Each puzzle consists of a 9x9 grid containing numbers in various squares. Your task is to fill all the blank squares so that the numbers 1 to 9 appear once in each row, column and irregular shaped box.
You have 80,000 puzzles presented in two forms and four levels.
• Forms: Symmetrical or asymmetrical.
• Levels: Beginner, confirmed, expert and extreme.
Each of our puzzles has only one solution.
In the three first levels all puzzles are solved through a series of logical deductions. It is not at all necessary to use groundless hypothesis or multiple choices to find any solution.
The fourth level, so called "Extreme" needs "multiple choices" to be solved.
See below: Levels of grids to play online
Choice of puzzles: Our irregular sudoku were designed and graded so that at the same level the higher the puzzle number, the more difficult the solution, with this nuance that in our classification, at equal levels and numbers, symmetrical puzzles are a little easier to solve than asymmetrical ones. Indeed, the symmetrical ones have an additional constraint - precisely to be symmetrical - so they have fewer empty squares to solve. Also note that the aspect of difficulty is subjective, because different solving techniques suit different people.
Why play irregular sudoku? Irregular sudoku is a variation of sudoku. It allows veterans of sudoku to find new visual configurations. The beginner and confirmed levels are solvable by logical deduction. Only the expert level requires you to pencil in the candidates if you cannot see the solution.
• Puzzles "Beginner" are fully resolvable by "Inclusion" while accepting other methods.
• Puzzles "Confirmed" are fully resolvable by "Inclusion" and "Exclusion" while admitting to other methods.
• Puzzles "Expert" are solvable by "Inclusion", "Exclusion" and "Pairs exclusive".
• Puzzles "Extreme" are solvable by "Inclusion", "Exclusion", Pairs exclusive" and "Multiple choices"
Number of multiple choices in extreme symmetrical puzzles:
– From No. 1 to No. 3000: a single multiple choice.
– From No. 3001 to No. 6000: two multiple choices.
– From No. 6001 to No. 9000: three multiple choices.
– From No. 9001 to No. 10000: four multiple choices.
Number of multiple choices in extreme asymmetrical puzzles:
From 1 to 19 multiple choices are possible, in proportion with the puzzle number.
Extreme asymmetrical puzzles with the highest numbers are the most difficult to be solved and just proposed as a "curiosity".
For more details on these techniques similar to those of regular sudoku, see: General help.
An irregular jigsaw puzzle is symmetrical when the squares that compose it are arranged equally around the central square known as the center of symmetry. This is only esthetic and does not change the resolution mode of the grid. Indeed it is the puzzle that is symmetrical and not the solution. However, the advantage of non-symmetrical puzzles is that, having one less constraint, they allow the elaboration of more difficult problems.
Our irregular jigsaw sudoku are printable through the menu 9X9 JIGSAW SUDOKU and the link Print grids.
You can select prints in white, gray, hatched or colored.
Our irregular jigsaw sudoku are downloadable through the menu 9X9 JIGSAW SUDOKU and the link Download pdf puzzles.
You can select pdf files in white, gray, hatched or colored.
All irregular jigsaw puzzles offered on this site are created by sudoku-puzzles-online.com and these puzzles can be reproduced free on condition that a link to the web site sudoku-puzzles-online.com appears on every reproduced page.