Types of Sudoku: 12 Popular Variations Explained

Once classic Sudoku starts feeling routine, there's a whole world of variations waiting. The types of Sudoku below all share the same DNA, which is to fill a grid so digits don't repeat, but each one adds a twist that changes how you solve. Some bolt on arithmetic, some bend the shapes of the regions, some glue several grids together. Here are twelve worth knowing, from the gentle tweaks to the genuinely brutal, with links to play the ones we make.

Classic Sudoku (the baseline)

The one everyone knows: a 9x9 grid, nine 3x3 boxes, digits 1 to 9 with no repeats in any row, column, or box. Every variation below is a departure from this, so it's the reference point. If you're still getting comfortable, the how to solve Sudoku guide covers the fundamentals, and you can play classic Sudoku at five difficulty levels.

Killer Sudoku

Classic rules plus arithmetic. The grid is divided into dotted "cages," each with a small target sum, and the digits inside a cage must add up to that total without repeating. You get few or no starting clues, so the sums are the clues. Killer rewards knowing your combinations, which sets of digits can make a given total in a given number of cells. It's a favorite for a reason. Play Killer Sudoku.

Jigsaw Sudoku (Squiggly Sudoku)

Same 9x9 grid and the same 1-to-9 rule, but the nine regions aren't tidy 3x3 boxes. They're irregular, interlocking shapes. This breaks a lot of your scanning instincts, because the "box" you're used to is now a squiggle that snakes across rows and columns. It also goes by irregular Sudoku or nonomino Sudoku. Surprisingly fresh once you adjust. Play Jigsaw Sudoku.

Samurai Sudoku

Five overlapping 9x9 grids arranged in an X, sharing their corner boxes. Solving one grid feeds clues into the next through the shared regions, so you bounce between all five. It's less about new techniques and more about scale and stamina. A single Samurai can take as long as several classic puzzles. Play Samurai Sudoku.

KenKen

A cousin rather than a strict Sudoku, but it belongs here. KenKen uses a Latin-square grid (each number once per row and column) divided into cages, where each cage shows a target and an operation: add, subtract, multiply, or divide. You combine arithmetic with placement logic, and grids range from a gentle 3x3 up to a meaty 7x7. Great if you like the math angle of Killer but want something more compact. Play KenKen.

Futoshiki

Another Latin-square puzzle with a twist: greater-than and less-than signs sit between some cells, telling you which neighbor is bigger. You seed the grid from those inequality chains, then fill the rest by elimination. Smaller grids than Sudoku, but the comparison logic gives it a distinct feel. Play Futoshiki.

Mini Sudoku (4x4 and 6x6)

Sudoku shrunk down. A 4x4 uses digits 1 to 4 in 2x2 boxes; a 6x6 uses 1 to 6 in 2x3 boxes. The rules are identical, just smaller, which makes these the perfect on-ramp for kids or anyone learning. Quick to solve and hard to get wrong.

Diagonal Sudoku (Sudoku X)

Classic rules, plus the two main diagonals must each also contain 1 to 9 with no repeats. Those two extra constraints give you more to work with and create satisfying deductions right through the center of the grid. A small change that solves quite differently.

Hyper Sudoku (Windoku)

Standard 9x9, but with four extra shaded 3x3 regions floating inside the grid, each of which must also hold 1 to 9. The overlapping constraints make for tighter, more interconnected logic than classic. A good next step if you want more bite without changing the digits.

Even-Odd Sudoku

Classic rules with some cells shaded to mark them as even-only or odd-only. The shading narrows candidates before you even start, which opens up lines of reasoning based purely on parity. A subtle but genuinely different solving experience.

Color and consecutive variants

Plenty of variations swap the constraint flavor. Color Sudoku replaces digits with colors (same logic, friendlier for young solvers), while consecutive Sudoku marks where adjacent cells differ by one. These are mostly re-skins or light add-ons to the core rule, but they keep things fresh.

Sudoku for kids

Worth calling out as its own category. Smaller grids, addition-and-counting framing, and pictures or colors instead of digits make Sudoku approachable for early learners. The logic muscle it builds transfers straight to the full game later.

Which variation should you try next?

A rough guide based on what you enjoy:

• Like arithmetic? Go Killer Sudoku or KenKen.
• Want your scanning instincts challenged? Jigsaw Sudoku.
• Craving a marathon? Samurai Sudoku.
• Prefer something compact and logical? Futoshiki.

Whichever you pick, the core skill carries over. The techniques in the Sudoku strategy guide, scanning, singles, and pairs, apply to almost every variation on this list, just with an extra rule layered on top. Learn them once, and the whole family opens up.