Lights Out
Turn every light off. Each tap switches a light and the lights directly above, below, left and right of it.
Moves 0💡 0
Tap a square to switch it and its four neighbors.
How to play
Some lights on the 5 × 5 board are on. When you tap a square, it switches, and so do the four squares touching its sides. Lit squares go dark, and dark squares light up. Your goal is to turn every light off.
The chase-the-lights method
- Look at the top row. For every light that is on, tap the square directly below it in the second row. The top row goes dark.
- Do the same for the second row, tapping the third row, and so on down the board.
- Now only the bottom row may have lights left. Remember which ones, tap a few squares in the top row and chase the lights down again. With a little practice you will learn which top-row taps fix each bottom-row pattern.
Good to know
- The order of your taps does not matter. Only which squares you tap does.
- Tapping the same square twice does nothing, so never tap a square more than once in a solution.
- Every puzzle here is created by random taps from a dark board, so it can always be solved.
A puzzle with a glow
Lights Out was first sold as a handheld electronic toy in the 1990s, and mathematicians love it because it can be solved with simple algebra. You do not need any math to enjoy it, just patience and a plan.