Sudoku and Shikaku are both grid-based logic puzzles you solve by pure deduction, so solvers naturally wonder how alike they really are. The short answer: Shikaku is distant to Sudoku. Below we lay out what the two share, where they part ways, and whether the skills you have built on Sudoku will carry over.
- Grid: Rectangular
- Closeness to Sudoku: Distant
- Also called: Divide by Squares, Rectangles
What is Shikaku?
Cut the grid into rectangles so that each contains exactly one number, equal to that rectangle's area. Here are the rules in full:
- Partition the whole grid into rectangles.
- Each rectangle holds exactly one number, and its area equals that number.
- Rectangles never overlap and cover every cell.
See a Shikaku grid
Shikaku cuts the grid into rectangles, each containing exactly one number equal to its area. Below, a "4" rectangle (2×2) sits beside a "2" rectangle (1×2).
A 2×2 rectangle holds the number 4 (its area); a 1×2 rectangle holds 2.
Both are single-solution logic puzzles solved by elimination, and both reward spotting where only one arrangement fits a clue. But you draw rectangles sized by their number rather than placing digits, and there is no row, column or box rule — a distant relative.
What Shikaku shares with Sudoku
- Both are single-solution logic puzzles solved by elimination, not guessing.
- Both reward spotting where only one arrangement can fit a clue.
How Shikaku differs from Sudoku
- You draw rectangles sized by their number, rather than placing digits.
- There is no row, column or box rule at all.
Do Sudoku skills transfer?
No technique transfers directly, but the "which shapes can this clue possibly take, and which are ruled out?" reasoning is close kin to Sudoku candidate elimination.
The verdict
Shikaku is a grid-division puzzle that shares Sudoku's elimination logic but not its number placement.