View the example grid
Two puzzles with the same number of empty cells can call for different reasoning. A grid full of direct singles is a different task from one that first needs a candidate pattern.
The required move matters
Unisu’s 16 levels follow the techniques needed to solve its puzzles. Early levels begin with Full House and singles. Later ones introduce Locked Candidates, pairs, wings and eventually chains. A level name is not a universal measure across other apps or newspaper puzzles.
A comparison
If a row is missing only 7, you can place it directly. An X-Wing asks you to examine one digit across two rows and two columns. A puzzle can therefore demand more reasoning even when its next certain step only removes a candidate.
Pick a starting point
Choose a level whose techniques you can follow. When a method is new, read its introduction and practice in the app. A harder label matters less than understanding the move you made.
Frequently asked questions
Do fewer givens always mean a harder Sudoku?
No. Difficulty also depends on the reasoning required. The number of empty cells does not describe the solving path by itself.
What are Unisu’s 16 levels based on?
The techniques needed to progress. Direct steps come first, followed by more involved candidate patterns and chains.
Can I compare these levels directly with another app?
Not reliably. Apps and newspapers can use the same difficulty label for different demands.
Should I choose a level only by my solving time?
Focus on whether you can follow the reasoning. Time also depends on experience and your search routine.
How can I prepare for a harder level?
Study the newly required technique and try its reasoning on an example. Then look for it in an appropriate puzzle.
Keep practicing in Unisu
Download Unisu for iPhone or Android. Solve a puzzle or work through a guided lesson on the technique.
