Coin Stacks

There’s something noble about creating physical games. Games you can touch and feel and assemble out of random crap around your apartment. Half-Life 2 requires about a grand worth of computer equipment to play, this puzzle can be had at no more than $1.24* of your local coinage. And, best of all, you get to keep this coinage.

I’ve been thinking puzzle games, so here is one.

Take a piece of paper and draw a four by three grid on it. Make sure that the squares are big enough to hold a quarter. Now find four Pennies, four Nickels, and four Quarters and arrange them on the grid as such:

Puzzle Layout.

The rules for the puzzle are fairly simple. During a “turn” you can move a coin into an adjacent square on the grid (with or without a coin) so long as you meet the following requirements:

  1. You must alternate turns in the order of “Penny”, “Nickel”, “Quarter”. So, during your first turn, you can only move a penny. During your second turn, a nickel. Then a quarter. Then a penny again, and so on. If you can not make such a move, you lose. Start again.
  2. You can only move to a square adjacent to the coin (left, right, up, down) so long as that square is empty or occupied with coins of a different value (ie. no two coins of equal value can occupy the same square). Multiple coins in a square is called a stack.
  3. You can move a coin off of a stack as long as that coin has the lowest value in the stack. So you can move a penny off of a nickle or quarter and a nickel off of a quarter, but you can’t move a nickel off of a penny and, well, you can’t move a quarter off of a stack at all.
  4. Lastly, if you do get three coins on a stack, the stack is locked and you can no longer move coins off of it.

The main goal is to end up with four stacks and no loose coins. This isn’t too difficult to do. Once you do that, you can try the harder objectives:

  1. get four stacks, but position them so that they are laid out one per column (unless I screwed up, this one is doable).
  2. get four stacks of equal alignment (ie. all four would be “penny, quarter, nickle” or “dime, nickel, penny”). I don’t know if it’s possible to do this.
  3. get four stacks of equal alignment positioned one per column. (Once again, I don’t know if this is possible).

And there you go. A quick and easy puzzle. One that even frustrates me sometimes (I think that’s a good sign.) I call it Coin Stacks.

* if you are feeling frugal, you can replace quarters with dimes — but I like the size progression that comes with quarters. Even better, I suggest going with pennies, quarters, and loonies, but I guess this only applies to Canadians.

Modal image