About

Panex is a puzzle that was invented by Toshio Akanuma. It resembles the tower of Hanoi, but it is in fact a lot more difficult. It has two towers of 10 pieces. Instead of being made from disks threaded on pegs, the towers are made of pieces that slide along a track. There are 3 vertical sections of track, similar to Hanoi's three pegs, where a tower can be built. These 'pegs' are exactly long enough to hold a completed tower plus one extra piece. A horizontal track connects the top of the three pegs, so that pieces can move from the very top of one 'peg' to the next. At the start, the left peg contains a blue tower, the right peg an orange tower, and the middle peg is empty. The aim is to swap the two towers. The problem is however that disks cannot freely slide all the way down each peg. A disk cannot move to a position lower than where it belongs in a finished tower. There are two versions of the Panex puzzle. Panex Silver has blue and orange towers as explained above. From the size of blue/orange shape on each piece you can immediately see at which level it belongs in the finished tower. The Panex Gold however has pieces that look identical, one tower grey and the other brown, making it more confusing still. This is one of the most difficult puzzles on my site. Partly this is because it is hard to do, but also because the solution is extremely long. It is thought that the optimal solution of Panex needs more than 31000 moves. The Japanese collector whom I bought it from did solve it (the Silver version), but it took him 2 months, an hour a day. If your browser supports JavaScript, then you can play the Panex by clicking the link below. Its built-in solver is not optimal, but is pretty good considering that it can solve any random position.