Puzzle Setup

Grid Size

Difficulty

Ready — generate a puzzle to begin.

Live Progress

Bulbs

Lit Cells

Conflicts

Bad Numbers

Click a white cell to place a bulb 💡. Click again to place a mark ✕. Click a third time to clear.
Bulbs illuminate all cells they can see horizontally and vertically until blocked by a black cell.
No two bulbs may illuminate each other — conflict cells turn red.
Numbers on black cells show exactly how many adjacent bulbs must be placed.
Every white cell must be illuminated when solved.

💡 Pack-Verified Grid 10×10 easy — Seed —

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bulb illuminated conflict ✕ mark

Click white cells to cycle: bulb → mark → clear —