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Imagine, a padlock without a key. That would be great, because you could open it without worrying about losing its key. But, there's a downside with this puzzle lock. To solve it, you'll need at least 250 steps - hence the name of the puzzle - which can take a while to open it. However, it's a perfect way to keep something of value locked, since it would discourage any thief from attempting to rob you, lest they would get caught with the hands in the cookie jar.

The Schloss 250 has a robust body made of laser-cut wood. Four pins are held in place in the middle and stuck between the four wooden plates that cross the lock from one side to the other. The pins can only be moved from left to right, but you have to unlock their path with the correct sequence. The movement of the puzzle could be better, because it can be stuck sometimes and you risk losing your concentration. Other than that, it's very well made.

The solution is simple, but at the same time, complex. This seems quite an incoherent thought, but it's actually true. The solving process implies the use of recursive mathematics, which means it has a specific set of rules that will repeat after a while. While it can be complex due to the number of moves needed to solve it, and also extreme concentration, once you understand the repetitive nature of the solution, it becomes very simple. This is a puzzle belonging to the group of 6-ary (remember that binary has only two states, 1 or 0), which means it has six different states. Understanding this notion will help you a lot in solving this challenging puzzle.

Closing Comments:

The Schloss 250 by Constantin is a true test to anyone's patience. With its whopping 250 steps, although it can take you more, only the most courageous will succeed in solving this fiendish puzzle.

Availability: PuzzleMaster is the place to get this great puzzle. If you want a less challenging puzzle or any other from Constantin, you can browse his available puzzles.