Guides → Nonogram
Nonogram Tips: Read Runs and Find Forced Cells
Each clue tells you the runs of filled cells in a row or column, in order, separated by at least one gap. The whole game is squeezing certainty out of that rule.
1. Start at the edges
Runs on the outer rows and columns are the easiest to reason about, and every solved edge cell gives you information for the row it crosses. Work the frame before the middle.
2. The overlap trick
For a single run, count its length from the left edge and mark that span, then count again from the right edge. Cells where the two spans overlap are filled for certain. A clue of 5 on a row of 10 always fills the middle cells 3–5 no matter where the run sits.
3. Mark empties too
Every row and column has a fixed total width. If the runs plus the required gaps between them cannot reach a cell, that cell is empty. Filling in these X marks is half the puzzle — empty cells shrink the space the runs can occupy and force the next placement.
4. Handle multiple runs
With two or more runs, slide the whole pattern left and right as a block. Any cell filled in every legal position is forced; any cell empty in every position is X. Long runs and long gaps make the pattern easier to pin down, so hunt rows where clue sizes are large.
5. Cross-referencing columns
Once a row’s cells are settled, the column clues do the heavy lifting. A partially filled column with clues like “3 1” often has only one run placement that matches the filled cells already there.
6. Never guess the picture
It is tempting to “draw” the pixel art, but one wrong cell corrupts every crossing row. Every ThinkyPlay Nonogram has a unique logical solution; when you are stuck, verify your X marks before you place anything new.