• Perplexing Pyramid
• Giant Pyramid
• Warp-30
• Oskar's Disks
• Instant Insanity
• Archimedes' Square
• Tangoes

• 3 Tiny Tans
• Grand Tans
• Icosa-Triad
• Puzzling Pentagon
• Pocket Star
• Shape by Shape

This is the hardest of the size-4 pyramids around. Six crystal-clear pieces have a unique solution to form an order-4 tetrahedron on the terraced acrylic base. A second shape to build has only 3 solutions. We've also come up with some two-dimensional variations and "pseudo-solutions." Just ask us. Recommended for ages 11 to adult. $19

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The nine crystal-clear pieces of this monster fit just one way to make the order-5 tetrahedron on the contemporary-style terraced acrylic base. Solving it has been known to take anywhere from an hour to a year, or more. Solution is not included but is available. Recommended for determined teens to adults. $25

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Pack the 8 all-different crystal-like pieces (30 balls) into four different spaces: 2 sizes of box, 2 shapes of pyramid. These present four levels of difficulty. The easiest is the square pyramid, with hundreds of solutions. In fact, any one of the eight pieces can form the top, as we learned from our friend John Blasdale, who classified his 935 (to date) solutions by how certain pieces occupy the various levels. The rectangular pyramid is considered the most difficult—for the longest time it was believed to have just two solutions, until in September 2007 David Kausch sent us three he found by computer. Each has the same piece on top. David's computer program also identified 1061 solutions for the square pyramid. This figure is topped by Gordon Collins' 1120 solutions. Warp-30 is painstakingly handcrafted with a handsome 8"x8" wood base, clear acrylic box compartments and a brass-like plaque. A most appropriate executive gift. Test your co-workers' wits! For ages 12 to adult. $85

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Two nicely finished, 4" lasercut wood disks fit and move through each other's slots like a 3-D maze. It's not too difficult to solve but pleasant to do again and again. Best solution takes just 9 moves. We know of a prestidigitator who can solve it with just one hand. The linked position looks like a modern art sculpture. Cloth storage pouch is included. Oskar lives in the Netherlands and creates maze puzzles in his spare time. (Shipping discount) $25

This is the one! This classic cube puzzle has been a mind boggler since the early 1900s. It was popularized in the 1960s by Parker Brothers and has now been brought back by its original maker, Frank Armbruster. We have his new edition, in well-made plastic in a slotted tray that lets you view all four sides while you're solving. The object? Arrange the four cubes in the tray so that all four sides display four different colors. Infuriating. Each cube has all four colors, but in different arrangements, and it's extremely tricky to deduce which side should be up! If you're not familiar with this puzzle, here's your chance to experience what generations of puzzlers have struggled with. (Shipping discount) $8

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How cool is this? This solution can easily transform into any tetromino (the 5 shapes made of four squares), also known as Tetris pieces. If old Archie only knew!

This 14-tile dissection is the oldest documented puzzle in the world, and the decipherment of Archimedes' rediscovered manuscript is a hot topic among historical scholars and mathematicians. Also known as the Stomachion, it even made the front page of the New York Times, December 14, 2003. We are proud to offer a playable edition of this puzzle, perhaps the first publicly available in two millennia. Luminous transparent colors, in a sculpted 7" tray. Long unanswered:  Just how many ways can this square be solved? On October 31, 2003, Bill Cutler's program found the full answer of 536 distinct solutions. That means rotations, reflections, and switching of identical pieces are not counted as different. (Read the full story.) How many other convex shapes can the 14 tiles make? Bernd Rennhak in Germany found all 637 solutions. He also found that the set can solve 13 of the 14 tetratan shapes. The permutations are staggering. An amazing fact is that each tile's area is a whole number, based on the square as a 12x12 matrix. Here truly is ancient genius made visible. Some of the tiles' angles have sharp points, so we recommend ages careful 10 to adult.$35

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Tangrams are one of the oldest puzzles known, over a hundred years old, variously credited to the Chinese or the Greeks or an unknown designer. Rex Games' modern versions under the name Tangoes are superbly made, with two sets of nicely textured plastic pieces, a deck of 54 two-sided image cards, and a slim carry-case that doubles as display stand for two players to compete in solving. Ideal travel game, and you can buy supplemental decks to keep you challenged. For ages 8 to adult, 1 or 2 players. $9