The enormous popularity of sudoku across the world is due to a couple of simple facts: Sudoku rules are easy to learn; Sudoku is not a math game, but is rather about identifying logical patterns…

The goal of sudoku is simple: fill in the numbers 1-9 exactly once in every row, column, and 3x3 region. Notice that every row, column and 3x3 region contain every number from 1-9 exactly once.

**Notes:** It is typical to use notes (also called mark-ups) to plot in possible numbers. The image below shows these notes, indicated by the small numbers. For example, look at the very last cell (the lower, right). The player
has determined that only the numbers 1, 4, 5 or 8 can be placed in that cell, and has thus put these numbers in as temporary notes.

Sudoku puzzles vary in difficulty from simple to devious. Scare yourself into some puzzle game fun with Sudoku!