How to play
- Goal
- Light every open cell with lanterns while no two lanterns see each other and every numbered wall touches exactly its stated number.
- How it ends
- A chart is solved when all open cells are lit and both lantern and wall rules agree; there is no loss state.
- Record
- The fastest first solve of each chart is kept as a public record, with its holder's name.
- Tap an open pane to place or lift a lantern. A lantern lights its own pane and every open pane it sees along its row and column, stopping at walls. Lanterns must never see one another.
- A numbered wall counts only lanterns directly above, below, left and right. The worked picture shows a wall stopping a beam and counting its adjacent lantern. Warm panes are lit; cool panes still need light. Red walls or lanterns need correcting.
- Leave unused panes blank; no X marks or Check button are needed. Undo restores a lantern, and Restart clears the chart while its first-opening clock keeps running. A replay is untimed practice. Returning from the chart list in the same page keeps the running clock and record chance. Reloading an unfinished chart preserves it locally, without a public record.
Controls
| Tap / click an open pane | Place or lift one lantern |
|---|---|
| Tap / click a wall | Show the panes beside that wall and its current count |
| Arrow keys | Move focus through the chart |
| Space / Enter | Toggle the focused open pane |
| Undo / Z | Restore the previous lantern layout |
| Restart | Clear all lanterns without resetting the first clock |
| Escape | Close a panel or return to the atlas |
Every fixed chart has one independently verified answer and can be solved by elementary forced deductions. At least one numbered clue is necessary on each chart. Private witnesses do not ship. Saves use morass.light-up.v1; sound follows the shared site setting. No ads or analytics run inside the game.
About Light Up
In an Orenvalt ward hall after dusk, place brass lanterns among slate walls. Their warm beams cross each open row and column until stone stops them.
Explore 160 original charts across four open shelves. Every chart has one independently proved answer and can be completed through forced deductions.
Your first finish time stays in this browser. An uninterrupted first solve can claim the named public best shown on its chart card.
