How to play Stars

Play Stars

Stars is a puzzle about space. Every row, column and region wants a star, but stars can't stand next to each other — and that one restriction is enough to make every placement certain.

The rules

The grid is divided into regions by heavy lines. There are as many regions as rows.
Place stars so that every row, every column and every region holds exactly one star — or exactly two on Hard.
Stars may never touch: not side by side, and not diagonally either.

The puzzle is also known as Star Battle, its name at puzzle championships. Every puzzle has exactly one solution, and you can always reach it by reasoning. Most of the work is finding where stars can't go; the stars themselves come last.

An easy 6×6 puzzle: six regions, one star each. From Easy puzzle #1 — play it

Solved. One star in each row, column and region, and no two touching.

Your first moves

Look for the smallest regions. A region of two or three cells leaves very little choice, and often its star can only go in one place.

The tinted region has only one cell left that isn't ruled out, so that's where its star goes. From Easy puzzle #1 — play it

Each star you place rules out a lot at once: the rest of its row, its column and its region, and every cell touching it.

The star at row 5, column 3 rules out every cell touching it, diagonals included — the red crosses. From Easy puzzle #2 — play it

Marking those cells as you go is the whole game in miniature. The strategy guide covers the reasoning that takes you further.

Playing on this site

Tap a cell once for a dot — your note that no star goes there — and again for a star. A third tap clears it.
Long-press (or right-click) goes the other way round: star first.
Drag across open cells to dot them all at once, or across dots to clear them.
Stars that touch, or a row, column or region with too many stars, are marked in red straight away. Check shows any star or dot that disagrees with the solution, but only when you ask.
Hint names the next deduction and outlines the cells it settles. One hint per puzzle is free; after that there's a one-minute wait between hints.

Keyboard

Arrow keys move; S places a star, X a dot, 0 clears; Space cycles.
Z undoes, Y redoes, H asks for a hint.

Sizes and the daily puzzle

Easy: 6×6, one star per row, column and region.
Medium: 8×8, one star each.
Hard: 10×10, two stars each.

Each day's first puzzle is the same for everyone, and they follow the week from Monday's gentlest to Saturday's toughest, with Sunday the next toughest. After it, Next puzzle gives you as many more as you like.