LADDER

How to play

Every number is how many steps it is to the nearest well.

A well is a hole, not a number, and it is drawn — some are printed for you and the rest are yours to find. Steps go up, down, left and right, never diagonally. Tap a blank square, then tap a digit or the well key.

• Neighbouring numbers can differ by at most 1.
• Every 1 touches a well; every bigger number touches one exactly one smaller.
• Nothing needs guessing. Every square can be worked out.

What the number means

A board's depth is how many of its squares cannot be found without the hardest inference in the game.

Measured by the same solver that builds the puzzles, not guessed at — and every rung here is deeper than the one below it.

• You get 3 slips a rung, two fewer than the daily: with five, a lucky guesser clears a board they cannot reason about.
• The run ends the moment a rung stops you. That ending is what produces the number.
• Clear depth 12 and fail depth 16 and your line is between the two. You are shown both ends, never the middle, because the middle is a number nobody measured.
• Fall at the first rung, or clear all seven, and it says so rather than inventing a figure.

One run places you between two rungs. Run it again and it may land a rung either way.

Kept on this device. Nothing is sent anywhere and there is nobody to tell.