Two stars, everywhere
Star Battle is a placement puzzle on a grid divided into coloured regions. Here the board is always 9×9 with nine regions, and every row, every column and every region needs exactly two stars. No two stars may touch, not even at a corner. Every star is boxed in by three counts at once.
Since a row needs two stars that cannot sit side by side, every row and column has at least one empty cell between its pair. A star also rules out all eight cells around it, which reaches into the rows above and below. Most of the solving is about tracking those ruled-out cells, which is what the × mark is for.
Small regions first
Start with the smallest regions.
- Tiny regions. A region of three cells in a row can only fit two non-touching stars at its two ends. Place both.
- Compact shapes. A 2×2 square region cannot hold two non-touching stars at all, so you will not see one. But a region shaped like a short L or a 2×3 block has only a few legal pairs. List them and look for cells that appear in every pair, or in none.
- Cells shared by every option. If every legal pair in a region rules out the same outside cell, because it touches a star in all of them, mark that cell ×.
Counting across rows and regions
The deepest technique in Star Battle is counting. It works because the totals are fixed.
Say two regions sit entirely inside rows 1 and 2. Those two rows need four stars between them, and those two regions need four stars between them. So the regions use up every star the rows have. Any cell in rows 1 and 2 that belongs to a different region can be marked ×.
The same idea works the other way. If three regions together are confined to three columns, those columns' six stars all go into those regions, and every other cell in those columns is ruled out. On a 9×9 board, look for one, two or three regions packed into the same number of rows or columns. Spotting them is often the key step on Hard.
A worked example
Say a region on the left edge is three cells tall in a single column, rows 4 to 6. Two non-touching stars in three cells stacked in a line must take the top and bottom: rows 4 and 6. Place them. Now cross the eight cells around each, which marks most of column 2 in rows 3 to 7 as ×. Column 1 now has its two stars, so the rest of column 1 is crossed too. Row 4 and row 6 each have one star and need one more, somewhere to the right, at least two columns away. That has already removed a large part of the board.
Habits that keep you out of trouble
- Mark every neighbour. After placing a star, put × on all eight cells around it straight away. Diagonal touches are the most common way to go wrong.
- Close full lines. When a row, column or region has its two stars, cross every remaining cell in it.
- Watch for red. A cell turns red when two stars touch or a line or region has too many. Clear the star rather than piling more on.
- Do not star on a hunch. Every board has exactly one solution, so every star can be proved. If you cannot say why a star goes somewhere, leave it.
Moving through the difficulties
The board size never changes. What changes is how many stars are revealed at the start: six on Easy, three on Medium and none on Hard. The given stars are fixed and cannot be removed.
Easy is a good place to practise marking neighbours and closing full lines, since the givens already cross off much of the board. Medium leaves more of the board open, so small-region analysis starts to matter. On Hard, with no givens, the row and region counting technique becomes essential.
The hint places a missing star or removes one that does not belong. If you want a gentler start with the same no-touching idea, Queen Zones at /games/queen-zones uses one piece per row, column and region instead of two.
