# Questions tagged [lights-out]

A type of puzzle typically involving a grid of lights, in which the challenge is to get them all to the same state (on or off). The trick is that each light also affects a number of its neighbors, with sides and corners affecting fewer.

7 questions
Filter by
Sorted by
Tagged with
1k views

### Board with all 2020s

Zeroes are written in all cells of a $5 \times 5$ board. We can take an arbitrary cell and increase by 1 the number in this cell and all cells having a common side with it. Is it possible to obtain ...
• 880
863 views

### Turn on all squares

Take a square grid of size $a\times b$, with all squares being off. You can tap a square, to reverse the state of that square and all squares located in the same column and row as the tapped square. ...
• 2,868
308 views

### Putting up the lights

Feeling festive, you decide it's time to put up the lights. You dig out the box and plug a strand in. Uh oh, they are all the same color. This won't work, these are supposed to be multiple colors ...
• 6,639
1k views

### Counter Flipping

A counter flip game is played in the following way: In each move, you can flip an entire row or column Flipping a row or column inverts all the counters on that row or column from $X$ to $O$ or vice ...
• 170
476 views

### Different numbers in all cells of a 3x3 board

This puzzle is inspired by this one: Board with all 2020s Zeroes are written in all cells of a 3×3 board. Pressing a cell increases by 1 the number in this cell and all cells having a common side with ...
• 33.1k
446 views

### How to get the least number of flips to a plastic chips to get a certain figure?

The puzzle is as follows: (Transcription with grammar errors fixed) A game consists of the following: The challenge is to flip the chips in such a way so that they are as in state 2. You start in ...
• 1,545