Step 2 of 5

Read the badge

The badge is half the clue. Read it before you count anything.

The rule of thumb: A shape badge cuts a clue’s options down, and a numbered square has only one size.

Every clue carries a shape badge as well as (usually) a number. A square badge means the patch is as wide as it is tall: a 9 with a square badge can only be 3×3, one size exactly. A wide badge kills every tall shape and the reverse, and the corner brackets mean any rectangle at all. A prime number is a giveaway too: a 5 or a 7 can only ever be a single row or a single column.

These practice boards each hinge on one clue whose badge does the decisive cut: the solve opens with it, and with the badge covered up — treated as “any” — it would have two or more fits instead of one, and the whole board would no longer have a single answer. When a clue looks like it has options, check the badge before you check anything else.

Where to look: Square badges first (they have a single size), then wide and tall. Prime numbers are one straight line, whichever way the badge allows.

Worked example

A real position from a board built around Read the badge. Purple: what the reasoning rests on. Dashed: the patch in question. Green: what it proves.

The clue at row 5, column 5 (purple) reads “4, square”. The dashed patch is the only one that fits both its number and its badge.

Cover the badge — pretend it says “any” — and the same number has 3 fits. The badge did the cutting; this is the one it leaves.

Practice it ↓