Every Sudoku variant explained: Killer, Mini, and the rest

Classic Sudoku

Given numbers, no arithmetic, pure scanning. Everything else on this list is this game with something added, so it is worth being comfortable here first.

Mini Sudoku, four by four

The same rules on a four by four grid with two by two boxes, using only 1 to 4. A puzzle takes two or three minutes, which makes it the right size for a child or for learning the idea of a unit.

Killer Sudoku

No givens at all. Instead the grid is covered in cages, each with a total, and no digit repeats inside a cage. You start by working out which combinations a total allows, then switch to ordinary scanning once digits appear.

It is the biggest step up on this list, and the most rewarding once the first cages fall.

Killer Sudoku four by four

Cages and sums on the small grid. Totals are tiny, the combinations are obvious, and it teaches cage logic in about two minutes.

Variants you will meet elsewhere

• Jigsaw: the boxes are irregular shapes rather than three by three blocks.
• Diagonal, sometimes called X Sudoku: both long diagonals must also hold 1 to 9.
• Hyper: four extra shaded boxes overlap the normal ones.
• Samurai: five overlapping grids sharing corner boxes, which is mostly an endurance test.

Where to go next

If plain Sudoku has stopped resisting, Killer is the obvious move, because it changes how you open a puzzle rather than just making the scanning harder.

If you want harder scanning instead, the difficulty levels on classic Sudoku go further than most people try.