bopHow to Solve Lights Out: Row Chasing on a 5×5 Board
Clear a Lights Out board row by row, follow a checked three-move example, and learn what to do when the last row stays lit.
To clear a light in one row, press the square directly below it. Work downward, then check the bottom row. If lights remain, restore your starting board and try a different first-row pattern.
Lights Out looks like a puzzle about individual squares, but every move changes a small cross. Pressing a square switches that square and its neighbors above, below, left and right. Edge moves affect fewer squares because some neighbors do not exist.
The useful trick is to finish one row at a time. This guide applies to Bopbun’s five-by-five board and includes a small example you can check without guessing.
Two rules that make planning easier
Pressing the same square twice cancels its effect. Also, the order of a set of presses does not change the final pattern: each light only cares whether it was switched an odd or even number of times. Keep a note of the squares you press instead of trying to remember a long sequence.
Bopbun creates each new board by making legal moves from an all-dark board, so its starting puzzles have solutions. A solution you find this way is not necessarily the solution with the fewest presses.
Chase the lights downward
A press in row 3 cannot reach row 1, so it does not undo the row you already finished. That is why moving downward is more predictable than jumping around the board.
- Start with the top row. For every lit square in row 1, press the square directly beneath it in row 2.
- Once row 1 is dark, inspect row 2. Clear its lit squares by pressing the matching columns in row 3.
- Repeat for row 3 using row 4, then for row 4 using row 5.
- Check the last row. If every square is dark, the board is solved.
A checked three-move example
This example is a practice pattern, not a fixed level code. Count rows from the top and columns from the left. In the diagram, a filled circle is a light that is on.
Press row 2, column 2; then row 3, column 2; then row 5, column 4. The first press clears the top row, the second clears the next unfinished row, and the third removes the remaining cross.
Starting board
| ○ | ● | ○ | ○ | ○ |
| ● | ○ | ● | ○ | ○ |
| ● | ○ | ● | ○ | ○ |
| ○ | ● | ○ | ● | ○ |
| ○ | ○ | ● | ● | ● |
After row 2, column 2
| ○ | ○ | ○ | ○ | ○ |
| ○ | ● | ○ | ○ | ○ |
| ● | ● | ● | ○ | ○ |
| ○ | ● | ○ | ● | ○ |
| ○ | ○ | ● | ● | ● |
After row 3, column 2
| ○ | ○ | ○ | ○ | ○ |
| ○ | ○ | ○ | ○ | ○ |
| ○ | ○ | ○ | ○ | ○ |
| ○ | ○ | ○ | ● | ○ |
| ○ | ○ | ● | ● | ● |
After row 5, column 4
| ○ | ○ | ○ | ○ | ○ |
| ○ | ○ | ○ | ○ | ○ |
| ○ | ○ | ○ | ○ | ○ |
| ○ | ○ | ○ | ○ | ○ |
| ○ | ○ | ○ | ○ | ○ |
What if the last row will not clear?
The first downward pass can leave lights in the bottom row. Pressing those last-row lights directly also changes row 4, so it usually sends you back into repairs.
Instead, return to the same starting board by pressing every square from your recorded trial once again. Then choose a different combination of presses in the first row and chase downward again. Five first-row squares give 32 possible on/off press combinations, including pressing none. For a solvable five-by-five board, trying these combinations and chasing each one will include a solution.
Choose New round only when you want a different puzzle. It does not restore the board you were trying to solve.
A simple habit for your next round
Before pressing anything, inspect the first row and decide how you will record moves. Clear one row, pause, and check the next. If a finished upper row lights up again, you probably pressed too high or miscounted a column. Slowing down for that check is often more useful than making another speculative move.