Str8ts
- Category
- Brain
- Players
- 1
- Controls
- Tap
- Runs
- Consecutive
- Loads
- No download
Controls
| Tap a white cell | Select it. |
| Tap a number | Place it. |
| Tap ✕ | Clear the cell. |
Next up
| Tap a white cell | Select it. |
| Tap a number | Place it. |
| Tap ✕ | Clear the cell. |
Str8ts takes the sudoku idea and adds a twist. Black squares break each row and column into short white runs, and every run must contain a set of consecutive numbers — in any order. On top of that, no number may repeat anywhere in a row or column.
The consecutive rule is far more restrictive than it looks. A run of three containing a one and a five is immediately impossible, and spotting those contradictions early is most of the solving. It is a genuinely different feel from ordinary sudoku despite the family resemblance.
Check the spread of each run. A run of three cells can only hold numbers within a span of three, so a one and a four in the same run is already a contradiction.
Start with the shortest runs. A run of two has very few possibilities once one cell is filled, since the other must be exactly one higher or lower.
Use the row and column rule as a second pass. The consecutive constraint usually generates candidates and the no-repeat rule then eliminates most of them.
Look at what a placement forbids elsewhere. Putting a five in one run often removes it from a crossing run, which can collapse that run to a single arrangement.
A group of white cells between black squares, in a row or column.
No, only consecutive as a set. A run holding 4, 2, 3 is fine.
No, the sudoku rule still applies across the whole row and column.
Yes. The black squares are placed first and the grid is filled by a search that enforces both rules.
No. Str8ts runs entirely inside this page, so it starts the moment the page opens. There is nothing to download, no plugin, and no account to create.