# 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.

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### Name and solution of puzzle to rotate all arrows to same direction

In this puzzle, when you click an arrow, all arrows immediately next to it (diagonally included), as well as the arrow you clicked itself rotate 90 degrees. The goal is to get all the of arrows to ...
905 views

### Flip counters in a grid so that they alternate in color

Beginner puzzle This puzzle is intended to be suitable for people who are new to puzzle solving. Clarification: Both experienced solvers and new solvers are welcome to post solutions to this puzzle. ...
967 views

### Minimum number of flips needed to fully set a binary string

Source: My school teacher, it was just given as a problem statement. Problem: You are given a binary sequence $S$ of up to $10^6$ bits. You wish to set all the bits in the string to $1$, but the catch ...
89 views

### An array of light-bulbs [duplicate]

There is a grid of 2024 by 2024 light-bulbs. Initially, all bulbs are off. You can switch the state of all 2024 bulbs in a row simultaneously, or all 2024 bulbs in a column simultaneously, and do this ...
1k views

### How do I determine whether a 5x5 Lights-Out puzzle is solvable without trying to solve it?

The following two 5x5 Lights-Out puzzles are not solvable. Is there a way to find out why, without trying to solve them? [1, 0, 0, 1, 0] [1, 1, 1, 1, 0] [1, 1, 1, 0, 0] [0, 0, 1, 0, 0] [1, ...
2k views

### Prime lights out

You start with a 4x4 grid filled with zeroes. If you press a cell then the cell and all its neighboring (horizontally and vertically) cells will have their numbers increased by 1. What is the most ...
483 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 ...
399 views

### Different numbers in all cells of a 4x4 board

This is a harder version of this puzzle: Different numbers in all cells of a 3x3 board Zeroes are written in all cells of a 4×4 board. Pressing a cell increases by 1 the number in this cell and all ...
2k views

### Deemo II Candle Puzzle

I have come across an interesting candle puzzle when playing Deemo II. The puzzle has 8 candles with 2 states: on(○) and off(●). Initial State All candles are off: ● ● ● ● ● ● ● ● Allowed Operation ...
1 vote
1k views

### What's that puzzle where multiple levers change the locks' states on one door?

I have seen this one a few times in videogames and elsewhere, but I don't remember where. You have to open one door that has several locks on it. You have a bunch of levers that when moved change the ...
464 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 ...
235 views

### Maximising the number of lit lightbulbs through row-column toggling

You have an $n\times n$ grid, with each cell containing a lightbulb. On a move, you may select a lightbulb, and toggle the state of that lightbulb, and all other lightbulbs sharing a row or column. ...
306 views

### The combinational switching lights

You have probably encountered the mini puzzle in various games where you have a set of switches and a set of lights (or other triggers), such that each switch "flips" the states of one or ...
181 views

### Highest n where an equal number in all cells is (im)possible

Inspired by Board with all 2020s : Zeroes are written in all cells of a n×n 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. ...
1k views

### Flipping coins in a circle

We have a set of N coins that are all placed in a circle. They all have "Tails" as their face up side. The coins are all distinct and have numbers (1,2,3...N) written on them. In each move, ...
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 ...
871 views

### Will you be the first to get free?

It is your first day in prison and you are approached by a guard having a hunch for puzzles. He tells you that he gives every new prisoner the chance to be freed if they can present him with a version ...
4k views

### Is there any easy way to solve this lock puzzle?

https://js13kgames.com/games/lock-puzzle/index.html The link provides an online puzzle game of $16$ tiles in the form of a $4 \times 4$ matrix of which some entries are in the form of vertical tiles ...
284 views

### A generalization of the lights-out problem

Look here for the original problem. Let the set $J$ be the set of pairs of positive integers $(m,n)$ with $m\ge n$. Suppose $(m,n)\in J$. Then there are $m$ lights, which they are initially off. ...
449 views

### What's the name of this kind of puzzle? [closed]

Link to a video of a the puzzle What is this puzzle called, and if possible, what is the logic behind it? Clicking a square inverts the state of the square and the ones directly adjacent to it, and ...
174 views

### Fill 5 x 5 grid

In each cell of a 5 × 5 square there is a token that is black on one side and white on the other. Initially all tokens are placed with the white side facing up. On each move three tokens in ...
3k views

### I am struggling with a complex version of the "lights out" puzzle

Hello my fellow puzzlers. I am new to this holy land so if my question is not the kind you people like to solve, I apologize. As some of you may know, there is a puzzle named: "lights out" based on a ...
556 views

### Lights out game on a chessboard

Alice and Bob play a game with an 8×8 grid of lights, all initially on. They take turns choosing a light which is on and turning it off, with Alice going first. However, the grid is rigged such that ...
1 vote
581 views

### Which Lightbulb belongs to the switch [duplicate]

There is an old house with an upstairs room and a downstairs room. the upstairs room contains 3 light bulbs and the downstairs room contains 3 switches. Each switch is connected to one light bulb. A ...
2k views

### Strategy for Modified Lights out

A friend of mine showed me a variation of lights out that they were interested in, and asked me if it would be possible to solve any given empty grid. This variation involves toggling not just the ...
385 views

### Is a game of Knight's out possible?

In lights out, there is a grid of cells (called lights) that can assume two states. All lights start off. You can toggle a given light, and it will automatically toggle its four neighbours. The aim of ...
6k views

### Grid based color changing puzzle

I am trying to identify the minigame used in the game Fontanero (the code for it is here). It consists of a 3x3 grid of squares, and each square is red or green. You can click on a square to invert ...
961 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. ...
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 ...
355 views

### Putting up the lights two

I hope you are familiar with this. Basically Each strand of 20 lights is wired like a 5x4 grid, and each bulb can be either blue, red, purple, or green. However, when you change the color of 1 ...