The rules of a standard monochrome Nonogram are simple: fill cells so that the consecutive filled blocks in every row and every column match that line's clues exactly, in the stated order, with at least one empty cell between neighboring blocks.
Every cell must satisfy its row and column at the same time. The challenge is not understanding the rules; it is proving where the blocks must go.
The rules at a glance
For every row and column:
- each clue number represents one consecutive block of filled cells;
- the size of the block must equal the clue number exactly;
- multiple clue blocks must appear in the same order as the clues;
- consecutive monochrome blocks must have at least one empty cell between them;
- cells outside those blocks are empty;
- the final cell states must satisfy both the row clue and the column clue.
Those six statements describe the standard puzzle.
Solving techniques such as overlap, edge anchoring, gap elimination, and contradiction reasoning do not add new rules. They are methods for finding consequences of these constraints.
Rule 1: Each clue number is one filled block
A clue of:
4
means the line contains one block of four consecutive filled cells.
The block cannot contain three cells and it cannot contain five. Its length is exactly four.
A legal completed 7-cell line might therefore be:
×■■■■××
where ■ is filled and × is empty.
The exact position may differ, but the final line must contain exactly one four-cell block.
Rule 2: Multiple clues preserve their order
A clue sequence such as:
2 3
does not simply mean “five filled cells somewhere.”
It means:
- first, a block of exactly 2 filled cells;
- later, a block of exactly 3 filled cells.
The 2-block must come before the 3-block when reading left to right across a row or top to bottom down a column.
You cannot swap the two blocks unless the clue sequence itself is reversed.
This order constraint becomes increasingly powerful when known filled and empty cells divide a line into smaller regions.
Rule 3: Neighboring monochrome blocks need a gap
Two different clue numbers must describe two distinct blocks.
For clue:
2 2
the two 2-blocks cannot touch.
This would be invalid:
■■■■
because it forms one block of four cells.
There must be at least one empty cell between the blocks:
■■×■■
That separating empty cell is a mandatory gap.
The gap may be larger than one cell. The rule only requires at least one confirmed empty position between consecutive monochrome blocks.
Rule 4: Cells outside the clue blocks are empty
A completed line contains exactly the blocks described by its clues and no additional filled cells.
If a 7-cell line has clue:
3
and the three-cell block is known to occupy cells 3–5, then cells 1, 2, 6, and 7 are empty.
You cannot add an isolated filled cell elsewhere in the line. Doing so would create another block that is not represented by the clue.
This is why identifying a completed block is useful: once a block has reached its clue length and its identity is known, cells that would extend it can often be marked empty.
Rule 5: Every cell belongs to a row and a column
A row solution is not valid in isolation.
Every cell sits at the intersection of one row and one column. If a row forces a cell filled, the crossing column must also be able to include that filled cell while satisfying its own clues.
Likewise, a cell proven empty from a column becomes an unavailable position in the row.
The whole puzzle is solved only when all row and column clue sequences agree on every cell.
This two-direction constraint is what makes Nonograms more than a collection of separate line puzzles.
Rule 6: Unknown is not the same as empty
While solving, a cell can be:
- filled — proven to belong to a block;
- empty — proven not to belong to any block;
- unknown — not yet determined.
Only filled and empty are final solution states. Unknown is a temporary solving state.
A common beginner mistake is to treat an unfilled cell as if it were already confirmed empty. Until logic proves the cell empty, it must remain available to any clue block that can legally reach it.
Many interfaces use an X to record a confirmed empty cell, but the visual symbol does not change the rule.
How are empty lines represented?
If a row or column contains no filled cells, its solution is entirely empty.
Different puzzle formats may represent that clue in different ways. Some show 0; others leave the clue area blank or use another explicit convention.
The logical meaning is the same: there are no filled blocks in that line, so every cell is empty.
When reading a specific interface or printed puzzle, follow its stated notation rather than assuming that one display convention is universal.
A complete-line example
Consider a 6-cell line with clues:
3 2
The minimum required space is:
- 3 cells for the first block;
- 1 mandatory empty cell;
- 2 cells for the second block.
That uses all 6 cells, so there is only one legal arrangement:
■■■×■■
This is an exact-fit line. The rule itself is simply that the blocks must fit in order with the required separator; the fact that every position becomes forced is a solving deduction.
What counts as a valid completed line?
A line is valid when all of the following are true:
- every clue has one matching filled block;
- every matching block has the correct length;
- the blocks appear in clue order;
- neighboring blocks are separated by at least one empty cell;
- there are no extra filled blocks;
- every cell has a final filled or empty state.
A line that satisfies only the correct number of filled cells is not necessarily valid.
For example, clues 2 2 require four filled cells in total, but ■■■■ is still invalid because those cells form one block instead of two.
What counts as a valid completed grid?
A completed grid is valid when:
- every row matches its clue sequence;
- every column matches its clue sequence;
- no cell is left unknown.
A grid can look like a recognizable picture and still be invalid if even one row or column violates its clue.
Conversely, the intended logical solution does not need to resemble anything obvious while you are solving it. The constraints are what determine validity.
Is a unique solution one of the rules?
Not exactly.
The line rules define what a valid solution must look like. Uniqueness asks how many complete grids satisfy all those rules for a particular clue set.
A well-constructed published Nonogram is normally intended to have one solution. But arbitrary clues can produce:
- one solution;
- multiple solutions;
- or no solution at all.
That is why puzzle generation and validation are separate topics from the basic rule set.
Is guessing against the rules?
A guess may accidentally lead to the correct solution, but it is not a logical deduction.
When VeyraPlay says a cell is forced, it means every valid possibility under the current constraints gives that cell the same state.
Standard solving aims to find such forced information instead of choosing an unresolved possibility because it seems likely.
More advanced puzzles may require deeper reasoning than simple line scanning, but the goal remains the same: justify the state from constraints.
Does this rule set include Color Nonograms?
No. This Guide covers standard monochrome Nonograms only.
Color Nonograms introduce color information and different adjacency behavior between blocks of different colors. VeyraPlay treats them as a separate sibling game and editorial vertical.
FAQ
Can two Nonogram blocks touch?
Not in a standard monochrome Nonogram. Separate clue blocks require at least one empty cell between them.
Can there be more empty cells than the minimum gap?
Yes. A mandatory gap has a minimum size of one cell, but the actual empty space between blocks can be larger.
Do the clues give exact positions?
No. They give block lengths and order. You determine the positions from all current row and column constraints.
Can a line contain extra filled cells after all clues are satisfied?
No. Any filled cell must belong to one of the blocks represented by the clue sequence.
Does every line have a clue?
Every line has a logical clue sequence, even when it contains no filled blocks. How an empty clue sequence is displayed depends on the puzzle format.
Do row clues matter more than column clues?
No. Rows and columns impose equal constraints. A correct final cell state must satisfy both directions.
What to learn next
Next, learn How to Play Nonograms for the practical solve loop, or How to Read Nonogram Clues for a deeper look at clue sequences and minimum space.