THE FIELD NOTES

How to play Code Breaker

1. Read every clue and check the available digits and code length. A clue may constrain a position, an order, or a relationship between digits.
2. Build a code using each available digit at most once. Zero may appear first, so treat the answer as a sequence rather than an ordinary number.
3. Check the entire code against all clues before submitting. The puzzle is generated to have one solution.

A worked example

With digits 1, 2 and 4, a two-digit code whose digits add to five and whose first digit is smaller than its second is 14. The code 41 has the same sum but fails the order clue.

A strategy to try

Start with the most restrictive clue. Eliminate candidates as you go, then use the remaining clues to test the few combinations left.

Choose your challenge

Five levels change the code challenge. Try the control demo on the ready screen if arranging digits is unfamiliar, then start untimed before adding the clock.

Each round has ten questions. Choose a 90-second sprint or untimed practice. Correct answers earn 100 points; finishing a sprint adds up to 99 time-bonus points. A score describes this round, not intelligence or a medical assessment.

Full rules and scoring · Play a live round with friends