How to play
- Goal
- Fill every ivory tile with a number from 1 to 9 so each tile equals the sum of its absolute differences from its edge-sharing neighbours.
- How it ends
- A chart clears when every tile, including given tiles, satisfies that rule; there is no loss.
- Record
- Only the fastest first solve of each chart is kept; replays are practice.
- Fill every ivory tile with a number from 1 to 9. For each tile, add the absolute difference between its number and each ivory tile sharing an edge. The sum must equal the number you started from. Holes and diagonal tiles do not count; gold given tiles must satisfy their own sums too.
- In the worked three-tile line, the gold 4 has a 2 on one side and an empty tile on the other. Enter 2 at the empty end: each end equals its one difference of 2, and the middle 4 equals 2 + 2.
- Select a tile to highlight its neighbours and read its live equation. Tap a number or press 1–9 to enter it; tap the same number again to erase. Undo, Redo and Restart let you revise entries. A chart clears as soon as every tile is filled and every equation agrees.
Controls
| Tap / click an ivory tile | Select and inspect its edge neighbours |
|---|---|
| Tap a digit 1–9 | Enter it in the selected tile; tap the same digit to clear |
| Arrow keys | Move the tile focus across holes |
| 1–9 / Backspace | Enter or erase a number |
| Ctrl/Cmd+Z / Shift+Ctrl/Cmd+Z | Undo or redo a number |
| Restart / R | Clear this chart while preserving the first clock |
| Escape | Close a panel or return to the atlas |
| Gamepad | Move a visible cursor, choose digits, erase, undo, redo and reach every panel |
All four shelves are open. The first clock starts when a chart opens and never pauses. Restart clears numbers without resetting it; a replay cannot improve the saved first time. Wrong entries remain editable. The released answers stay outside the browser bundle.
About Bosanowa
In an Orenvalt observatory, ivory number tablets form uneven constellations on a dark lapis chart. Brass links reveal the neighbours whose differences each star must count.
Explore 160 original charts across four open shelves. Every released chart has one independently verified answer and can be completed by local deductions without guessing.
Your first solve time stays in this browser. An uninterrupted first finish can claim the named best beside the clock and on the chart card.
