How to play Star Battle: the rules, grid sizes and your first solve

Updated 2026-10-30

Star Battle is a logic puzzle where you place stars in a grid so that every row, every column and every outlined region holds the same number of stars, and no two stars ever touch. The rules fit in one sentence, yet the puzzles range from a two-minute warm-up to a proper workout.

The Star Battle rules

A Star Battle puzzle is a square grid of n×n cells. Thick lines divide it into exactly n regions of different shapes. Each puzzle also tells you a number k: how many stars belong in every row, column and region. Your job is to place the stars so that all of these rules hold at once:

1. Rows: every row contains exactly k stars.
2. Columns: every column contains exactly k stars.
3. Regions: every outlined region contains exactly k stars.
4. No touching: two stars may never sit in neighbouring cells, and that includes diagonal neighbours. Each star is surrounded by a ring of up to eight empty cells.

A well-made puzzle has exactly one solution, and you can always reach it by reasoning alone. You never need to guess. If you find yourself stuck, there is a logical step you have not spotted yet, which is a big part of the fun.

Common grid sizes

Star Battle grids come in a few standard sizes, and the star count grows with the grid:

• 5×5 to 8×8 with 1 star: the friendliest format. One star per row, column and region. A 5×5 grid is a good place to learn, and 8×8 already asks for some real thinking.
• 10×10 with 2 stars: the classic competition size. Two stars per row, column and region, which means 20 stars in total and far more interaction between regions.

Larger grids with more stars exist, but these sizes cover most of what you will meet. If you have played the daily Queens puzzle, you already know the 1-star format: it is the same set of rules with queens instead of stars.

How to use X marks

Most of the work in Star Battle is not placing stars but ruling cells out. That is what the X mark is for. Whenever you can prove that a cell cannot hold a star, mark it with an X. Good players place many more Xs than stars.

Some typical reasons to place an X:

• The cell touches a star you have already placed, horizontally, vertically or diagonally.
• The cell's row, column or region already has all its stars.
• Putting a star there would leave some other region with no legal cell at all.

As Xs pile up, regions shrink to a handful of open cells, and stars start to place themselves. When a region, row or column has exactly as many open cells left as stars still needed, every one of those cells must be a star.

Walking through the opening moves

Here is how the first minute of a typical 1-star puzzle might go, described in words.

1. Look for the smallest region. Say one region is just two cells side by side in the top row. Its star must be in one of those two cells, so you already know the top row's star is inside that region. Every other cell in the top row gets an X.

2. Look for cells that see every option. The two cells of that small region are neighbours, so the cells directly below them touch at least one of them. Any cell that touches both possible star positions is ruled out whichever one turns out to be the star. Mark those with X.

3. Look for regions stuck in one line. Perhaps another region lies entirely within the second column. Its star must be in that column, so every cell of the second column outside that region gets an X.

4. Find a forced star. After those Xs, maybe a region in the corner is down to a single open cell. That is a star. Place it, then X its eight neighbours, the rest of its row and the rest of its column.

5. Repeat. Each new star removes a row, a column and a region from play and creates fresh Xs. Scan again for small regions, lines with one open cell, and regions confined to a single row or column. Puzzles usually snowball from here.

These moves are the backbone of every solve. Once they feel natural, our guide to Star Battle strategy and solving techniques covers counting arguments and the 2×2 rule for harder grids.

Tips for your first few puzzles

• Always mark the full ring around a new star straight away. Forgotten neighbours are the most common source of mistakes.
• When stuck, scan region by region and ask: "Where could this region's star possibly go?"

Ready to try it? Play Star Battle for free in your browser, starting with a small grid. If you are coming from number puzzles, you may also enjoy our comparison of Star Battle and Sudoku.