Sufuku looks like Sudoku at first: a small grid, some numbers already filled in, and a logical challenge to complete the board. Then the twist changes everything: each number repeats as many times as its value. A 1 is alone. A 2 appears as a pair. A 3 appears as a trio. On a 6×6 board, that means every row has one 1, two 2s, and three 3s — and the same rule applies to every column and every region.
The core mechanic: count by value
If you’re trying Sufuku for the first time, forget the “one of each digit” habit from Sudoku. Instead, think of each group as a quota.
| Number | Copies required in each row, column, and region |
|---|---|
| 1 | Exactly 1 |
| 2 | Exactly 2 |
| 3 | Exactly 3 |
That adds up to 1 + 2 + 3 = 6 cells, which is exactly the size of a 6×6 row. Bigger boards use bigger numbers, but the logic is the same: a number’s value tells you how many copies of it belong in every group.
This also explains the phrase “numbers repeat by their value.” The number 2 is always a pair. The number 3 is always a triple. And 1 is the only number that stays a singleton.
Gold clues: trust them, count them
The gold numbers on the board are clues. They’re not special values — they follow the exact same quota rules. Their job is to give you a starting point.
When you look at a row with clue numbers, count how many 1s, 2s, and 3s are already present. Compare that to the quota.
For example, if a row already contains one 1 and two 2s, then you know the row’s remaining empty cells must be 3s — because the row’s quota allows exactly three 3s, and you haven’t placed any yet.
A simple walkthrough for your first puzzle
Try this method on a practice board before jumping into the daily puzzle.
- Pick the row, column, or region with the most gold clues. The more clues you have, the fewer missing numbers you have to figure out.
- Count what’s already there. Write down how many 1s, 2s, and 3s you see. Subtract those from the required amounts to find your remaining quotas.
- Check a possible placement against all three groups at once. If you want to place a 3, confirm that the row still needs 3s, the column still needs 3s, and the region still needs 3s.
- Place the number, then update your mental counts. Every placement fills one copy in its row, one copy in its column, and one copy in its region.
- If you make a mistake, undo and reconsider. When a number appears more times than its value, it’s a mistake. That includes placing a third 2 in a group, or a fourth 3 in a group.
The trick is to remember that a valid number can’t just fit one quota. It has to fit all three.
Don’t solve row by row alone. A 3 that is still missing in a row may already be full in that column or region. Always check the other two groups before committing.
Why this feels harder than Sudoku
In Sudoku, placing a number removes that number from the rest of the row, column, and box. In Sufuku, placing a 2 doesn’t remove 2s — it leaves room for one more 2 in that group. You’re not just working with “which numbers are missing.” You’re tracking how many copies of each number are still allowed.
That three-way counting is the real skill. By keeping each row, column, and region within its one-or-two-or-three quota, you gradually narrow the board down to the puzzle’s single solution.
FAQ
Is the rule exactly the same for columns and regions? Yes. Every row, every column, and every region follows the same value-based repetition rule.
What happens if I place too many of a number? The site marks it as a mistake. If a number appears more times than its value, the placement is wrong.
Are gold clues changeable? No. Gold numbers are fixed clues. They’re your safe starting points.
Once the quota logic clicks, Sufuku becomes less about guessing and more about balancing groups. The one simple rule — repeat each number by its value — is the whole puzzle.
