Star Battle rules
Star Battle takes a minute to learn: put stars into the grid so that every row, column and region has its quota, and keep every star out of the eight cells around every other star.
- Each row, each column and each outlined region holds the same number of stars: one in a 1-star grid, two in a 2-star grid.
- Stars never touch each other, not even diagonally.
- Every puzzle has exactly one solution, and you can reach it by logic.
The 1-star version is the same puzzle people call the queens puzzle: one star (or queen) per row, column and region, none touching. The 2-star grid is the championship format, which some newspapers print under the name Two Not Touch: to play Two Not Touch online here, pick the 2-star grid of the day.
Try it on small grids
Three small Star Battle puzzles to get the feel. Hints work here too and explain each step.
Practice 1 · 5x5 1-star · Easy
Practice 2 · 6x6 1-star · Easy
Practice 3 · 6x6 1-star · Medium
Your first moves
Look for the smallest region. If it is two cells side by side, the star is in one of them, so the cells that touch both of them are empty: dot them. A region that sits entirely in one row takes that row's star, so the rest of the row is empty. Every star you place empties its eight neighbours and the rest of its row, column and region. Keep alternating between placing what is forced and dotting what is ruled out.
A worked example, step by step
Our solver finished this Star Battle (6x6 1-star) in 20 steps. Every step names its technique; step through it on the board, or read the whole solve below.
All 20 steps
- Last cells left. The region with A4 needs 1 more star and has exactly 1 open cell left: A4.
- Stars never touch. Stars never touch, not even diagonally, so the 5 open cells around the star at A4 are empty.
- Full row, column or region. Row 4 already has its star, so its other open cells are empty.
- Full row, column or region. Column A already has its star, so its other open cells are empty.
- Region inside one line. The open cells of row 5 all belong to the region with D4, so those stars come from that region and it has no room for more: 4 cells empty.
- Last cells left. Row 6 needs 1 more star and has exactly 1 open cell left: B6.
- Stars never touch. Stars never touch, not even diagonally, so the open cell around the star at B6 is empty.
- Full row, column or region. Column B already has its star, so its other open cells are empty.
- Full row, column or region. The region with C2 already has its star, so its other open cells are empty.
- Last cells left. Column C needs 1 more star and has exactly 1 open cell left: C1.
- Stars never touch. Stars never touch, not even diagonally, so the 2 open cells around the star at C1 are empty.
- Full row, column or region. Row 1 already has its star, so its other open cells are empty.
- Region inside one line. The region with D2 fits inside row 3, so it takes the star of that line; the other open cell there is empty.
- A star here leaves no room. A star at E2 would leave row 3 without room for its star, so E2 is empty.
- Last cells left. Row 2 needs 1 more star and has exactly 1 open cell left: F2.
- Stars never touch. Stars never touch, not even diagonally, so the open cell around the star at F2 is empty.
- Full row, column or region. Column F already has its star, so its other open cells are empty.
- Last cells left. Row 3 needs 1 more star and has exactly 1 open cell left: D3.
- Full row, column or region. Column D already has its star, so its other open cells are empty.
- Last cells left. Row 5 needs 1 more star and has exactly 1 open cell left: E5.
Common mistakes
- Forgetting the diagonal: two stars that meet at a corner also touch.
- Counting a region's cells instead of its free cells: a dotted cell is gone for good.
- In 2-star grids, filling a region's first star and forgetting that the second one must not touch it.
Where Star Battle comes from
Star Battle was created by the Dutch puzzle designer Hans Eendebak for the 2003 World Puzzle Championship in the Netherlands, and the 2-star 10x10 grid is still the standard championship size. The 1-star version on small grids became an everyday puzzle much later and is often called the queens puzzle.