The shared core: cut the grid into rectangles
Patches and Shikaku ask for exactly the same finished picture. You get a square grid with a scattering of clue cells, and you have to partition the whole thing into rectangles so that every rectangle contains exactly one clue, every clue belongs to exactly one rectangle, and every cell ends up covered — no overlaps, no leftovers. Both are pure deduction puzzles: a well-formed board in either game has exactly one solution, and you never have to guess to find it.
That shared skeleton is why the two games feel identical for the first thirty seconds. Everything that separates them lives in one place: what a clue is allowed to say.
The real difference: area clues vs. shape clues
In Shikaku, a clue is a number, and the number is an area. A 6 means “the rectangle I sit in covers exactly six cells,” and any rectangle of area six qualifies — 6 × 1, 3 × 2, 2 × 3 or 1 × 6. Working out which of those factor pairs actually fits, given the walls and the neighbouring clues, is the whole game.
In Patches a clue carries up to two pieces of information: a shape family and, usually, a size. The families are Square (width equals height), Wide (strictly wider than tall), Tall (strictly taller than wide) and Freeform (any rectangle at all). So a Wide 6 clue throws out half the candidates before you have even looked at the board, while a Freeform clue with no number tells you only that some rectangle lives there.
Shikaku
Clue: 6
An area number on its own. All four rectangles of area 6 are legal, and the board around the clue decides which one you can actually fit.
Patches
Clue: Wide · 6
Shape plus size. Half the candidates are gone before you look at the board, because a Wide patch must be strictly wider than it is tall.
The consequence runs deeper than it first looks. A Shikaku clue is always complete — it pins the area exactly, every time. A Patches clue can be deliberately partial in either direction, and reconstructing the missing half from the geometry around it is the skill the game is actually testing.
Where each puzzle came from
Shikaku is much the older of the two. It is a Japanese pencil puzzle published by Nikoli — the house that popularised Sudoku — since 1989, under the name 四角に切れ (shikaku ni kire, roughly “cut into rectangles”). It turns up in English as Rectangles, Divide by Box and Sikaku, but those are the same puzzle under different publishers' names, not variants. Its rules have been stable for decades and there is a deep back catalogue of hand-made boards, which is part of the appeal: it is a mature, settled format.
Patches is the newcomer. It is LinkedIn's spatial logic game, built on the Shikaku skeleton with a shape constraint layered on top — an idea closer to the Tatamibari family, where a clue symbol governs a rectangle's proportions rather than its area. Blending the two is what makes Patches its own puzzle rather than a Shikaku reskin, and it is why a Patches board can stay interesting at 6 × 6 where a Shikaku that small would fall apart in seconds.
Board size and session length
Shikaku is usually played big. Ten by ten is a common starting size and published boards go well beyond it, because the puzzle needs open space for the factor-pair ambiguity to bite. A large Shikaku is a sit-down puzzle.
Patches runs smaller and faster. This site's daily board is a 6 × 6, and you can pick 6 × 6, 8 × 8 or 10 × 10 in Unlimited Mode. A 6 × 6 Patches board is a coffee-break puzzle: most signed-in players here finish one in under half a minute once the shape rules are second nature.
What makes each one hard
In Shikaku the difficulty lever is ambiguity. Large numbers have many factor pairs, clues far from a wall can extend in four directions, and a big open region can be carved several plausible ways until a distant constraint rules the wrong ones out. Shikaku gets harder mostly by getting bigger and emptier.
In Patches the lever is withheld information. Easy boards state both shape and size on every clue. Medium hides the number on about half of them. Hard turns most clues Freeform and drops many numbers, so you are routinely deducing a clue's own size from what its neighbours cannot possibly cover. Patches gets harder by telling you less, not by getting bigger — the full breakdown is in how to play Patches.
Techniques that transfer
If you already solve one of these, most of your instincts carry straight over:
- Start with the most constrained clue. In Shikaku that is a prime area — a 7 can only be 7 × 1 or 1 × 7. In Patches it is a Square with a number: a Square 9 is a 3 × 3 and nothing else.
- Work the edges and corners inward. A rectangle cannot run off the board, so clues near a wall have far fewer legal placements. Corners are often the first cells you can resolve in either game.
- Solve by coverage, not by clue. Pick an empty cell and ask which clues could ever reach it. If only one can, that clue's rectangle is forced to include it. This is the strongest single technique in both puzzles.
- Use clues as walls. No rectangle may contain two clues, so every other clue on the board is a barrier your current rectangle cannot cross.
One habit does not transfer. In Shikaku, listing the factor pairs of the number is always your opening move. In Patches you will often have a shape and no number at all, and the equivalent opening move is asking which orientations the surrounding empty space still permits — geometry first, arithmetic second.
At a glance
| Patches | Shikaku | |
|---|---|---|
| What a clue says | A shape family (Square, Wide, Tall, Freeform) and, often, a cell count | A number, always — the exact area of its rectangle |
| Can a clue be incomplete? | Yes — a shape without a number, or a Freeform clue with or without one | No — every clue is a full area constraint |
| Typical board | 6 × 6 daily here; 6 × 6, 8 × 8 and 10 × 10 in Unlimited Mode | 10 × 10 and up; published boards run much larger |
| Where difficulty comes from | Withheld information — hidden shapes and hidden sizes | Open space and numbers with many factor pairs |
| Typical solve | Under half a minute on a 6 × 6 for most signed-in players here | Grows with the grid; large published boards are sit-down puzzles |
| Origin | LinkedIn's games slate — a Shikaku descendant with shape clues | A Japanese pencil puzzle published by Nikoli |
So which one should you play?
Play Shikaku if you like arithmetic-flavoured deduction, bigger boards and a longer sit — and if you want the original that everything else in this family descends from. We run a free Shikaku site of our own at Shikaku Puzzles, so you can try the classic form without leaving the family of games we build.
Play Patches if you want a shorter board, a second axis of reasoning to chew on, or you are practising for LinkedIn's daily puzzle. Shape clues make the early moves quicker and the endgame trickier, which suits a small grid.
In practice they reinforce each other. Shikaku sharpens your sense of how a number constrains a region; Patches sharpens your sense of how a shape does. Learn one and the other stops being a new puzzle and starts being a variant — which is exactly what it is.
Ready to try a board?
Start with today's Patches Game if you want the shared daily board, or open Patches Game Unlimited to pick your own size and difficulty. If the shape rules are new to you, read how to play Patches first — it covers every clue type with a worked example.