Something or other, whatever!

Christian Lawson-Perfect's homepage


Double Back

A puzzle where you have to reverse the order of two lines of numbered baubles. Invented by Ed Kirkby.

Circular lights out

A circular version of the Lights Out puzzle. The aim of the game is to turn all of the lights off. When there is an evenly-spaced sequence of bulbs all turned off or all turned on, you may switch them all on or off by clicking two consecutive lights in the sequence.

Lights modular out

A move in the classic Lights Out puzzle could be viewed as addition mod 2. This lets you set up a version of the puzzle where it's addition modulo something else.

Pancake flipping

An interactive toy for the pancake-flipping problem, to go with a post by Katie Steckles on The Aperiodical. By repeatedly flipping the top part of a stack of pancakes, can you sort them by size?