Number Loom: narrow the candidates before choosing a number
Use a row with two gaps to separate a forced entry from a plausible guess, then bring the box constraints into the same reasoning.
Worked examples use the Standard board unless a different size is stated. Hard and Expert may change the board dimensions or amount of information to track.
A square belongs to three groups
An empty square in Number Loom has a row, a column and an outlined box. A number is only a candidate if none of those three groups already contains it. Watching just the row is an easy way to make an entry that looks tidy but contradicts the rest of the board. Start by identifying the three groups before trying any number.
In Hard mode, the board contains numbers 1 to 6 and its boxes are two rows tall and three columns wide. That rectangle matters: the neighbouring box does not necessarily begin where your eye expects a square box. Use the heavier boundaries as a reference instead of assuming every block is three by three.
Work a row with two gaps
Imagine a six-square row reading 1, blank, 3, blank, 5, 6. The missing numbers are 2 and 4. The row alone does not decide which gap receives which number. Now suppose the column through the second square already contains 4 elsewhere. The second square cannot also be 4, so it must be 2. The remaining gap in that row must then be 4.
The important part is the reason, not the order in which the values were entered. The first decision combined information from a row and a column. The second decision followed from the completed row. If the column had contained neither candidate, the same row would not have justified either entry yet.
Use a box when the row does not decide
Apply the same missing-number question to an outlined box. List the values already present, then consider the empty squares one at a time. A number that is missing from the box may still be barred from a particular square by that square’s row or column. If only one square remains possible for that number within the box, you have a concrete reason to place it.
Keep candidate notes separate from committed entries while you reason. Two empty squares may both allow 2 and 4. That observation does not decide which square gets 2; it records a restriction that later information may resolve. Filling one simply to keep moving turns a useful restriction into an unsupported guess.
Read the conflict markers carefully
The board highlights duplicate numbers in a row, column or box. That feedback catches an immediate contradiction. It does not mean every unmarked entry is correct. A mistaken number can leave all three groups temporarily free of duplicates while making a later square impossible. The puzzle’s checked unique solution does not make each locally legal move a forced move.
When an experiment becomes unclear, use Undo to return through the entries you made. Restart keeps the same starting clues, which lets you revisit the reasoning without changing the problem. Before trying Expert’s larger board, practise explaining each entry as a constraint shared by its row, column and box. A sentence you can check is more useful than a quick guess you cannot reconstruct.
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