Str8ts

Str8ts is a number puzzle created by German puzzle inventor and author Jurgen Reiche. It uses a Sudoku-like grid divided by black cells, but white runs follow a consecutive rule. A run can contain 2, 3, 4, or 5 numbers with no repeats, and its values must form an unbroken sequence in any order. Black cells may show clues that restrict a neighboring white run. Rows and columns supply the wider deduction. Fill the Str8ts practice board above.

1. Open Str8ts and read the clues before placing anything. Identify the white runs between black cells in each row and column.
2. For a run of length N, list a consecutive set of N values that fits the row and column limits.
3. Click a white cell to cycle through its candidate values. Black cells stay blocked.
4. Check both directions after every entry. A value can fit its horizontal run but fail its vertical run.
5. Complete each run with consecutive, nonrepeating values and satisfy all displayed clues.
6. Use the restart button for a fresh board. Your current moves stay in the browser while you solve, so you can pause and return to the same deduction.

• A white run contains consecutive values with no duplicate.
• Rows and columns cannot repeat a value in their usable white cells.
• Black cells divide runs and may carry a clue value.
• Every white cell receives a value from the board's number range.
• A completed run may be ordered in different ways, as long as the set is consecutive.
• A completed board must satisfy every clue at the same time. One correct-looking row does not finish the puzzle if another constraint remains unresolved.
• This version runs locally in your browser, with no account or download required.

• Start with a run whose length nearly fills the number range. A five-cell run in a 5 by 5 board has only one possible set.
• Use the smallest and largest values as anchors. They limit which consecutive set can fit around them.
• Treat black clue numbers as row and column restrictions, not as part of a white run.
• If a run can be 2-3-4 or 3-4-5, inspect the crossing column to remove one set.
• Remember that consecutive does not mean ascending. A valid run may read 4, 2, 3 only if the complete set is 2, 3, 4 and other constraints allow it.
• Mark certain information first. A forced cell removes more candidates than a guess and gives you a reliable next step.
• When two candidates remain, compare both against the row, column, region, and neighbor restrictions before committing.
• Keep a small mental record of what a clue still needs. Revisiting that count after each placement often reveals a move that was hidden at the start.

• Classic Str8ts: The standard format combines black separators, optional black-cell clues, consecutive white runs, and no repeats in rows or columns.
• Daily Str8ts: Daily versions keep the same rules while changing the fixed clue layout, giving regular players a new deduction set each day.

• The black cells make the grid easy to scan.
• Consecutive sets give stronger clues than ordinary Latin-square filling.
• Crossing rows and columns create useful confirmation.
• The rules feel familiar to Sudoku players while changing the deductions.
• Runs make progress visible across the whole board.

Play Str8ts online for free on Clasica Games. The puzzle opens directly on this page, touch controls work on small screens, and the restart control deals another practice position. Start with a clue you understand, make one careful move, and let the board reveal the next question.

Str8ts rewards careful reading and a steady chain of deductions. Start with the clearest clue, check its neighbors, and keep the goal visible. When you want a short logic break, play Str8ts online free in your browser and try the board above.

• Str8ts official website
• Jurgen Reiche puzzle information