Sudoku April 1st puzzleWow, it is a long time since I posted here. So much to do, so little time!

I guess that means I might as well keep it brief now, then. On that basis:

Here’s a puzzle for April 1st. It’s actually a normal puzzle without tricks – it just spells ‘FOOL’ in the given numbers. Like any Sudoku, simply place 1 to 9 in each row, column and bold-lined box.

Sudoku Box-Jigsaw 9×9 1 puzzle

The puzzle combines regular Sudoku with Jigsaw Sudoku. Just place 1 to 9 once each into all of the nine rows, columns, 3×3 boxes (indicated by both shaded and unshaded background areas) and bold-lined jigsaw regions.

If you’re not sure of the rules, or haven’t seen one of these puzzles before, then check out the example puzzle I posted last week.

Jumbo 3D sudoku puzzle

There’ve been 3D sudoku around for a while, and in terms of solving there’s little difference from regular sudoku except for the increase in size and the way in which the bendy regions can easily cause you to miss an “obvious” deduction! This is the biggest I’ve seen, but it’s perfectly possible there are larger ones I’m not aware of.

Anyway, if you’re a fan of samurai sudoku or any other kind of large sudoku then you should enjoy this, I hope!

Average solving time is around 1 hour.

Sudoku Xtra 24 is now finally available! It’s packed with 130 puzzles of a wide range of types, including a huge variety of sudoku variants.

This issue I’ve included some new sudoku types such as Two-grid Interconnected Sudoku, Mystery Multiple Sudoku and Blackout Sudoku. I’ve also made an effort to include all of the most popular variants as requested by readers, such as Consecutive Sudoku, Inequality Sudoku, Odd/Even Sudoku – and of course many more.

There’s also a range of non-sudoku puzzles, including Light-up/Akari, Hashi, Slitherlink, Battleships, Skyscrapers, Calcudoku, Futoshiki, No Four in a Row, and more!

It’s available either as a PDF to print yourself (every page is self-contained, so you can print only the pages you want), or as a professionally-printed book direct from Amazon – there are links for all of these on the Sudoku Xtra site.

Sudoku Christmas Star puzzle

Just that. (Place 1-9 once each into every row, column and bold-lined 3×3 box).

I’ve recently launched a new series of ‘101 Giant Sudoku’ books, to cater for those who like their Sudoku to be considerably larger than normal!

You can see the entire series at PuzzleBooks.org (scroll to the bottom) or visit Amazon and search for “101 giant sudoku”.

There are currently 12 books in the series: 14×14, 15×15, 16×16, 18×18, 20×20, 21×21, 22×22, 24×24, 25×25, 28×28, 30×30 and 36×36.

The larger puzzles work just as you’d expected, so in Sudoku 36×36, for example, you must place 0-9 and A-Z into every one of the 36 rows, 36 columns and 36 6×6 boxes!

These puzzles are designed so they don’t need any advanced logic – just scan the rows and columns and boxes to see what’s missing and what can fit where.

All of the puzzles are designed with attractive 8-way symmetry patterns.

It’s pretty darn awesome, even if I do say so myself!  It handles the screen touch events directly so it’s just as fast as running a native application on the iPad or iPhone. It also works on other devices.

Little-Killer Sudoku 9×9 1 puzzle

I’ve also seen Little Killer puzzles which have an additional restriction that no number can repeat on either of the two main diagonals, but I haven’t used that rule here, so numbers can repeat. Apart from the addition of the Little Killer clues, this is a regular Sudoku puzzle.

Zero Killer Sudoku 9×9 1 puzzle

Usual Killer Sudoku rules apply: Place 1 to 9 in each row, column and bold-lined box as usual, but you must also ensure that each dashed-line cage adds up to the total given at the top-left of it. Numbers can not repeat in a dashed-line cage.

Speaking for myself, I found this puzzle really challenging to solve, but I can promise you that there’s no need to guess or use trial and error in any way – every deduction can be made using standard killer solving techniques.

Good luck!

Sudoku Snake 9×9 1 puzzle

Each of the shaded snakes consists of only ‘consecutive’ cells along its length, which means that any two cells joined by a snake must have values with a difference of 1, such as 2&3 or 7&8.  So for example the 4-square-long snake at the top-left might have 2323 along its length, or any valid fit such as that.

In addition follow usual sudoku rules. Also note that only the cells joined by the snakes have any special relationship – any other pair of cells may or may not be consecutive (unlike in regular consecutive sudoku).

Sudoku Trio Odd/Even 9×9 1 puzzle

Simply place 1-9 once each into every row, column and bold-lined region, as in a regular sudoku, but in this Odd/Even puzzle all of the even digits are in shaded cells. This is also a Trio sudoku too so each of the cells with an inset square contains 4, 5 or 6 and each of the cells with an inset circle contains 7, 8 or 9. Those without an inset square or circle contain 1, 2 or 3.

Using these rules you need only 3 givens for a valid unique puzzle. That’s the minimum number as you can probably easily convince yourself, because, despite its perhaps intimidating appearance, it’s essentially a set of trivial 1- and 2-digit sudokus laid on top of each other.

Blackout Jigsaw Sudoku 9×9 puzzle

The rules are simple: in each row, column and bold-lined jigsaw region you must place 8 different digits in the range 1 to 9.  Don’t place a digit on the shaded squares.

If you prefer you can consider it as a standard jigsaw sudoku where the black cell can represent any value, and the value can be different for the row, the column and the jigsaw region.  For example the shaded square on the top row could take the place of a 7 in that row, an 8 in its column and a 2 in that jigsaw region.

Good luck!

Sudoku Anti-King Argyle 9×9 1 puzzle

Anti-king means that no number repeats a “king’s move away in chess”. In practice this means that no two identical numbers touch in any direction, including diagonally.

Argyle means that no number repeats on any marked diagonal. The diagonals form an ‘Argyle’ Scots tartan pattern.

And since it’s a Sudoku, you must also place 1 to 9 in each row, column and bold-lined 3×3 box.

Good luck!

Frame Sudoku 9×9 1 puzzle

Regular Sudoku rules also apply – place 1 to 9 once each in all rows, columns and bold-lined boxes.

The actual logic in this is not especially tricky, but I certainly found it took me quite a while to test solve it (20 minutes or so, although I was watching TV…) – I’d be interested to know how long it takes you to solve it too!

Sudoku Diagonal 9×9 1 puzzle

You can now also keep track of this and future puzzles I publish using The Griddle’s puzzle tracking system. The following buttons update the status of the puzzle:

Non-consecutive Sudoku puzzle

I thought I’d start off with Non-Consecutive Sudoku.  This is a minor variant on Consecutive Sudoku, where all the rules of standard Sudoku apply but there is one additional constraint:

• Neighbouring squares are not consecutive.  This means there is never a difference of ‘1′ between two edge-adjacent squares (i.e. touching, not including diagonally).

For example, if a square contains ‘3′ then any neighbouring square cannot contain either ‘2′ or ‘4′.

Good luck!