Hard (15×15)

Grid Size: 15 × 15

For when you want to practice intermediate techniques in real games.

Hard is a 15×15 grid that calls for techniques like extending from the edge and the forcing chain. Careful X management becomes the key to solving it.

Because you must read information passing across several lines, a wide field of view and the habit of rescanning are important.

  • Use an X near the edge to push back where the first block starts.
  • Use the bold lines every 5 cells as coordinates to line clues up with cells.

▶ Start at this difficulty