Straights: rules, tips and free puzzles online

Straights is a grid of white and black cells. No digit repeats in a row or column, and every compartment of white cells between black cells holds a run of consecutive digits, in any order. Play Straights puzzles online free here, on grids from 6×6 to 9×9.

It is often sold as Str8ts. Rows and columns don’t have to contain every digit, which makes it feel half sudoku, half Kakuro.

The rules

• Fill every white cell with a digit from 1 to N, where the grid is N×N (6×6 to 9×9 here).
• No digit appears twice in a row or column. Digits printed on black cells count too, so they can’t appear in white cells of the same row or column.
• Black cells split each row and column into compartments. Each compartment holds a set of consecutive digits, like 3, 4, 5, 6, in any order.
• Digits already in the grid are given clues.

How to start

Runs that must overlap

A compartment of k cells in an N-wide grid is a run starting anywhere from 1 to N − k + 1. When the compartment is more than half the width, every possible run shares some middle digits. In a 9×9, a five-cell compartment always contains 5, and a six-cell one always contains 4, 5 and 6.

One digit fixes a range

A placed digit limits how far the run can reach. In a three-cell compartment holding 9, the run can only be 7, 8, 9.

Rule digits out of the rest of the line

Once a compartment’s certain digits are known, no other compartment in that row or column can use them. Watch the column too: each white cell sits in a horizontal and a vertical compartment at once. Naked pairs and triples work along each row and column as usual, described in our solving techniques guide.

Common mistakes

• Forgetting the digits on black cells. They still block that digit in their row and column.
• Treating a whole row as one run. Only each compartment needs to be consecutive.
• Assuming every digit must appear in a row. With black cells in the way, some digits may be missing.

How the ranks scale difficulty

The same four ranks apply here as everywhere on the site. Lemma is a gentle warm-up, Proposition needs a real idea or two, Theorem is near-minimal with almost every clue load-bearing, and Conjecture is the sparsest of all, so expect to think hard.

Grids run from 6×6 at Lemma to 9×9 at Conjecture. Higher ranks have more black cells and fewer given digits.

There are 99,999 puzzles per rank, each with its own number, so you can replay one or share it. Every type also has a 30-puzzle collection that climbs from Lemma to Conjecture. Every puzzle is checked to have exactly one solution that you can reach by logic alone, with no guessing.

Keep exploring

• KakuroA numerical crossword: runs of distinct digits 1–9 that hit their sums.
• Renban SudokuPurple lines hold runs of consecutive digits, in any order.
• FutoshikiA Latin square with < and > signs between neighbouring cells.
• Solving techniquesSingles, pairs, cage arithmetic, line logic and Latin squares, all in one guide.
• All puzzle guidesEvery puzzle type on Hoot’s Puzzles, with rules and tips.