If there is any Sudoku type which is very similar to Classic Sudoku, then it is Diagonal Sudoku. If someone knows about Classic Sudoku Rules, then it is very easy to describe the additional rules of numbers 1 to 9 coming uniquely on two main diagonals. However solving a Diagonal Sudoku sometimes becomes very tricky. Diagonal Sudoku is known with different names e.g. X Sudoku, Extreme Sudoku or Sudoku X. However I will using Standard name Diagonal Sudoku for these type of puzzles. Recently I have created few Diagonal Sudoku puzzles and this page I am creating to give reference to these puzzles.
Rules of 9x9 Diagonal Sudoku
Place a digit from 1 to 9 into each of the empty squares so that each digit appears exactly once in each of the rows, columns, outlined 3x3 box, and two main marked diagonals.
Following is the link to the 9x9 Diagonal Sudoku puzzles
Rules of 6x6 Diagonal Sudoku
Place a digit from 1 to 6 into each of the empty squares so that each digit appears exactly once in each of the rows, columns, outlined 2x3 box, and two main marked diagonals.
Following is the link to the 6x6 Diagonal Sudoku puzzles
Diagonal Sudoku Variations
Following is links to the Diagonal Sudoku variations. Rules of these puzzles are explained in the respective links
Rules of Diagonal Arrow Sudoku
Arrow Sudoku Rules apply. Additionally each marked diagonal must also unique numbers i.e. numbers from 1-9 only once.