Castle Wall

• Loops
• Connections
• Regions

Draw one closed wall: white clues stay inside, black clues outside, and each arrow counts wall crossings in its direction.

1. Draw one orthogonal closed loop through centres of empty cells, with no crossings or branches and never through a clue cell.
2. White clues must be inside the loop and black clues outside.
3. A numbered arrow tells how many wall segments its ray crosses in the indicated direction.

• Look for nearby inside and outside clues: the wall must separate them while matching each arrow’s crossing count.
• Nearby white and black clues force the wall to separate them.
• A zero arrow rules out every crossing along its ray.
• Do not close a small loop: the finished wall must be a single loop.

We do not yet have a sufficiently verified account of this game’s origins. Rather than guess, we avoid attributing a date or creator without reliable evidence.

• Nearby white and black clues force the wall to separate them.
• A zero arrow rules out every crossing along its ray.
• Do not close a small loop: the finished wall must be a single loop.

• Where should I begin? Look for nearby inside and outside clues: the wall must separate them while matching each arrow’s crossing count.
• What makes this game different? A numbered arrow tells how many wall segments its ray crosses in the indicated direction.