How to play sudoku
Sudoku in Octopuzzle is the classic 9×9 puzzle, with no daily limit. Choose Easy, Medium or Hard, fill the grid with the digits 1 to 9, and start another as soon as you finish. Every puzzle is made on your phone, so it works with no connection.
The rules
- 1
Fill every empty cell
Put a digit from 1 to 9 in every empty cell of the 9×9 grid. The digits already on the board are fixed.
- 2
Each row has 1 to 9 once
No digit can appear twice in the same row.
- 3
Each column has 1 to 9 once
No digit can appear twice in the same column.
- 4
Each 3×3 box has 1 to 9 once
Thick lines split the grid into nine 3×3 boxes, and each box holds every digit once.
- 5
There is one answer
Every puzzle has exactly one solution, at every level.
- 6
Use notes, undo and hints
Tap a cell, then a digit. Turn on Notes to pencil in candidates. Digits that clash are highlighted, Undo steps back, and a hint fills in a cell with the right digit.
A puzzle in progress
Tips for solving
- Find the singles first. A cell with only one possible digit is a naked single. A digit with only one possible cell in a row, column or box is a hidden single. Easy puzzles need nothing else.
- Scan one digit at a time across the whole board. Following every 5, then every 6, finds hidden singles faster than staring at one cell.
- Pointing: if a digit's only spots in a box all sit in one row, it can't appear anywhere else in that row. The same works for columns.
- Pairs: if two cells in a row, column or box can only hold the same two digits, no other cell in that line can hold either of them.
- On Hard, keep full notes. These puzzles need more than singles, pointing and pairs, and the next step is usually visible only in the candidates.
Levels and records
Sudoku is an Unlimited game, so it has no daily puzzle and no points. It keeps its own record on your phone for each level: games played, solve rate, and your best and average times.
Easy puzzles start with at least 36 digits and can be solved with singles alone. Medium puzzles also need pointing or pairs. Hard puzzles need more than those.
| Easy | Singles only |
|---|---|
| Medium | Pointing and pairs |
| Hard | Beyond pairs |
Streaks
Sudoku doesn't count toward your streak, groups or leagues, so you can play as many as you like without changing them.
Your streak comes from the three daily puzzles: Word, Number and Logic. Play any one of them to the end each day to keep it going.
Questions
Get the app
Word, Number and Logic arrive fresh every day, and Unlimited has classic Sudoku whenever you want more. Free, no ads, and it plays offline. Octopuzzle is coming to iPhone first, with Android planned.
