How to play
- Goal
- Fill every cell with night or dawn glass so the longest runs match the clues on all four sides.
- How it ends
- A chart is solved when every cell is filled and every longest-run clue agrees; there is no loss state.
- Record
- The fastest first solve of each chart is kept as a public record, with its holder's name.
- Fill every cell with night or dawn glass so the longest runs match the clues on all four sides. Night clues sit at the left and top; dawn clues sit at the right and bottom. A zero means that colour is absent. The worked glass strip shows a night run of three forced by the left clue while the dawn run remains one.
- Tap a pane to cycle unmarked, night, dawn and back to unmarked. Drag across panes to paint the first pane’s new colour as one stroke. Set night, Set dawn and Clear pane act on the outlined pane. Red edge clues cannot be met with the current panes; glowing clues are complete.
- Undo reverses a stroke. Restart clears the panes but keeps the original clock running. A window completes when every pane has a colour and every edge clue agrees; there is no loss.
Controls
| Tap / click a pane | Cycle unmarked → night → dawn → unmarked |
|---|---|
| Drag across panes | Paint the first pane’s new colour as one undoable stroke |
| Right click | Cycle a pane backward |
| Set night / Set dawn / Clear pane | Change the outlined pane |
| Arrow keys | Move focus through the window |
| 1 / 2 / 0 | Set night / set dawn / clear the focused pane |
| Space / Enter | Cycle the focused pane |
| Backspace / Delete | Clear the focused pane |
| Z | Undo the last stroke |
| Escape | Close a panel or return to the atlas |
All 180 charts have stable IDs, exactly one independently verified answer, and both clue families are necessary. The private answer witnesses do not ship. First-solve progress uses the morass.ebony-and-ivory.v1 namespace; sound follows the shared site setting. No ads or analytics run inside the game.
About Ebony & Ivory
In a fantasy glazier’s workshop, each window holds dark night glass and warm dawn glass. Brass edge plaques describe the longest unbroken run of each colour in every row and column.
Explore 180 original windows, forty-five each from 5×5 through 8×8. Every chart has one independently proved answer, and both night and dawn clues matter.
The clock starts when a window opens. Your first solve stays in this browser; an uninterrupted first solve can set the verified public best shown beside the clock and on its atlas card.
