Star Battle
Puzzle, Logic · Updated
Star Battle is a logic puzzle with three short rules and a lot of room to think. A square grid is split into coloured regions, and you place stars so that every row, every column and every region holds the same number of them, with no two stars touching. This version makes a new puzzle whenever you want one, offers a daily puzzle, and runs in your browser on a phone, a tablet or a computer.
How to play
Choose 1 star or 2 stars, then a board size. In the 1-star puzzles each row, column and region needs exactly one star, and the stars appear as crowns. In the 2-star puzzles each one needs two.
- Stars may never touch, not even diagonally.
- Every puzzle has exactly one solution, so it can always be solved by logic.
- When the last star is in place and nothing breaks a rule, the puzzle is solved.
On a touch screen or with a mouse, tap a cell once to mark it with a cross, tap again to place a star, and tap a third time to clear it. Drag across empty cells to cross out several at once. On a keyboard, the arrow keys move the highlight, Space cycles the cell, X marks a cross, S places a star and Z undoes. Stars that break a rule turn red straight away.
How to solve it
- Small regions first. A region with three or four cells can only hold its star in a few places, and those places often share a row or column.
- Every star clears its neighbours. Place a star and cross out the cells around it. On a small board that alone settles a lot.
- Regions trapped in a line. If a region lies entirely within one row, the row’s star must be in that region, so every other cell in the row is empty. The same works for columns and for pairs of regions in two rows.
- Think in crosses. Most of solving is proving where stars cannot go. When a row has only one cell left without a cross, the star goes there.
Daily, unlimited and board sizes
The 1-star puzzles come in 7×7, 8×8 and 9×9; the 2-star puzzles in 8×8, 9×9 and 10×10. Daily gives everyone the same puzzle for the day in each mode and size. New makes another puzzle straight away, as many as you like. Your best time for each mode and size is saved on this device, and the timer pauses when you switch tabs.
Who it is for
A 1-star puzzle takes a few minutes, which makes it a good daily habit; a 10×10 two-star puzzle is a proper challenge. If you like number logic, try Sudoku and its hard puzzles. The 1-star mode also has its own page: the Queens puzzle.
How to get a high score
- Start with the smallest region. A region of only a few cells leaves the fewest places for its stars.
- Cross out every cell around a star. Stars can never touch, not even diagonally, so a star clears up to eight cells at once.
- When a region sits entirely inside one row or column, that row or column is taken. Cross out every other cell in it.
- Look for two regions that fit inside the same two rows. Together they fill both rows, so every other cell in those rows is empty.
- Mark crosses as you go. Most of the puzzle is working out where stars cannot be.
Questions
What are the rules of Star Battle?
Each row, each column and each coloured region must hold the same number of stars — one in the 1-star puzzles and two in the 2-star puzzles. Stars may not touch each other, not even at a corner.
Is this the same as the Queens puzzle?
The 1-star version is. Queens puzzles use crowns instead of stars and call them queens, but the rules are identical — one per row, column and region, never touching. The crowns appear when you choose 1 star.
Does every puzzle have one solution?
Yes. Every puzzle is checked by a solver when it is made, and it is only shown if it has exactly one solution, so you never need to guess.
What is the daily puzzle?
Daily gives everyone the same puzzle for the day for each mode and board size. New makes a fresh puzzle whenever you want one, so there is no limit on how many you can play.
How do hints work?
A hint removes a star that is in the wrong place. If all your stars are right, it places the next correct one. Puzzles solved without hints count towards your best time.
Are my best times saved?
Yes. Your best time for each mode and board size is kept on this device. There is no account or sign-up.
