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Lights Out






About Lights Out

This applet is based on a game that has several variations. The version presented here is common, though more complicated editions exist (such as lights with more than two states). Given a random starting configuration, the goal is to find a sequence of "moves" that will turn all lights out (so all blocks are black). Pressing one light will change its state, as well as the state of its four nearest neighbors.

This applet provides several choices for starting configurations - be warned that not all of them have solutions!

A special thank you goes out to all Math 150 students in Spring 2016 for their puzzle contributions!

Using the Applet

Tap a square to flip its "switch" along with its nearest neighbors. The puzzle is complete when all squares are black.

About the Applet

This applet was created using JavaScript and HTML Canvas. No other libraries/dependencies are required. If you are having trouble viewing the applet, be sure JavaScript is enabled in your browser. Click here for instructions. Internet Explorer is not recommended for this applet. This applet was last updated June 2018.