Tackling Big Puzzles (15×15, 20×20)

Breaking down complex grids systematically.

Big puzzles overwhelm you if you try to see everything at once. First sweep every line and fill in all the cells confirmed by overlap, then tackle the lines with large clue sums and the edges first.

The rhythm of rescanning the crossing lines each time a confirmed cell appears is crucial. A newly filled cell and a new X often open up overlap or block splitting on another line.

Use the bold dividing lines drawn every 5 cells like coordinates to line clues up against cells more easily. The bigger the puzzle, the more carefully you should mark X to manage the possibilities.