Place one star in every row, column and region, with no two stars touching, not even diagonally
Star Battle is a placement puzzle on a square grid that is divided into outlined regions, as many regions as there are rows. You place stars so that every row, every column and every region holds exactly one star, and no two stars touch, not even at a corner. There is no arithmetic and nothing to guess: the regions' shapes and the no-touching rule are enough to work out where each star must go. Every grid here is new, comes in three sizes, and has exactly one answer, which a solver confirms before the puzzle appears.
Choose a size: easy is 5×5, medium 7×7 and hard 9×9, each with one star per row, column and region.
Press New puzzle. The thick lines and colours show the regions.
Tap a square once to place a star, a second time to turn it into a dot (your note that no star can go there), and a third time to clear it.
On a keyboard, move with the arrow keys, press Space to place or remove a star, X to place a dot, Backspace to clear and Ctrl+Z to undo.
With Show clashes on, a star that touches another star, or shares a row, column or region with one, turns red.
Place all the stars correctly and the puzzle ends, with your time saved as a best for that size.
Spatial reasoning and elimination. Most progress comes from noticing that a small region, or a region squeezed into one or two rows, forces its star into a narrow strip, which then rules out squares in the rest of that strip and around it. Solving well means holding several of these partial constraints at once and combining them, which exercises working memory, visual scanning of shapes and careful rule-following without any numbers.
Look for the smallest regions first. A region of two or three squares leaves very few places for its star.
Any square next to a star, including diagonally, can never hold a star. Dot those squares straight away.
If a whole region lies inside one row, that row's star is in that region, so dot every other square of the row.
Count regions against rows: if two regions fit entirely inside the same two rows, those two rows' stars belong to those regions and the rest of both rows is empty.
The same works for columns: if a whole region lies inside one column, dot every other square of that column.
Use dots freely. Most of a Star Battle solve is marking where stars cannot go.
Star Battle is a logic puzzle where you place stars on a grid split into regions. Each row, column and region must contain the same number of stars, here one each, and stars may not be in neighbouring squares, including diagonal neighbours.
No. A star may not be in any of the eight squares around another star.
Dots are notes. A dot marks a square where you have worked out that no star can go. They do not count toward the answer, but they make the next deductions easier to see.
Yes. After the generator places the stars and draws the regions, a solver counts every possible answer. While there is more than one, a square on a region's edge is moved to a neighbouring region and the count is checked again. The puzzle is shown only when exactly one answer remains.
5×5 (easy), 7×7 (medium) and 9×9 (hard), each with one star per row, column and region. Larger grids have more regions to balance against each other.
No. Every puzzle has one answer that follows from the rules, and careful elimination finds it.
It is free with no sign-up. Your best time per size, the number of puzzles you have solved and the Show clashes setting are saved in this browser only.