Nonogram rules and strategy
A nonogram asks one thing: fill the grid from the clues and a picture appears. The rules take a minute; the skill is in the order you solve it.
How to play
- 1
Read the clues
The numbers beside each row and above each column are the lengths of the consecutive filled blocks in that line, in order, with at least one empty cell between them.
- 2
Fill and mark
Drag to fill several cells at once. Tapping one cell cycles filled / empty / unknown. The mark-empty mode lets you x out cells that must be blank so you stop re-checking them.
- 3
Reveal the picture
Fill exactly the right cells and the puzzle is solved — the shape you painted is the hidden picture.
Solving tactics
- Overlap: when a block is longer than half of the remaining space, some of its cells are always filled.
- Edges first: lines that touch the border are the most constrained.
- Eliminate: mark the cells that must be empty early; the smaller space pins down the rest.
- Switch direction: when a row stalls, work the columns. Alternating is much faster.
Picking a size
5×5 is the tutorial size, 10×10 is the classic, and 15×15 needs patience. The 10 puzzles here are ordered by size.
Origins
Nonograms were invented in Japan in the 1980s as Oekaki Logic — drawing logic. The rules are minimal, yet the grids can render detailed pixel art. Nintendo's Mario's Picross (1995) popularised them, and they are now one of the most common logic puzzles.