The Bishop Cubes were yet another entry of last year's 31st IPP. Invented by Forrest Bishop, in 1992, this shape-shifting puzzle was finally  made commercial available in late 2010.

A set of Bishop Cubes contains 27 colored smaller cubes in a 3x3x3 cube. Each cube has three colors (yellow, red and blue), and two types of tracks - one for every opposite face. This track design is what makes the cubes slide within the limits of the cube and allow countless shapes to be formed.

There are various challenges that you can try. The most obvious is to change the cube to a random shape and then return it to its original form. You can also change from one shape to another, but keeping in mind not to disconnect any cube from the set. By taking advantage of the cube's colors, you can try to make different colored patterns. Finally, a simple, but also challenging task is to move one particular cube from one part of the cube to another, with the same rule of not disconnect any cubes.

To move a certain number of cubes, there are three possibilities. They will slide accordingly in one of three axis at a time (xyz). A nice feature to let you know that they were moved correctly is by a form of a "click", otherwise they would just slide off the edge.

To get more acquainted with the puzzle's mechanics, you can take eight individual cubes and build a smaller 2x2x2 cube. This way, it gets much simpler to learn how the cubes interact with each other, before attempting other more complex challenges. There are also three basic moves you should know: the slab move, which makes a sheet of cubes slide back and forth; the row move, as the name suggests, only moves one row in a certain direction; and finally the single-cube move will of course let you slide a cube at a time when one and only one face is connected to the set.

The first challenge that I tried was to scramble the cube and solve it to its form again. This proved to be much harder than I was expecting. After only a few random movements, the puzzle form was beyond recognition and when I tried to reverse the movements, it did more damage than good. I remember that it took more than one hour to finally get it to a cube shape again.

Making other shapes is very fun as well. There are endless possibilities, but you can expand the cubes capacity as well, by connecting two or more sets to make even more complex shapes. I have tried a few, some of them found already in the booklet, and others by trying slightly different variations. In a few of them, I admit to have cheated, as I'm a bit lazy to return them to the cube form in order to try a new shape, so I end up taking all the cubes apart and assemble the cube freestyle...

To buy your set of Bishop Cubes, just stop by their official website.

The Bishop Cubes is an original puzzle that takes the shape-shifting category to a whole new level. It's extremely fun to solve, just by returning it to a cube form and the extra challenges are a nice way to keep it fresh, avoiding this way to get bored more quickly. 

As many other shape-shifting puzzles, there's no particular goal. Your creativity is your ultimate building tool. How many different shapes can you build?