Lights Out

At the start of play a pattern of lit buttons is chosen by the machine. By pressing the buttons the player can alter the state of some subset of the buttons according to the rule we will describe below. The aim of the game is to turn all of the lights out (get it? :-)) The effect of pressing a button is to toggle the state of that button, and of its immediate vertical and horizontal neighbours.

The game has 3 modes. In mode 1 you are presented with 50 increasingly difficult puzzles. You have to solve one puzzle before you can move on to the next. The aim of the game is to solve them in the minimum possible number of moves, however you are allowed to go over this minimum by 10. Mode 2 gives you another 1000 puzzles to solve. Mode 3 allows you to enter your own puzzles, however not all the possible configurations of lights are solvable (in fact exactly one quarter of them are) so you need to be a bit careful here!

If you don't own an original Lights Out then you should! However there are plenty of other ways to play the game. For a start you can play my own Javascript Lights Out game, which is (IMHO) pretty good. There are plenty of other versions available on the Web, take a look at my links page - you can even download a version for a TI-86 calculator!

Solving Lights Out

If you want to know how to solve Lights Out puzzles, you can visit my Solving Lights Out pages. There you will find a description of a method called "Light Chasing". It's very simple, but doesn't always give you the shortest solution!

Of course if you're stuck on a particular puzzle, you could always cheat (!) either by entering the puzzle in on my Javascript Lights Out game, which will always give you the shortest solution, or - if it's one of the 50 puzzles from Mode 1 of Lights Out, the solutions are available from the Lights Out Fan Club pages.

More Information

If you are looking for more information about the actual physical Lights Out game, then you could download the manual as a PDF file from the Lights Out Fan Club pages. These pages are definitely worth a visit.

If you'd like to know how my Lights Out program (and several others) can always work out the shortest solution, there will be some pages up on this site soon. You'll need to know a bit of Linear Algebra, but it's not too hard. In the meantime, why not track down some of the papers listed in the Links section.

And finally, if you are as much of a sucker for detailed information as I am, why not check out the Lights Out Patent on the IBM Patent server (I'll put the link in here soon). It's patent number 5,417,425