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Lights Out
Turn off all sixteen lights. Each press changes the selected light and its horizontal or vertical neighbours.
Spatial logic · no account needed
How to play
Click a square to change that light and each immediately adjacent light (up, down, left and right). Lit lights turn off; dark lights turn on. The aim is to make the entire grid dark.
Every new board is made by applying legal moves to an all-off board, so at least one solution exists. The hint identifies a move in a valid solution from the current position.
Lights Out strategy
Random clicking quickly becomes confusing. Instead, work systematically and watch the pattern each press creates. Because pressing the same square twice cancels its effect, you never need to press one square more than once in the same plan.
- Try to clear one row while keeping track of what the next row must correct.
- Use the hint when you want to study one move from a valid route rather than restart.
- If a sequence makes the board worse, repeat those same presses to undo it.
Why this is a logic puzzle
Each move has a predictable local effect, but several moves interact across the grid. The challenge is to reason about those combined effects rather than judging one press in isolation. That makes Lights Out a compact exercise in state changes and systematic search.
Try Pattern Detective for number logic or logic brain teasers with answers.