Light Toggle
Click a light to toggle it and its neighbors. Turn all lights off to win!
FAQ
Lights Out is a logic puzzle where pressing a light toggles it and its neighbors on or off. The goal is to turn off all the lights. It was originally an electronic toy released by Tiger Electronics in 1995.
Not every configuration is solvable. On a 5x5 grid, exactly 4 out of every 32 possible configurations have no solution. The puzzles in this game are guaranteed to be solvable.
The most systematic approach is the top-down method: solve the top row by pressing buttons in the second row, then the third row, and so on. If the bottom row is not solved, try different first-row combinations.
About this test
Light Toggle is based on the classic Lights Out puzzle. Press lights to toggle them and their neighbors — turn them all off to win.
How It Works
Each cell is a light that can be on or off. Pressing a light toggles it and all orthogonally adjacent lights. Turn off all lights to complete the puzzle.
Mathematical Beauty
Lights Out can be solved using linear algebra over GF(2) (the field with two elements). Each button press is a vector, and the solution is a system of linear equations. This makes it both a fun puzzle and a gateway to abstract algebra.
Tips
- Work from top to bottom — solve each row by pressing buttons in the row below
- The order of presses does not matter, only which buttons are pressed
- Pressing the same button twice cancels out — each button needs at most one press