How to Solve Lights Out Puzzles: The Strategy Behind Nightlit

Lights Out looks like a puzzle you solve by luck: you tap a tile, five tiles flip, and the board gets worse. It isn’t luck. Lights Out has a simple, reliable method that solves any solvable 5x5 board, and once you know it, you can focus on the fun part: solving in fewer moves. This guide walks through that method using Nightlit, a daily take on the puzzle where the goal is to light every tile gold.

The rules in one line

Tapping a tile flips it and its four direct neighbors (up, down, left, right). Tiles on the edge have fewer neighbors, and corners have only two. In Nightlit, a solved board is all gold.

Two facts that make it solvable

1. Order doesn’t matter. Tapping A then B gives exactly the same board as tapping B then A. So a solution is really a set of tiles to tap, not a sequence.

2. Tapping twice does nothing. Tap a tile twice and every flip cancels out. So in any efficient solution, each tile is tapped once or not at all.

Step 1: Chase the lights down

This is the core technique, usually called “chasing the lights.”

1. Look at the top row. Leave it as it is for now.
2. For every tile in the top row that is still dark, tap the tile directly below it in the second row. That tap flips the dark tile above it to gold without touching anything else in the top row.
3. Now the top row is fully gold. Move down: for every dark tile in the second row, tap the tile directly below it in the third row.
4. Repeat for the third and fourth rows.

When you’re done, the top four rows are all gold. Any dark tiles left are stuck in the bottom row, and there’s no row below them to fix them from. That’s normal.

Step 2: Read the bottom row and fix the top

Here’s the clever part. On a 5x5 board, there are only seven possible bottom-row patterns you can end up with, and each one has a known fix: tap certain tiles in the top row, then chase the lights down again.

Positions are numbered 1 to 5 from left to right. X is a dark tile, . is gold.

After those top-row taps, the top of the board will look messy again. That’s expected. Chase the lights down one more time, row by row exactly as before, and the bottom row will come out clean. The whole board is gold.

You don’t need to memorize the table. Remember two or three common rows and look up the rest until they stick.

Why the method works

Every tap in step 1 is forced, so the top row decides the whole solution. The table is just a list of top-row choices that cancel each leftover bottom pattern. A bottom pattern missing from the table means the board wasn’t solvable, which won’t happen in Nightlit: every board is generated by scrambling a solved grid with taps, so a solution always exists.

Step 3: Get closer to par

The chase method is guaranteed, but it isn’t always short. Nightlit gives each daily board a par, the move count of a shortest solution. Meet par for three stars; finish within a few moves of it for two.

A few habits help you get closer:

• Cancel doubles. If the chase has you tapping a tile you already tapped, those two taps cancel. Skip both.
• Look for “plus” shapes. A cluster of five dark tiles in a plus shape is solved by one tap in its center. Spot those first.
• Learn the board’s corners. A corner tap only flips three tiles, so it’s a precise tool for fixing small edge problems without disturbing the middle.

What about 6x6 and 7x7?

Nightlit’s hard modes use bigger boards. Chasing the lights works exactly the same way. The difference is the lookup table: on 6x6 and 7x7, every board has exactly one solution and the tables are much longer, so you’ll work out the top-row fix by experiment instead of memory. A good next challenge once 5x5 feels easy.

Try it on today’s board

The best way to learn the method is to use it once. Open today’s Nightlit puzzle, chase the lights down, check the bottom row against the table, and see how close you get to par. Then try tomorrow’s without peeking.