number segments in a column or in a row, or within a particular digit. The players take turns asking each other questions of the following four types:

• How many spaces in the row or column are filled in?
• Is the number even or odd?
• Looking at the adjacent numbers ? and ??, which is the larger?
• Is the segment in row ? and column ? filled in?

Each player must ask all four types of question before they can repeat a type. On a turn, a player may give a six-digit number instead of asking a question. If they have guessed all six numbers correctly, they win; if not, the opponent says “Wrong” and the game continues. A player who guesses wrong twice loses.

With three or more players, one player makes a six-digit number that the other players compete to be the first to deduce, asking questions in turn. Again, a player who guesses wrong twice is out of the game.