Rectangles, one number each
Play Shikaku online in the browser
In Shikaku, you divide a grid into rectangles. Each rectangle contains one number that tells you how many cells it covers. Patches.cafe starts with this rule and expands it into a free, 1,000-level browser puzzle campaign.
How Shikaku works
Start with a grid containing numbered clues. Draw rectangles until every cell is covered. Each rectangle must contain exactly one clue, and its area must equal that number. A 4 can be a 2×2 square, a 1×4 strip, or a 4×1 strip. A 5 must be a 1×5 or 5×1 strip: those are the only rectangular arrangements of five cells.
Rectangles cannot overlap or contain a second clue, and no cell can be left uncovered. When several shapes fit one number, check how each choice affects the neighbouring clues. A shape that fits locally may leave cells that no other rectangle can cover. See the solving strategies for more examples, or the controls and clue guide to learn how this works in Patches.cafe.
Japanese publisher Nikoli printed the puzzle as 四角に切れ, usually written Shikaku in English and sometimes sold as Rectangles. Patches.cafe is not a Nikoli product. It is a browser game that starts from that covering rule.
What a finished board looks like
This 4×4 example has five clues: 4, 2, 4, 2, and 4. Their areas add up to all 16 cells. The top-left teal patch and the brown patch are 2×2 squares. The two amber patches are separate 1×2 strips, and the bottom teal patch is a 1×4 strip. Every patch is a rectangle with exactly one clue.
To draw a patch, press one cell, drag to the opposite corner, and release. The clue can be anywhere inside the rectangle; you do not have to start on it. On a phone, tap a clue marked 1 to place its single-cell patch.
Play Shikaku online here
Open the game menu, choose Campaign, and start at level 1 to learn the basic rectangle rule. The first 11 levels use ordinary numbered clues; additional mechanics can appear from level 12. Patches.cafe is a Shikaku-style game with its own rules later in the campaign, rather than a dedicated classic-only mode.
Boards are generated from a complete solution. A solver also checks for alternative solutions, and the generator retries when it cannot confirm a unique result. That extra check is separate from simply building a board that can be solved.
No account is required, and your progress is saved in your browser. For offline play, install the game while connected and let the offline download finish. You can then continue the campaign without an internet connection. Rankings and optional progress synchronization need internet access.
What happens after plain Shikaku
Later levels introduce additional rules. Gold clues require squares. Horizontal arrows require patches wider than they are tall; vertical arrows require taller patches. Coffee stains hide clues until a neighbouring patch is placed. Matching letters link patches of the same shape. Marked double-layer cells must be covered twice. These are Patches.cafe variations, not standard Shikaku rules.
You can learn each symbol as it appears. Espresso Blitz adds a time limit, while Perfectionist limits your moves. Daily Brew offers a shared puzzle for each UTC date. In the level editor, you draw a solution and generate clues and a code to share it.
Read about Patches.cafe for the story behind the game and more about the campaign.
Open a Shikaku-style board
Choose Campaign and level 1 for the basic rules. You can move to a later starting point when you want additional mechanics.
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