Sudoku is defined by Merriam-Webster as a 9-by-9 grid puzzle in which the grid is divided into 3-by-3 boxes. Every row, column and box must contain the numbers one through nine, no repeats.

Everybody can solve a hard Sudoku. Maybe not right now, maybe not without some practice, but trust me, it’s possible. By the end of this article, you’ll be equipped to tackle intense puzzles ...

Not since the Rubik's Cube of 1980 has a puzzle been this hot. From its mind-teasers have sprung clubs, competitions, computer-games and a cult-like following.