How to play
- Goal
- Shade cells so each outlined room has exactly one false number, dark cells never touch by an edge, and all pale cells stay connected.
- How it ends
- A chart is won when the shading satisfies every rule; there is no loss.
- Record
- Each chart keeps the time of its first solve and the public fastest first solve.
- A number tells you how many edge-adjacent squares are dark. Numbered squares stay pale. Exactly one number in each outlined room must be false, dark squares may never share an edge, and all pale squares must connect through their edges.
- The worked picture is from the real Chart 001. If the top-middle square stayed pale, both nearby numbered runes in the same room would be false. So it must be dark. Continue testing the numbers against the one-lie rule and the dark-neighbour rule.
- Tap a blank square to cycle blank, dark, pale pencil note, then blank. Pencil notes are optional. Undo, Redo and Restart correct marks; Restart keeps the first clock running. A chart finishes when its dark squares satisfy every rule. There is no loss, and replays are untimed practice.
Controls
| Tap / click a mutable square | Cycle blank → dark → pale note → blank |
|---|---|
| Right click / Space | Mark the focused square pale |
| Arrow keys | Move the square focus |
| Enter | Cycle the focused square |
| Backspace | Clear the focused square |
| Z / Shift+Z / Undo / Redo | Reverse or restore a mark |
| Restart / R | Clear this chart while preserving its first clock |
| Escape | Close a panel or return to the atlas |
| Gamepad | Move focus, cycle or mark pale, undo, redo and reach every panel |
All 160 original charts have one independently verified answer and a bounded no-guess deduction trace. Pale pencil notes are optional. Private witnesses do not ship. Saves use morass.usowan.v1; sound follows the shared site setting. No ads or analytics run inside the game.
Watch how to play
About Usowan
In a hall of oathstones, each numbered pale square claims how many of its edge neighbours are dark. One rune lies in every brass outlined rectangular room; the others tell the truth.
Shade your way through 160 original charts. The dark squares cannot touch along an edge, and all pale squares must remain connected. Independent checks prove one solution and a no-guess deduction path for every chart.
Your first solve time stays in this browser. An uninterrupted first finish can claim the named best shown beside the clock and on the chart cards.
