Contact puzzlemix
Play free puzzles         Create free account         Instructions         Discussion forum         Log in    

Brained Up, daily online brain training site
daily online brain training
Cutting-edge brain training created by Dr Gareth Moore
Think faster, better,
and improve your mental capabilities

Sudoku Xtra, written by Dr Gareth Moore
Sudoku Xtra 24
logic puzzle compendium
Printed puzzles from Dr Gareth Moore

Killer Sudoku

Jigsaw Sudoku
Consecutive Sudoku
Kropki Sudoku
Sudoku XV
Oddpair Sudoku
Toroidal Sudoku
Killer Sudoku-X
Killer Sudoku

Jigsaw Killer

Looking for puzzles for your book, magazine or newspaper?

How to play Odd Pair Sudoku

An Odd Pair Sudoku puzzle adds one extra constraint to the standard Sudoku grid - not only must you place 1 to 9 (or 1 to whatever the width of the puzzle is) in each row, column and bold-lined box, but you must also follow the orange 'Odd Pair' markers:

  • Orange 'o's between squares (or boxes when viewed in very old browsers) indicate that the sum of the two numbers in those squares is odd. So for example 3 and 6 are an 'odd pair' (since 3+6=9, which is odd), as are 1 and 2 (1+2=3, which is odd).
Unlike in Consecutive Sudoku there is no inverse rule, so the absence of a marker means nothing.

In the example puzzle shown here you can immediately narrow down the candidates next to some of the odd pair markers by comparing them with the pre-given numbers, as shown in the picture below. Small 'pencilmark' digits have been added to show valid values in these squares - pencilmarks are useful for helping keep track of possible solutions as you work through the puzzle.

It's worth noting that, because the numbers in each odd pair sum to an odd number, it must always be the case that one number is odd and the other is even.

When this puzzle is fully-solved you will have 1 to 9 in each row, column and 3-by-3 box, and all digits with orange 'o's between them will sum to an odd number, as shown here:

Note again that there is no inverse rule, so numbers without an orange 'o' can also form odd pairs.

And that's all there is to Odd Pair Sudoku.

Back to puzzle rules choice page

©Brained Up Ltd/Gareth Moore 2005-2018 - email - publishers please visit Any Puzzle Media - our privacy policy - registered in England & Wales no. 8642393