Star Battle is a logic puzzle about placing stars. Every row, every column and every region of the grid must hold the same number of stars (one on small grids, two on bigger ones), and no two stars may touch, not even at a corner. It’s also called Two Not Touch.
The rules
Place stars so that:
- Every row, every column and every region holds the same number of stars. On a one-star puzzle, that’s exactly one in each. On a two-star puzzle, exactly two.
- No two stars touch, side by side, above and below, or corner to corner.
You can also cross out squares you know are empty. It helps more than you’d think: most of solving Star Battle is crossing squares out.
What breaks a rule
Stars touching. Even corner to corner isn’t allowed:
Too many stars in a row (or a column):
Too many stars in a region, even when they’re in different rows and columns:
In the game, stars breaking a rule get a red ring, and a row, column or region that no longer has room for its stars turns red.
A puzzle from the game, solved
This is the first level in the game: Easy level 1, a 6×6 with one star in each row, column and region.
It takes 16 steps. Here are the first three.
Step 1: a region inside one row
Region d (the short one in row 4) is just two squares, both in row 4. Its star must be one of them, so row 4’s star is in region d. The other four squares of row 4 are empty.
Step 2: one square left
Region c had three squares, and two of them were in row 4. They’re now crossed out, so its star goes in the last one: row 3, column 2.
Step 3: around the star
Stars never touch, so every square around the new star is empty.
The rest
The same ideas finish it. In all, it takes 10 steps from rows, columns and regions that are finished or down to their last square, 4 rounds of crossing out around a star, and 2 from a region or line confined inside another.
Where to start in any puzzle
Look at the smallest regions first. A region of one square is a free star: 14 of the 50 Easy levels and 22 of the Medium ones start that way. A small region that lies inside one row or column fixes that line’s star, clearing the rest of it; that’s the first move on 31 Easy levels and 22 Medium. On two-star puzzles, start by asking where a star in a small region would leave no room for its second star: 34 of the 50 Hard levels open that way.
Common mix-ups
- Corners count. Stars can’t touch diagonally either.
- Regions count as much as rows and columns. Two stars in different rows and columns can still be in the same region.
- Crossing out is half the game. Most moves don’t place a star; they rule squares out.