Star Battle
One star per row, column and region. Stars never touch.
How to play Star Battle
The board is cut into coloured regions by bold lines. You place stars under three rules.
- Each row has exactly one star.
- Each column has exactly one star.
- Each region has exactly one star.
On top of that, no two stars can touch, and that includes corners.
Where to start
- Small regions first. A region with only two or three squares has very few places for its star. Try them before anything else.
- Each star rules out squares. Once one is down, its whole row and column, its region, and the eight squares around it are off limits. Dot them.
- Trapped regions. If a region sits entirely inside one row, that row's star belongs to the region, so the rest of the row can be dotted out.
- Borrowing. When two regions together occupy only two rows, those two rows spend their stars on them. Nothing else in those rows can hold one.
Questions
What are the rules of Star Battle?
Place stars so that every row, every column and every bold-outlined region holds exactly one star. Two stars may never touch, not even diagonally.
What do the dots do?
Tap a square once to drop a dot, which is your own note that no star goes there. Tap again for a star. Dots are never checked, so use them freely.
Are there bigger versions with two stars per row?
Yes, larger boards often use two stars per row, column and region. The boards here use one star each, which is the friendliest way in.
Does each board have one answer?
Yes. A solver checks that exactly one solution exists, and a second solver that reasons like a person has to be able to finish the board. Gentle boards need only confined regions. Tricky boards also need a group pattern, where several regions share the same few rows or columns.