Each number belongs once in every line, along every dimension.
In 2D, solve the rows and columns on a single board. There are no Sudoku boxes.
In 3D, those rules extend through a stack of boards. Move the Layer slider to compare cells at the same row and column.
In 4D, a World contains a stack of layers. Change worlds to follow another direction through the puzzle.
In 5D, a third slider connects sets of worlds. All five directions follow the same rule.
Select an empty cell and enter a number. Use Pencil to add your own notes. The game doesn't add notes or flag mistakes automatically.
You can request a hint or check under More. Your puzzles save separately in this browser. Undo and Redo survive reloads for the most recent 2,000 edits in each attempt.