A new hidden rule every day
Rulezzle is a free daily number puzzle. Enter a number, study the output, and use what you learn to reach the target in ten guesses or fewer.
Rules use approachable arithmetic and digit patterns. The target and hidden rule are the same for everyone each day, and a hint is always available if you need one.
When does the puzzle change?
A new Rulezzle begins at midnight UTC. Your guesses are saved only in your browser so a refresh does not erase your progress.
Free to play
Rulezzle is free to play and does not require an account.