Learn
Everything about Shikaku.
Shikaku is a logic puzzle with one rule: divide the grid into rectangles, each holding exactly one number, equal to the cells it covers. No luck, no arithmetic, no guessing. These four pages are everything we know about it.
The rules · 5 min
How to play Shikaku
The one rule, the two deductions, and a real 5×5 board worked from empty to solved in seven placements. Start here.
Read →Solving · 8 min
Shikaku techniques
Forced singles and cell ownership in depth, what to do when neither fires, and five habits that make you faster.
Read →Comparison · 6 min
Shikaku vs Sudoku
Both are pure deduction with one solution and no guessing. What changes is whether you are placing symbols or discovering shapes.
Read →Difficulty · 6 min
What makes a Shikaku hard
Not the grid size, and not the rectangles. It is how many times the direct deductions run out. The full ladder, 7×7 to 12×12.
Read →Then play today’s.
Everyone in the world gets the same Shikaku each day. Free, no ads, no subscription.
Download on the App Store