This is one of the first games available for the Fred project, as the first version was programmed by Jospeh Weisbecker on the 7th december 1971.

The first "Deduce" is not really a game but rather a demonstration of "artificial intelligence" of the computer. It works like this: the computer deduces which one of 8 front panel lights the player has chosen, simply by asking three questions. These questions are in fact a serie of 4 front panel lights lit, and the player must tell the computer if his chosen light is among the ones lit.

There is no screen display involved in this version. Everything is happening on the front panel lights of the Fred computer.

Sometimes later, surely after 1972 (as the famous board game Mastermind was released in 1971/1972), a second version was programmed for the Fred systems. This time it plays more like a Mastermind game where the player must guess 4 digits chosen by the computer within 15 rounds.

Each time the player enter a serie of 4 digits, the computer will tell how many digits are are their right position, and how many digits are valid but misplaced.

At the end of the 15 turns, if the player didn't succeed in finding the right 4 digits code, the computer will display LOSE.