How to play
The board is a grid of magic lanterns, some lit and some dark. Tapping a lantern flips it — lit to dark, dark to lit — and also flips the lanterns directly above, below, left and right of it. Turn every lantern off to clear the puzzle. Each puzzle is built by pressing random lanterns on a dark board, so every one can be solved, and the “Minimum” counter shows the fewest taps that will do it. Pick a board from 3×3 for a warm-up to 7×7 for a real challenge; puzzles are numbered, so each size has its own run to work through.
Hints and records
Stuck? “Hint” lights up one lantern that belongs to a shortest solution from where you are now, and “Show solution” marks all of them. The solver works out the true minimum every time, even on 4×4 and 5×5 boards where several different solutions exist. Your best move count for each puzzle is saved in this browser whenever you clear it without hints. You can use the arrow keys to move between lanterns and Space or Enter to tap.
Tips
Tapping the same lantern twice undoes it, and the order of taps never matters — only which lanterns you tap. A classic method is “chasing the lights”: go row by row from the top, and for every lit lantern tap the one directly below it. That clears all rows except the last; the pattern left there tells you which lanterns in the top row to tap before chasing again. With practice you will start spotting shortcuts that reach the minimum.