Sudoku-Style Games: What Variants Trade for Clues
Sudoku has one rule and many games — and the reason is not the generosity of variant authors. Every sudoku variant answers the same question: what replaces the clues? The classic hands you ready digits and asks you to finish the rest. Design starts after that: take clues away, and something has to take their place — otherwise the puzzle collapses into guessing.
That's how the families appear. "Killer Sudoku" changes the currency itself: instead of clues, the grid is cut into zones with sums, and arithmetic joins placement logic — a 17 in the corner means not "digits were here" but "a combination is hidden here that you still have to compute." "Thermo Sudoku" draws thermometers on the field: digits only grow along them, and one long thermometer holds half the grid better than a dozen scattered clues. "X-Sums Sudoku" pushes the sums outside the border — they read along the diagonals, so you think about the edges first and the middle later.
The other branch changes shape, not clues. "Sudoku X" adds two diagonals to rows, columns and blocks where repeats are also forbidden: a nine or a five on a diagonal now has a second employer. "Odd-Even Sudoku" marks cells — a circle demands an even digit, a square an odd one — and the grid starts hinting exactly where the classic stays silent.
The third branch changes size. "Mini Sudoku" squeezes the grid to 6×6 with 2×3 boxes: same rule, a round takes five minutes instead of half an hour, and mistakes surface sooner — a small grid leaves nowhere for a wrong digit to hide for half an hour.
What matters here: variants don't rank from easy to hard as rungs of one ladder. "Mini" is smaller but punishes faster. "Killer" is heavier on tools, yet its sum zones point directions more strongly than an empty classic. The right way to choose is not by a difficulty number but by which instrument you enjoy holding: arithmetic, thermometers, diagonals, or bare empty cells.
The full list with a note on every variant lives on the Sudoku Games collection page. A comfortable way up:
- Sudoku — classic 9×9, nothing extra
- Mini Sudoku — 6×6, a five-minute round
- Sudoku X — two diagonals added
- Odd-Even Sudoku — marks instead of silence
- Killer Sudoku — sum zones instead of clues
- Thermo Sudoku — digits only grow along thermometers
- X-Sums Sudoku — sums carried outside the border