Through the years, Sudoku has become so popular a game that many variants have sprung from its original 9x9 grid puzzle. From the classic 9x9 grid puzzle, the 16x16 Sudoku puzzle was inspired. This made playing Sudoku more challenging for those who take time to complete it. Although both the 16x16 and 9x9 Sudoku puzzles have game rules that are quite identical to each other, we can still find little differences between them. Let us take a closer look at the ways on how to play this particular Sudoku puzzle variant and how it differs from the classic 9x9 grid Sudoku puzzle.In terms of rules, there is not much difference between the classic 9x9 Sudoku puzzle and the 16x16 grid puzzle. You still have to see to it that no number should appear more than once on every row, column, and sub-square. Thus, in a 16x16 puzzle, the numbers 1 to 16 should be written and placed only once on each of those said places.