Cross Sudoku - Rules & Guide

Tip 1: Prioritize bombing of the "triple core area"

The four corners of the central board (the four corners of the blue line frame in the picture) are the "super hub" of the entire game. The numbers filled in these four palace grids will be subject to strict scrutiny on the three disks at the same time. Because the repulsive force is the greatest and the number that can survive is the least, this is often the point where clues converge most intensively and it is easiest to use the elimination method to force out the only candidate number.

Technique 2: Derivation of the "cross" on the center disk

Out of the 9 squares in the central disk, 8 are shared by the peripheral disks, but the most central square is completely independent. When you unlock the numbers on the surrounding outer disks, the numbers will cut straight into the center disk like a cross lightsaber. Using the four "wings" on the periphery to cover the center with crossfire can quickly force the center to surrender.

Tip 3: Cut off independent market thinking

In Cross Sudoku, adjacent peripheral boards (such as above and left) create direct physical overlap through the central corners, a feature not found in most other variations (such as Samurai Sudoku). When you get stuck solving a puzzle on the upper board, you can go directly to the left or right board to look for clues. Because they are "directly adjacent" conjoined twins, they must not be treated as isolated Sudokus.

Example image: The blue wireframe is the central disk, observe the "triple overlap" at its four corners

A: The blue border is just to visually help you clearly mark the 9x9 Sudoku board in the center. It does not have any additional rules. You simply need to make sure that every row, column, and palace in the blue box meets the basic Sudoku rules of 1-9 without repetition.

A: The difference is huge! In Samurai Sudoku, the central disk overlaps the four peripheral disks "diagonally" without any contact between the peripheral disks. The cross Sudoku is "welded" overlapping up, down, left and right. This results in the fact that the four squares in the central corners of the Cross Sudoku are "shared by three disks", and there is also a direct overlap between adjacent peripheral disks (such as the top and left), making the involvement even closer and more complicated.