Lights Out

How to play

The 5 by 5 grid starts with a scatter of lit tiles, and your job is to switch every one of them off. Tapping a tile toggles it along with its four direct neighbors, which is what makes this tricky: fixing one corner can relight another. Clear the board to advance, and each level starts from a more scrambled pattern.

Tips

• Order never matters, and tapping the same tile twice cancels itself out. All that counts is which set of tiles you tap.
• Try light chasing: sweep top to bottom, tapping the tile directly below each lit one to push all the light into the bottom row.
• Tapping tiles that are already dark is often part of the solution, so do not treat lit tiles as the only legal moves.
• Every board is scrambled from a solved grid with at most 15 taps, so a solution always exists and it is never a long one.