Meet Hyper Sudoku

Hyper Sudoku is classic Sudoku with four extra rooms. Same 9×9 grid, same digits, same rows and columns and boxes — plus four additional 3×3 regions tucked inside the grid, each obeying the same uniqueness rule as a standard box. If classic Sudoku has nine boxes, Hyper Sudoku has thirteen. You'll also see it called Windoku, which is the older name and the one preferred in continental Europe.

It's a denser puzzle than classic, and a less radical change than Sudoku X. Most people who like classic Sudoku find Hyper Sudoku immediately likeable.

What the hyper regions do for you

The four extra regions are positioned in the middle of each grid quadrant — not touching each other, not touching the grid edges. Every cell inside a hyper region belongs to four units instead of three: a row, a column, a 3×3 box, and a hyper region. Those four-unit cells are where most of the variant's character lives. A placement in one of them constrains more of the board than the same placement in a classic Sudoku would, because it has more units to broadcast through.

The rest of the board — the 45 cells outside any hyper region — plays exactly as it would in a classic Sudoku. So roughly half the grid feels familiar and half feels slightly tighter.

Is it for you?

Most people who enjoy classic Sudoku enjoy Hyper Sudoku. The skills transfer cleanly. The technique vocabulary is unchanged — naked singles, hidden singles, pairs, locked candidates, all the standard moves work identically. The hyper regions just give those moves a fourth unit to fire on for the cells that sit inside one.

The variant is friendlier to a classic solver than to a Sudoku X solver, in a small way: Sudoku X asks you to look at seventeen new cells differently, but the new unit (the diagonal) is novel-shaped. Hyper Sudoku asks you to look at 36 new cells differently, but the new units are the same shape as the standard boxes you already scan. You already know how to scan a 3×3 region. Hyper just adds four more of them.

The solvers who don't take to it tend to be the ones who like classic Sudoku precisely because of its visual cleanness — the unshaded grid, the simple tripartite unit structure. The shaded hyper regions add visual texture, and for some solvers that texture reads as noise. Most don't mind; some do.

A small experiment

The honest test is to play one. Our easy Hyper Sudoku puzzles take about the same time as easy classic puzzles, and the hyper regions are marked with a soft coral outline on the board so the geometry is visible without having to memorise it.

The variant has been a quiet fixture of puzzle publishing for thirty-odd years — long enough that there's a stable community of solvers who prefer it to classic, but never famous enough to have had its own meme moment. It's one of the puzzles that rewards a bit of patience: the first puzzle teaches you the geometry, the second teaches you how the regions help, and from the third onward the variant starts to feel like its own thing rather than classic-with-decoration. Try one and see.