GerGame.
Puzzle · GerGame Original

Lights Out

★★★★☆ 4.4 / 5 · Editor-reviewed

Editor's review

Lights Out was released by Tiger Electronics in 1995. The math behind it is genuinely interesting — every solvable position has a unique minimum-move solution that can be computed via linear algebra over the field GF(2). We don't bother computing it, but we do guarantee solvability: every starting position is generated by applying random toggles to a solved board, so a solution always exists.

How to play

Click a cell to toggle it and its four neighbors (up, down, left, right). Goal: turn all cells off.

Controls

Click or tap any cell