Lights
Dusk in a walled garden. Place lanterns until every open square glows. Lanterns shine along their row and column up to the nearest wall, and must never shine on each other.
How to play Lights
How to play
Tap a square to place a lantern, tap again for a dot (your note that no lantern goes there), and once more to clear it. Drag across empty squares to dot several at once.
The rules
Every open square must be lit. A lantern lights its own square and shines up, down, left and right until a wall stops it. Two lanterns may never shine on each other. A number on a wall says exactly how many lanterns touch its four sides.
Tips
Start with 0s and 4s, then 3s against an edge. Look for dark squares that only one spot can still light. A number turns pale when it is satisfied and pink if it has too many lanterns.
Keyboard
Arrow keys move between squares. Enter or Space cycles lantern, dot and empty. Press X or the full stop for a dot, Backspace to clear.
Questions
Does every Lights puzzle have exactly one solution?
Yes. Each puzzle is checked by an exhaustive search for exactly one answer, and by a step-by-step solver that reaches it by reasoning alone, without guessing.
What do the levels mean?
Easy puzzles use only the basic rules: full numbers, numbers that need every side, and squares only one spot can light. Medium puzzles also need you to spot lanterns that would leave a square dark. Hard puzzles add short what-if chains.
What does the hint do?
It works out the next step from your current position, places it, highlights it and tells you why. If one of your lanterns or dots is wrong, it fixes that first.
Is this the same as Light Up or Akari?
Lights uses the same classic rules as the lantern puzzle known under those names. Our puzzles are original and free to play.