How to Solve Haunted Castle Puzzles
Haunted Castle, invented by David Millar, was originally named either Haunted Mirror Maze, or Vampire Mirror Maze. Your goal is to place the monsters shown into the grid using the number clues and positions of the double-sided mirrors in your line of sight. Each number shows how many monsters can be seen from that position.
The key to solving a Haunted Castle puzzle is to think along both directions from each line of sight. Here, the red arrows see nothing in the two cells their vision passes through, while the blue arrows see 2 monsters.
First, we know that neither monster is a zombie, because it would be visible from either direction.
Since ghosts can’t be seen directly, but are visible in a reflection, that means the cell on the left must contain a ghost – it would be visible from the 2, but not the 0.
Then, vampires can’t be seen in a mirror, but can be seen directly, so there must be one in the cell on the right.
This time, the line of sight passes through three empty cells, and there are 3 monsters visible from either direction, despite being reflected through two mirrors.
Since zombies are visible whether seen directly or in a reflection, they must all be zombies.
Here, we have a situation similar to the first step. Looking one way, we see nothing, so it must be a ghost before the mirrors, and a vampire after. This also fits with seeing 2 monsters in the other direction.
After that, we will have fulfilled both ghosts and both vampires that are in the grid, so the remaining cells must all be zombies, which you can verify by double-checking that the line of sight from the remaining clues matches the total number of squares each can see.
The completed puzzle.
