Lights Out

Lights Out is a compact logic puzzle on a 5×5 grid of lamps. Pressing any tile toggles it together with the tiles directly above, below, left and right of it. The aim is simple to state and tricky to reach: turn every light off.

Each board is created by pressing tiles at random from a dark grid, so a solution always exists. A handy fact to remember is that the order of your presses never matters and pressing the same tile twice cancels out — so the whole puzzle is really about choosing which tiles to press once.

Turn all the lights off. Your move count is shown at the top; solving the board in fewer presses is the real challenge.