Patches — the Rectangle-Division Puzzle
Patches is a rectangle-division logic puzzle: cut the whole grid into rectangular “patches” so that each one holds exactly one number, and that number is the number of cells in the patch. The mechanic is the classic Japanese puzzle shikaku, so the board below is the real thing — drag to draw a patch, tap one to erase it. Every board has exactly one solution reachable by logic alone, and New deals another whenever you want one.
Play Shikaku — more sizes & the daily board →
How to play Patches
- Look at a number — it tells you how many cells its patch must cover. A 6 needs a rectangle of six cells: 1×6, 6×1, 2×3 or 3×2.
- Drag across the grid to draw that rectangle. Tap a finished patch to remove it if you change your mind.
- Give every patch exactly one number — a rectangle with two numbers in it, or none at all, is always wrong.
- Start with the numbers that have only one possible shape — a 1 is its own cell, a prime like 7 can only be a 1×7 strip, and numbers wedged into a corner have few ways to fit.
- Cover the whole grid. When every cell belongs to exactly one patch and every patch matches its number, the board is solved.
What is the Patches puzzle?
Patches asks you to partition a grid into rectangles, one per number, with each rectangle’s area equal to its number. There is no arithmetic beyond multiplying sides, no guessing and no hidden information — every board is decided from the start and can be reasoned out cell by cell.
The puzzle type is far older than any one app: it has been published in Japan for decades as shikaku (四角に切れ, “divide into squares”), and also appears as “rectangles” or “divide by box”. If you have played it under any of those names, this is the same game.
How to solve it: three reliable openings
Constrained numbers first. A 1 is always its own single cell — fill every 1 immediately. Primes are next: a 5 or a 7 can only be a straight strip, so its orientation is often forced by the grid edge.
Then corners and edges. A number near a corner has far fewer legal rectangles than the same number in open space, so the board tends to resolve from the outside in.
Finally, orphan cells. If a cell can only ever be reached by one number’s rectangle, that rectangle must stretch to cover it. Hunting for cells that nothing else can claim is the technique that cracks the harder boards.
Patches, shikaku, and where to play more
Patches and shikaku are the same puzzle under two names, so everything on this site works for both. The main shikaku page has 5×5 and 7×7 boards with the full rules, and the shikaku of the day deals one shared board a day if you would rather build a habit than binge.
If you like partition-and-deduce puzzles, Nurikabe asks you to build islands around numbers instead of rectangles, and Nonogram turns row and column counts into a picture.
Patches: FAQ
What are the rules of Patches?
Divide the whole grid into rectangles. Each rectangle must contain exactly one number, and that number must equal the rectangle’s area in cells. Every cell ends up in exactly one rectangle.
Is Patches the same as shikaku?
Yes — it is the same rectangle-division mechanic that has been published in Japan for decades as shikaku (also written “rectangles” or “divide by box”). The boards here run on the same engine.
Can a patch contain two numbers?
No. Exactly one number per rectangle — a patch with two numbers, or with none, means something earlier went wrong.
Where do I start on a hard board?
Fill every 1 first, then the primes (5, 7, 11), whose rectangles can only be straight strips. After that, look for cells that only one number could possibly reach.
How many puzzles can I play?
As many as you like — tap New for a brand-new board any time, free, with no download and no sign-up.