DeduceOrder

taxcubesu

About this game

DeduceOrder is a calm, single-player logic puzzle built on one simple rule: every row, every column and every box region must contain each number exactly once.

Start from a partially filled board, remove the impossible candidates step by step, and complete the whole grid through pure reasoning. There is no timer pressure and no guessing required.

GAME MODES
- Beginner: 6x6 boards with many starting clues to learn the basics.
- Intermediate: 9x9 boards with a balanced set of clues.
- Expert: 9x9 boards with fewer clues and deeper candidate chains.
- Daily Challenge: a fresh verified puzzle chosen from the built-in library by your local date, fully offline.
- Interactive tutorial: a guided 4x4 demo that teaches unique candidates, row and column elimination, and region elimination with real steps.

PUZZLE QUALITY
Every level is verified to have exactly one solution and to be solvable using logical elimination alone. No guessing, no luck. Difficulty grows from fewer starting clues, richer candidate intersections and changing solution patterns.

THINKING TOOLS
- Pencil candidates: note possible numbers in any empty cell without committing to an answer.
- Hints: up to three hints per game, each explaining a verifiable deduction step (unique candidate, row/column elimination or region elimination).
- Check: verify the board and flag duplicated numbers without revealing correct answers.
- Conflict marking: duplicated numbers are marked with both a distinct shape and a clear signal, so it never relies on color alone.

CONTROL AND COMFORT
- Undo, redo and erase for every value and candidate change.
- Large one-handed touch targets on the board and keypad.
- Automatic saving: your board, candidates, timer and undo history are saved whenever you pause, leave or switch apps, and resume exactly where you left off without double-counting time.
- Clear whole board reset with a confirmation step.
- Light and dark themes, optional sound effects, animations and assist highlights.

PROGRESS AND RECORDS
- Chapter completion tracking for Beginner, Intermediate and Expert.
- Personal fastest times for 6x6 and 9x9 boards.
- No-hint completion records for players who solve boards purely by deduction.
- Daily streak tracking for consecutive challenge completions.
- Local achievements unlocked as you play.

PRIVACY AND OFFLINE
DeduceOrder works entirely offline. No account, no ads, no purchases, no leaderboards and no network connection are required. All progress is stored locally on your device only.