วิธีเล่น Cube / 3D Sudoku

Cube Sudoku (also called 3D Sudoku or Tridoku) consists of two 9×9 Sudoku grids that share a common 3×3 box at their overlapping corner. Both grids must independently satisfy all standard Sudoku rules, and the shared corner box must simultaneously satisfy both grids' box constraint.

The shared corner box is part of both grids. Any digit placed in that box counts toward the uniqueness constraint for both grids simultaneously. This means solving either grid's corner directly constrains the other grid's corner — the two grids communicate only through this shared zone.

Yes. Both grids use the digits 1–9, and both follow standard Sudoku rules independently. The shared box makes the two grids interdependent. A digit placed in the shared box cannot repeat in any row, column, or box of either grid.

It is roughly twice as much work as a single Sudoku, plus the added challenge of managing the shared corner. Easy Cube puzzles are accessible for experienced Sudoku players. Hard and expert puzzles require actively exploiting the cross-grid constraint, which adds genuine complexity beyond simply solving two independent grids.

Alternate between the two grids rather than solving one completely before the other. Whenever you make progress in the shared corner box, immediately check what that means for the other grid. The shared box is the key to unlocking both grids — maximise information flow through it.

Easy puzzles take 15–30 minutes. Medium puzzles run 30–50 minutes. Hard and expert puzzles can take 60–120 minutes. The scale (two full grids) is the primary driver of solve time.