Diagonal Center Dot Frame Sudoku Rules
Frame Sudoku (Outside Sum Sudoku) . Numbers in the outside frame equal the sum of the first three numbers in the corresponding row or column in the given direction.
Additional Rules:
Diagonal Sudoku Rule: Sudoku main diagonals also contain the digits 1 through 9.
Center Dot is a variant of sudoku, where central cells of each region form an extra region. This region must contain digits 1 through 9.
Frame Sudoku (Outside Sum Sudoku) . Numbers in the outside frame equal the sum of the first three numbers in the corresponding row or column in the given direction.