Lamps

What is Lamps?

Lamps is a quiet logic puzzle of light and dark. The board is a square of lamps, some of them lit. Pressing a lamp switches it, and the lamps right above, below, left and right of it switch too: lit ones go dark, dark ones light up. Put every lamp out to solve the board.

Every board is made by pressing a dark board at random, so it can always be solved, and the game knows the fewest presses that do it. Boards come in three sizes, 5 by 5, 6 by 6 and 7 by 7, and a new board, the same for everyone, arrives every day.

How to play

Tap a lamp to switch it and its neighbours.

• Neighbours. A press switches the lamp you touch and the lamps directly above, below, left and right of it. Lamps on the edge have fewer neighbours, and corner lamps only two.
• Solved. The board is solved when every lamp is dark.
• Hints. A hint rings one lamp on the shortest way out of the board as it stands. Each hint adds 30 seconds to your time.
• Score. Your score is the time to solve the board, plus the hints. Every board size has its own leaderboard.

Strategy tips

1. Order does not matter. Pressing lamps in any order gives the same board, so you can plan a set of presses instead of a sequence.
2. Twice is never. Pressing the same lamp twice puts everything back as it was, so every lamp is pressed once or not at all.
3. Chase the lights down. Work from the top row down: under every lit lamp, press the lamp in the row below it. The rows go dark one by one, and only the last row can stay lit.
4. Read the last row. What stays lit at the bottom depends only on which lamps of the top row you press first. Try a few presses up top, chase down again and watch how the bottom row changes.
5. Spend a hint wisely. One hint early on the large board can save minutes of chasing.

FAQ

Is Lamps free to play?

Yes. Like every game on Play, it runs free in your browser, with no download and no account needed.

Does every board have a solution?

Yes. Every board is made by pressing a dark board at random, so the same presses put it back.

Does the number of presses count?

No, only the time does, with 30 seconds for every hint. Solving the medium board in the fewest presses possible, without a hint, earns a badge, though.

What is the daily board?

Every day everyone plays the same medium 6 by 6 board, so times compare directly on the leaderboard.

How is my score counted?

Your score is the time from the first look at the board to the moment the last lamp goes dark, plus 30 seconds for every hint. Lower is better.