Sudoku – we love it. It’s been a staple of puzzle pages for decades. Puzzle aficionados have been enjoying the game for even longer. The classic 9x9 grid is just the beginning though. For those who crave more complexity and a fresh twist on the beloved puzzle, there are numerous exciting variations and spin-offs to explore.
One of the most popular is 16x16 Sudoku. This larger grid tests even the most seasoned players with its intricate patterns and numerous possibilities.
Let’s start with a quick recap of the rules of regular Sudoku: in a given grid, every row, column, and block must contain all the digits from 1 to 9 once, and only once:
16x16 Sudoku is the simplest variant – we take a regular grid and supersize it to 16 cells by 16 cells, instead of 9x9. That means every row, column and block must contain the numbers 1-16 once and only once.
Or does it?
Actually, there are two slightly different varieties of 16x16 Sudoku. One version uses decimal numbers (1-16) and the other version uses numbers and letters such that there’s only ever one ‘digit’ in any cell. In other words, some 16x16 Sudoku puzzle variants use the symbols: 1,2,3,4,5,6,7,8,9,A,B,C,D,E,F,G
By the way, all the 16x16 puzzles we publish at Puzzle Genius use numbers 1-16, because we’re purists at heart.
If Sudoku is so great (and it really is), then why did anyone want to make it bigger? Well, why does anyone want to make anything bigger? You can’t have too much of a good thing, as they say. Then again, they also say that bigger isn’t always better. Who are ‘they’ anyway, and should we be paying them any attention?
In the case of Sudoku, there’s a very simple and compelling reason to supersize the grid: bigger grids can make for harder puzzles that take longer to solve.
That’s not to say that all 16x16 Sudokus are tougher than their regular 9x9 cousins. It’s perfectly possible to make easy puzzles. But having more numbers does give greater scope for increased difficulty. Not just because there are more numbers to find, but also because a lot of the techniques you might use for solving regular puzzles become significantly more complicated. For example, when considering x-wing and y-wing patterns, there are more rows, columns, and blocks to consider, and the candidate lists can be longer.
Other advanced techniques like Swordfish, Jellyfish, and chains can also be adapted to 16x16 Sudoku, but they need even more careful observation and logical deduction.
“One of the best challenges”
Puzzle enthusiasts love larger Sudoku’s because of this added challenge. George, an 81-year-old puzzle enthusiast had this to say:
“I’ve been solving puzzles for as long as I can remember, and 16x16 Sudoku is one of the best challenges I’ve come across. It keeps my mind sharp and gives me a sense of accomplishment when I finally crack a tough one. It’s like a workout for my brain, and at my age, that’s priceless.”
Bigger puzzles means a bigger sense of achievement when you finish them. Stay-at-home mum Anne told me:
“Being a mum is rewarding but can be exhausting. Playing big Sudoku puzzles is my escape from the daily grind. It’s my sanctuary of calm and focus. I love that moment when everything clicks into place, and I feel a rush of satisfaction. It’s my ‘me time’ and a perfect mental break.”
For those who enjoy variety and an added layer of complexity, hybrid puzzles merge Sudoku with other popular logic games. Killer Sudoku is probably the most popular variation of all. This hybrid combines Sudoku with elements of Kakuro. In addition to the standard Sudoku rules, players must also fill in sub-regions with numbers that sum to specified values, adding a new dimension of arithmetic to the puzzle.
Sudoku-X is a variation that includes the standard Sudoku rules plus an extra rule where the diagonals must also contain unique numbers. It adds an additional layer of complexity and requires players to consider diagonal constraints.
Samurai Sudoku (also known as Gattai-5) consists of five overlapping 9x9 grids arranged in a cross pattern. Solving it requires attention to multiple interlocking grids, making it a multi-dimensional challenge.
Colour Sudoku uses colours to fill the cells. The rules remain the same, but the visual aspect of colours can make the puzzle feel entirely different and is particularly appealing to those who enjoy a vibrant challenge.
If you’ve never given 16x16 Sudoku a try, then you’re missing out. Fortunately we’ve got you covered. We’ve put together a sampler of 4 puzzles for you to download and print.
If that taster whets your appetite for more, be sure to check out our range of 16x16 Sudoku books. We have easy, hard, and very hard puzzles to choose from.