💡 Light Flip
🧩 Logic · 1 playsLight Flip
Switch off every light, knowing each press also flips its neighbours.
About Light Flip
A grid of lights in which pressing any one switches that light and the four directly adjacent to it. The board starts fully lit and must be turned entirely off. Because a single press affects five cells, the board cannot be cleared one cell at a time; the reliable method is to work down the grid row by row, using each row to correct the one above it, then resolve whatever remains along the bottom edge. Note also that pressing a light twice undoes itself, so only the set of lights pressed matters, never the order. A par score is set for each level.
How to Play
Press a light to toggle it along with its neighbours above, below, left and right. Turn every light off to complete the level. Pressing the same light twice restores the earlier state, so the order of presses does not matter.
💡 Tips & Strategy
The essential insight is that pressing a light twice undoes itself, so only the set of lights you press matters — never the order, and never pressing anything more than once. That reduces a seemingly chaotic puzzle to choosing a subset, and it means you can plan the whole solution before touching anything.
Solve it row by row with a technique called light chasing. Work across the top row in whatever way looks reasonable, then, for every lit cell in the top row, press the cell directly beneath it. That clears the top row permanently. Repeat downward and all rows but the last come out clean.
Whatever pattern remains in the bottom row is decided entirely by your opening row. A small number of bottom-row patterns correspond to each valid first row, so if the last row does not clear, restart and vary only the top row — you are searching a handful of options rather than the whole board.
Beating par means finding the smallest such subset. Since pressing a cell toggles itself and its four neighbours, cells in the corners and along the edges affect fewer lights, which makes them cheaper to include and often the key to a tidy solution.