Is Trial and Error Allowed?
In short: guessing is never required in proper Sudoku. Every puzzle can be solved through logical deduction alone.
However, thinking "what if this number goes here?" during the learning process is itself a form of logical reasoning.
Guessing vs. Hypothesis Testing
❌ Guessing (Random)
Placing a number without any logical basis. Relying on luck — this is not how Sudoku is meant to be solved.
✅ Hypothesis Testing
"If X goes here, then Y must go there..." — logically working through consequences. If a contradiction arises, the alternative must be correct.
Try Before You Guess
- ✅ Write out all candidates using the memo feature
- ✅ Scan the board number by number
- ✅ Learn new techniques from the guides
- ✅ Use the hint feature to see what you are missing