CISRA Puzzle Competition 2012 - Solutions

4B. Caverns

This puzzle presents what look like maze pieces, somewhat similar to puzzle 1D Labyrinth, only more of them, more complicated, and without any indication as to how they are meant to be assembled.

The secret to assembling the pieces is to overlay them in pairs. When the right pairs are overlaid the patterns of maze walls align exactly over part of the pieces, while in the remainder of the area the walls form a complete grid in which every possible wall position is filled. When all the pieces are so matched into overlaid pairs the resulting patterns can be assembled in jigsaw fashion to form the following:

The letter-number pairs are grid coordinates indicating the two overlaid pieces, indexed as shown below on the original two pages of the puzzle:

In the assembled jigsaw the areas of fully complete grid are shown shaded and form letter shapes that spell out "TSOJCANTH".

The Lost Caverns of Tsojcanth is a classic Dungeons & Dragons adventure module. The name ties in with this puzzle's title (Caverns) and also the solution of puzzle 1D Labyrinth (LOST). The solution to this puzzle is TSOJCANTH.

Puzzle design notes:

This puzzle was originally designed without the small north-point markers on each piece.

When given to two test solvers, they racked their brains on the puzzle fruitlessly for three days, trying things like building a large maze to solve, connectivity analyses, attempting to extract Morse code from the wall shapes, and so on.

I (the puzzle creator) suggested a third member of our test solving team give the puzzle a go. I knew this third solver did not have the mindset and patience required for a deep topological or cryptographical analysis of the puzzle. He indeed looked at the puzzle and complained that it looked "too hard" and it seemed to be exactly the sort of puzzle that he would hate trying to solve. Nevertheless, he looked at it. Within five minutes he said, "I really don't want to do anything with this. It looks way too complicated. All I want to do is try putting pieces on top of one another and holding them up to the light to see if I can see any patterns."

Within the next twenty minutes, he'd solved the puzzle completely.

This assured us that the puzzle was in fact solvable. The testers suggested adding the north-point markers to indicate that the individual pieces were not meant to be rotated, as, no matter what approach you take to try to solve the puzzle, adding rotations blows out the search space by a huge amount.