About Pairs Nurikabe
Pair the numbered stones and grow their islands through a dark river. Each island holds exactly two stones, and its area equals their sum.
Work through 5 compact charts on a brass-edged survey folio. A promising pairing can force an awkward shoreline: leave room for the river to stay connected.
How to play
- Goal
- Form islands containing exactly two numbered stones each, with area equal to their sum, surrounded by one connected river without a 2×2 pool.
- How it ends
- A chart is solved when every cell is decided and every island and river rule holds; there is no loss state.
- Record
- The fastest first solve of each chart is kept with its holder’s name.
- Mark every cell as land or river. Numbered stones always stay on land.
- Each island is an edge-connected group of land cells containing exactly two numbered stones. Its area, counting the stones, must equal their sum. Stones marked 1 and 2 need an island of 3 cells.
- Separate islands cannot share an edge, but may touch diagonally. All river cells must connect through shared edges, and no 2×2 square may be entirely river. Branches and dead ends are allowed.
- Select River, Land or Erase, then tap cells or drag a stroke. Undo reverses a whole stroke. A cancelled stroke leaves the board as it was.
- A solved chart stays complete until Replay or a confirmed Restart begins practice. Only an uninterrupted first session can set its first-solve time; reopening an unfinished chart is practice.
Controls
| Input | Action |
|---|---|
| Tap / click a cell | Apply the selected tool |
| Drag across cells | Paint one stroke; release to commit |
| Arrow keys | Move the cell cursor |
| Space / Enter / X | Mark river / land / erase |
| Z | Undo one stroke |
| Escape | Close a panel or return to the charts |
| Gamepad d-pad / A / X / Y | Move / river or confirm / land / erase |
| Gamepad LB / B / Start / Back | Undo / back / move between board and controls / Rules |
Tips
- Count the whole island Both stones count toward their combined area.
- Leave a river route A locally plausible island can block the river elsewhere.
- Reconsider partners Nearby stones are candidates, not an instruction to join them.
Good to know
Progress saves in this browser. Reopening an unfinished chart forfeits ranked timing. Music and effects follow the shared site settings; reduced motion has its own toggle.
