How to Solve Star Battle Puzzles

A Star Battle puzzle gives you a grid cut into regions. You place stars by logic alone. There is no guessing. Every move in this guide follows from the rules, and the guide checks each mark against the real solution.

Queens and Meowdoku are one-star Star Battle puzzles. Two Not Touch is the two-star kind. If you can solve one of them, you already know most of the rules here.

The rules

Place stars on the grid so that:

Every row, every column and every region holds the same number of stars. A one-star puzzle holds one star in each. A two-star puzzle holds two. A three-star puzzle holds three.
No two stars touch. That includes squares that touch only at a corner.

A region is an area of the grid with a heavy line around it. Each region has its own color in the app. This guide uses the same colors.

An 8×8 one-star puzzle with 8 regions. Rows and columns are numbered from 1 at the top left, so the text can say "row 4" or "column 7".

In this puzzle, each row, each column and each region needs exactly one star. Eight stars in all.

Marking squares

You use two marks:

A star goes on a square that must hold a star.
A dot goes on a square that cannot hold a star. Solvers say that you rule out the square.

Dots are notes to yourself. They save you from checking the same square twice. Most of solving a Star Battle puzzle is ruling out squares until each region has only one place left for its star.

A star, with dots on the squares that it rules out: the eight squares around it, and the rest of its row and column.

One puzzle, start to finish

The app gives a hint when you are stuck. Each hint names a technique, says why it works and shows you the squares. The hints below are from the app. They solve this puzzle in 22 steps, and 19 of the steps use only three basic moves. The rest of the guide teaches the other moves.

Last squares

Look for a region with one open square left. An open square is a square with no mark yet. A region needs a star, so that square must hold it.

Last squares: This region has one open square and one star left. That square must be a star.

This small region is one square, at row 3, column 2. It must hold a star. The new star is in blue.

Star neighbors

Stars cannot touch. So a new star rules out the squares around it. The app puts these dots in for you when you place a star. If some go missing, for example after you erase, a Star neighbors hint puts them back.

Star neighbors: Rule out the squares around this star.

The eight squares around the star get dots. The new dots are in blue.

Finished

A row, column or region needs only so many stars. Once it holds them all, rule out its other open squares.

Finished: This row has all its stars. Rule out its open squares.

Row 3 holds its star, so the rest of row 3 gets dots. The new dots are in blue.

The same works for a column or a region.

Finished: This column has all its stars. Rule out its open squares.

Column 2 holds its star, so the rest of column 2 gets dots. The new dots are in blue.

When the basic moves run out

The three basic moves now stop for a while. Every region still has two or more open squares. The next hints use two more moves. Each has its own page in this guide.

The first is Region inside a line. All the open squares of one region are in one row or column. That line needs a star, and the region supplies it. So the rest of the line cannot hold one.

Region inside a line: All the open squares of one region are in this row. So the stars left in this row must all be in that region. Rule out the rest of this row.

Both open squares of this small region are in row 8. Its star is in row 8, so the rest of row 8 gets dots. The new dots are in blue.

The second is Line inside a region. It is the same idea turned around. All the open squares of one line are in one region. The region supplies that line's star, so the rest of the region cannot hold one.

Line inside a region: All the open squares of one row are in this region. So this region holds all the stars of that row. Rule out the rest of this region.

Every open square of row 1 is in the big region at the top. That region gets its star from row 1, so the rest of the region gets dots. The new dots are in blue.

One more Line inside a region follows at hint 7. After that, the three basic moves finish the puzzle.

The basic moves again

Here is Last squares once more, now on a column.

Last squares: This column has one open square and one star left. That square must be a star.

Column 8 has one open square left, at row 1. It must hold a star. The new star is in blue.

From here the puzzle repeats the same three moves. Place a star, rule out the squares around it, finish a row, column or region, and look for the next last square.

The last star, after 22 hints. Each row, column and region holds one star, and no two stars touch. The new star is in blue.

What comes next

The guide goes from one star to three, in the order below. Pages without a link are coming soon.

Coming from Queens or Meowdoku? Start with Regions inside lines. Playing Two Not Touch? Jump to From one star to two.

Part 1: One star (8×8 and 10×10)

Star neighbors, Finished and Last squares: the three basic moves
Region inside a line and Line inside a region: the easy forms
Regions inside lines: the move that hard Queens and Meowdoku boards need
Every option agrees: a region with two or three ways to place its stars
Crowding: the move for hard one-star puzzles

Part 2: Two stars (10×10 and 12×12)

From one star to two: what changes
Tight squeeze and Squeezed pair: count open squares against stars left
Only one fit: the common small region shapes
2×2 blocks: a 2×2 block holds at most one star
Sub-regions: parts of a region that must hold a star

Part 3: Three stars (14×14, only in our app)

From two stars to three: what changes
A complete 14×14 three-star solve

Reference

When you're stuck: the techniques as a checklist
Names other guides use: a table that maps their names to ours

Practice on puzzles like these in our Star Battle Puzzles app, for iPhone, iPad, Mac and Android.