Equal7

(Click to Enlarge)

Gravity Puzzles are not a recent invention. In fact, one of the first puzzles in this category, the Bloxbox, appeared in 1972 and was invented by Piet Hein, the inventor of the Soma Cube. Equal7 was designed by Vladimir Krasnoukhov in 2012 - notice that I'm not saying "invented" because this concept already existed - and it gives a new twist to the sliding blocks/gravity puzzles by adding a much more difficult challenge.

Equal7 is to a regular gravity puzzle what a Rubik's Cube 5x5x5 is to a Rubik's Cube 3x3x3. That's a simple analogy to make you see how difficult and more demanding the Equal7 puzzle really is. There are many different challenges, but fear not, as there are easy levels, as well as medium and hard ones. Are you good at addition?

The Equal7 puzzle is a cube measuring about 5cm in diameter. Inside it are seven special dice, with each face marked with one to five dots - the face where six dots should've been is just blank. The empty space allows for the dice to slide and move across the cube by tilting it, creating a dynamic environment where each face of the cube is always changing with each move you make.

The idea is to get the same number of dots on all six faces of the cube at the same time. As mentioned above there are different challenges, each one asking you to get all faces of the cube with a different number of dots. The easiest difficult level is to get all six faces of the cube with exactly 10 dots. Level 2 requires you to have all faces with 11 dots. Level 3 with 12 dots. And finally, the hardest level is for you to get exactly 7 dots on each face of the cube. Doesn't seem logic, having the hardest level with the fewer number of dots, but believe me, it's very difficult.

(Click to Enlarge) - Notice the painted die in the front

The cube has a special feature which allows the proposed challenges to be a little "different" - not sure if I should classify them as easier or harder. Since each of the cubes' faces can be divided in four, which carry four dice, there are three faces of the cube where the space of a die is already painted with a specified number of dots. Any die can be placed behind this space, but it will not be visible. Since the total of dots in that space is already pre-determined, you can anticipate which dice should be used for the other three spaces.

Adding this constraint can be viewed as making the puzzle both easier or harder, depending on your interpretation of the puzzle's concept. On one hand, you don't need to worry about that space, since any die can be placed behind it, but on the other hand, it restricts the number of possibilities, thus making it harder getting the right die for the other three spaces. Whichever your interpretation, though, one thing is certain... Equal7 is a great puzzle, capable of challenging even the sharpest minds.

Closing Comments:

Equal7 by Recent Toys isn't a puzzle for mathematicians only, and even though it seems intimidating, it can be extremely fun to play with. The movement of the dice sliding inside the cube is very smooth and satisfying. The different levels of difficulty allows for everyone to try it, even a beginner.

Availability: The Equal7 is available to purchase at PuzzlesdeIngenio.com for €11.50.