This week, I wanted to share a use I found for our Dwarven Tower Coins, licensed from 13th Age. In the Dragon Empire, these coins are the dwarf-made standard gold currency found in markets and inns the world over. But using only a Dwarven Ziggurat set (one of each denomination), I brought a classic puzzle to the table in a very satisfying, tactile form.
The Tower of Hanoi is a mathematical logic puzzle, using a number of disks of different sizes (or in this case, 3 Dwarven Tower coins). In my 13th Age campaign the adventurers encountered a locked door in a dungeon with a pile of coins set on an alcove nearby. A mysterious magical magnetic field enforced the following restrictions:
- The coins could only be placed in one of three slots in the alcove.
- Only one coin could be picked up at a time.
- Only the top coin of a pile could be moved.
- It was impossible to place a larger coin on top of a smaller coin.
An engraving in the wall indicated that to open the door, the coins should all be moved from the leftmost slot to the rightmost, and that it should be done in exactly 7 moves (the minimum amount possible).
I found the Dwarven Tower coins to have the perfect form factor for this puzzle. But it could be done using any coins of increasing size, such as those found in our regular gold range. Increasing the number of coins will significantly increase the difficulty.
A word of warning: if, like me, your players are engineers, programmers, or mathematicians (or students thereof), they probably already know the answer, and this puzzle will not stump them for long. You can see the exact solution on the Tower of Hanoi Wikipedia entry . But I found to be a nifty way to engage their spatial reasoning in the real world, while they get their hands on satisfyingly tactile and well-made props!