Wednesday, 11 July 2018


Eric Fuller’s latest batch of puzzling goodness contained a really eye-catching little number called X-Cage. This one comes from the fertile imagination of Frederic Boucher, the designer who brought us some other recent Fuller-creations like Artefacts and Marble Cake Plus – Boucher-san knows his packing puzzles!

This one gives you a set of 5 Yellowheart cross-shaped pieces and a Walnut frame with a captured acrylic plate serving as a lid. There’s a handy square hole cut in the acrylic, big enough to allow a single piece to be inserted into the frame… clearly the intention is to place all five Yellowheart pieces into the frame.

Start with the obvious closely packed array and you soon realise that the pieces are slightly too big for the cage – so either Eric’s got the cage’s dimensions wrong (Aye, right! – gorgeous Glasgow phrase where two positives make a negative!) or you need to try harder…

OK, engage puzzling brain – obviously the standard orthogonal packing isn’t the best use of space here, so let’s try a few of Stewart Coffin’s favourite tricks and try some different angles… some might seem promising, but ultimately, none of them seems quite good enough…

Sit back, smile, tip of the hat to Boucher-san, and then Think(c).

Think and experiment. Quite a lot. And then apply the old Holmesian logic of whatever remains after eliminating the alternatives must be the solution, no matter how strange it might appear… and if I’m honest, I went through a good few of those before I eventually struck puzzling gold – and a fat grin spreads across my ugly mug and I mutter something under my breath about the designer – he’s good, really good.

This is a great puzzler’s puzzle – definitely one to taunt other puzzlers with. 

Guaranteed to plant a huge sense of satisfaction on anyone solving it… oh, and Eric’s done his usual rather superb job, in spite of my initial doubts! ;-)


  1. I'm glad you enjoyed the X Cage dear Allard-san : )
    Many thanks for the nice review!
    I am grateful to Eric for his great work.
    -Frederic Boucher

    1. pleasure - both in solving and in writing, Frederic! :-)