New to Shikaku? Learn the three rules on a 7×7, then get used to asking one question of every number: what shapes could it be, and which of them still fit? This page puts the guides in that order, with six small warm-ups to check yourself before you move up a size.
Your path, in order
- Learn the rules. The Shikaku rules page solves the game’s first level step by step. The one idea to take away: every rectangle holds one number, equal to its area.
- Start with numbers that can only be lines, like 5 and 7, and numbers near edges and corners.
- Draw every rectangle that fits only one way, and look around it straight away.
- When nothing fits one way, look for overlap.
- Do the warm-ups below. Six small grids, each practising an idea from the guides.
- Learn the other techniques. How to solve Shikaku covers all three.
- When a puzzle goes wrong, read the six common mistakes. The big one is drawing a rectangle before it’s certain.
- Move up a size when you’re ready (see below).
Warm-up: six small puzzles
Each has exactly one solution, and each needs one more idea than the one before. Solve it, then open the answer.
1. One way each
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Every number here fits only one way. The 5 can only be a line, and up its column it would take in a 6, so it fills the bottom row. The 6 in row 4 fits only two rows by three columns, rows 3 and 4 on the right, and the 6 above it takes rows 1 and 2 on the right. The 6 in row 3 fills the three-by-two block on the left, leaving the 2 the top-left corner.
2. In the right order
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Every number fits one way, if you take them in order. Start in the bottom-left corner: the 2 there can only go up, then the 3 beside it can only go up its column, and the 4 above runs up the first column to the top. Each rectangle drawn leaves the next number only one shape, around the grid to the last 2.
3. Overlap
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Three numbers fit one way: the 6 on the left, then the 4 and the 2 in the bottom-left. After that, every number has a choice. Look at the 4 in row 1: all the rectangles it could be cover row 1, columns 2 to 4, so no other number can use those squares. Three more numbers have overlaps like it, and once they’re used, every remaining number fits one way.
4. One overlap opens it up
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Five numbers fit one way, starting with the 4 on the right edge. Then the 6 in row 2, column 2: every rectangle it could be covers the square to its right, which rules out one of the 8’s rectangles. Now the 8 in row 3 fits one way, and the rest follow.
5. Only one number can reach
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The first five numbers fit one way, and an overlap and one more follow. Then look at row 3, column 1: only the 4 in row 4, column 1 can reach it, so the 4’s rectangle must cover it, and that leaves it one shape: rows 3 to 6 of the first column. The same idea, a square only one number can reach, settles three more numbers.
6. All three together
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Nothing fits one way at the start, so begin with overlaps: the 6 at the top, the two 10s and a 4 each have squares that all their rectangles share. Then only the 8 in row 4, column 5 can reach row 2, column 6, which leaves the 8 one shape. From there, every number fits one way.
When to move up a size
You’re ready for Medium (10×10) when you can finish Easy levels without guessing, and you look for overlap as soon as nothing fits one way. Overlap is needed on 31 of the 50 Easy levels, 48 Medium and every Hard one; on Hard (12×12), every level also needs a square only one number can reach.