Sudoku

From Puzzlewiki

Sudoku involves filling any grid or array-like shape with a set of symbols (typically numbers) one per row, column, and predefined area. Most Sudoku are 9x9 in size, with 3x3 boxes, although larger and more unusual shapes are possible.

Sudoku originated as Number Place in Dell Variety Puzzles. Number Place required solvers to place the numbers 1 through 9 in each row, column, 3x3 square, and major diagonal. Occasionally a 16x16, using the numbers 1 through 16, would appear in Challenger sections.