How to Read the Number Clues

Understanding exactly what "3 1" means.

Each number in a clue is the count of consecutive filled cells. "3 1" means there is a 3-cell block and a 1-cell block in that order, with at least one empty cell between them.

Add all the clue numbers and then add (number of blocks − 1) to get the minimum length that line takes up. The closer this value is to the length of the line, the more the placement is constrained.

If there is a single clue whose number equals the line's length, that whole line is filled. If the clue is 0, that whole line is empty. Handling these extremes first opens up your first clues.