Star Battle Solver

Star Battle Solver: rules, how to use it, tips

Place stars so every row, column and region holds the same number, and no two stars touch — not even diagonally.

The rules

The grid is divided into as many regions as it has rows.
Place stars so that every row, every column and every region contains exactly the same number of stars — 1, 2 or 3, as stated.
No two stars may touch, not even at a corner.
There is exactly one solution, and it can be found by reasoning.

Using the solver

Choose the stars per line and the grid size, then paint each region: pick a colour swatch and drag over its squares (or press Sample).
Press Solve and step through: full lines, only-room, too-close, squeezes and every-way checks, each explained with the squares highlighted.

Tips

Mark around every star. As soon as you place a star, cross out its eight neighbours and the rest of any row, column or region that now has all its stars.
Small regions first. A region of two or three squares has very few places for its star — and every one of them may touch the same square outside it, which can then be crossed out.
Squeezes. If every free square of a region lies in one row, that row’s star belongs to the region: cross out the rest of the row. The same works with two regions inside two rows, three in three.
Too close. Imagine a star in a square. If its neighbours would cover every free square of some region, row or column, that square cannot hold a star.

The full guide, with a worked example and common mistakes: How to play Star Battle.

Questions

Is Star Battle the same as the daily queens-style puzzles?

The 1-star version is: one per row, column and colour region, and none touching. Star Battle also comes in 2-star and 3-star versions on bigger grids, which you can play here.

Can two stars touch diagonally?

No. Stars may not touch at all — not side by side and not at a corner.

How do I enter a puzzle from a book or app?

Open the Star Battle Solver, choose the size and stars per line, paint the regions and press Solve to step through every deduction.

What do the dots mean?

With ‘Show squares ruled out by my stars’ on, dots mark squares that cannot hold a star because they touch one of your stars or sit in a line or region that already has all its stars.

Star Battle Solver — Step by Step