How to Play Star Battle: Rules and a First Puzzle
The rules of Star Battle in plain words, what "never touch" means, how to mark empty squares, and a first 6x6 puzzle solved move by move.
Star Battle is a logic puzzle on a square grid divided into regions. In the one-star version, you place one star in every row, every column and every region, and no two stars may touch, not even diagonally. You solve it by marking squares that cannot hold a star until each row, column or region has only one place left. A fair puzzle has exactly one solution and never needs a guess.
This guide is for complete beginners. It covers the rules, what "touching" means, how to mark empty squares and a first 6x6 puzzle solved move by move. When you have the basics, our Star Battle strategies guide takes you further. Squares are named by row and column from the top left: R2C3 is row 2, column 3.
The rules of Star Battle
Star Battle has four rules, and all of them hold at the same time:
- Every row holds the same number of stars.
- Every column holds the same number of stars.
- Every region (an outlined or coloured area) holds the same number of stars.
- No two stars touch, not even at a corner.
The number of stars depends on the puzzle. Puzzle Picnic's Stars uses one star per row, column and region, which is the easiest version to learn and the one this guide teaches. The rule there reads: place one star in every row, every column and every coloured region; stars never touch, not even at a corner.
Larger puzzles often ask for two or three stars. The puzzle first appeared at the 2003 World Puzzle Championship as a two-star puzzle, and in April 2020 the New York Times began printing a two-star version under the name Two Not Touch. Our post on where Star Battle came from tells that story. The thinking is the same with more stars; there is simply more to count.
One consequence of the rules is useful straight away: a one-star grid of 6 rows has 6 columns and 6 regions, and needs exactly 6 stars. Every row, column and region gets one, no more and no less.
What "never touch" means
In Star Battle, two stars touch if their squares share a side or a corner. So each star rules out all eight squares around it. In one-star puzzles it also rules out the rest of its row, the rest of its column and the rest of its region, because each of those can hold only one star.
Corners are the part people forget. Two stars that meet only at a corner still break the rule. If you play Battleship puzzles, it is the same no-touch idea as in why ships never touch, applied to single stars.
Marking empty squares
Marking a square as empty means writing down that it cannot hold a star. It is the main thing you do in Star Battle. Most of a grid ends up empty: a 6x6 puzzle has 36 squares and only 6 stars, so 30 squares get a mark. The stars appear when a row, column or region runs out of other options.
Good marking habits:
- Mark around every star at once. Its neighbours, its row, its column and its region. Do it before you look for the next star.
- Mark only what you know. A square is empty when a rule rules it out, not when it looks unlikely.
- Recount after every batch of marks. Each mark may leave some row, column or region with a single open square.
In Puzzle Picnic you tap a square once to mark it empty and twice to place a star, and you can drag to mark several squares. If two stars break a rule, they turn red and count as a mistake, so you see the problem straight away.
Your first puzzle, move by move
Here is a complete one-star 6x6 puzzle, the size of Puzzle Picnic's Easy level. Each letter is a region. Region A is the big one across the top; region F is a single square in the bottom-left corner.
Move 1: the one-square region. Region F is just R6C1, so its star must go there. Now mark: its neighbours R5C1, R5C2 and R6C2; the rest of row 6; the rest of column 1.
Move 2: region B. Region B is R2C1, R2C2, R3C1 and R4C1. Three of those are in column 1, which now has its star, so the only square left for B is R2C2. Place it and mark around it: the squares touching it, the rest of row 2 and the rest of column 2.
Move 3: a row that belongs to one region. Look at row 1: every square in it belongs to region A. Row 1 needs a star, so region A's star must be in row 1. That means no other square of region A can hold a star, and R3C4 and R3C5 can be marked.
Move 4: row 3 has one square left. Row 3 is now marked everywhere except R3C6, so its star goes there. Mark around it: R4C5 and R4C6 touch it, R1C6 and R5C6 share its column, and the rest of region C goes too.
Move 5: squares that both options touch. Row 4 now has two open squares, R4C3 and R4C4, and they are also the last two squares of region E. One of them holds a star. Both touch R5C3 and R5C4, so whichever it is, those two squares are ruled out. Mark them.
Move 6: row 5. Row 5 has only R5C5 left, so that is its star (and region D's). Mark around it, which rules out R4C4 and R1C5.
Move 7: the last two stars. Row 4 has only R4C3 left, and row 1 has only R1C4 left. Place both. Every row, column and region now has exactly one star, and none touch.
Look back at the moves and you will see four ideas: a region with one square left, a row or column with one square left, a row that lies inside one region, and squares that every remaining option touches. Those four ideas go a long way on small grids.
Five first moves to look for
When you open a new Star Battle, scan for these in order. Each one is quick to spot and safe to act on.
- The smallest region. A region of one square is a star. A region of two or three squares has very few options, and often only one survives the first few marks.
- A region that fits in one row or column. If every open square of a region lies in one row, that row's star belongs to the region, so the rest of the row is empty. The same goes for columns.
- A row or column that lies inside one region. This is move 3 from the puzzle above: the region's star must be in that line, so the rest of the region is empty.
- Squares that every option touches. When a row, column or region is down to two or three open squares, look for a square that touches all of them. It can never hold a star.
- Mark after every star. Neighbours, row, column, region. Then go back to step 1 with fresh eyes.
Our guide to squeezing regions has more on how region shapes force stars, and beginner mistakes to avoid covers the slips that cost the most time.
Grid sizes and star counts
Star Battle comes in many sizes, and the star count grows with the grid so that there is room to place every star without touching. On the two puzzle sites below, one-star grids run from 5x5 to 8x8, two-star grids are 10x10 and three-star grids are 14x14.
| Where you find it | Stars per row, column and region | Grid sizes |
|---|---|---|
| Puzzle Picnic's Stars | 1 | Easy 6x6, Medium 7x7, Hard 8x8, Expert 9x9 |
| KrazyDad | 1, 2 or 3 | 8x8 for one star, 10x10 for two, 14x14 for three |
| puzzle-star-battle.com | 1, 2 or 3 | 5x5, 6x6 and 8x8 for one star, 10x10 for two, 14x14 for three |
The KrazyDad sizes come from its Star Battle guide and the others from puzzle-star-battle.com. The New York Times' Two Not Touch uses two stars, and LinkedIn's Queens uses one: its help page gives the same one-per-row, column and region rule, with no two crowns in touching squares. If you came here from that game, our post on the Queens puzzle and Star Battle compares the two.
In Puzzle Picnic the grid grows by one row and one column at each level. Expert puzzles need reasoning about groups of regions together, and Hard ones sometimes do; the strategies guide explains how that works.
When you get stuck
Getting stuck in Star Battle usually means a mark is missing. Before you look for a new trick, work through this list:
- Check every star's neighbours. A missing corner mark is the most common reason a puzzle seems to stall.
- Count each row, column and region. For each one, how many open squares are left? Any with one left is a star. Any with two or three left is worth the "squares every option touches" check.
- Look at regions, not just lines. Beginners scan rows and columns and forget that regions are the third rule. Small regions are where most early stars come from.
- Never guess. A guess that happens to work teaches you nothing, and one that fails leaves you unsure which marks to trust.
If you are still stuck, a hint in Puzzle Picnic explains the next logical step rather than just filling a square, and you get three free hints a day. Reading why a square is ruled out is a fast way to learn a technique you have not met yet.
Frequently asked questions
Can stars touch diagonally in Star Battle?
No. Two stars may not share a side or a corner, so diagonal touching breaks the rule too. Each star rules out all eight squares around it.
How many stars go in each region?
The same number as in each row and column. In one-star puzzles, including Puzzle Picnic's Stars and LinkedIn's Queens, it is one per region. Two-star puzzles such as the New York Times' Two Not Touch put two stars in every row, column and region.
Do you ever have to guess in Star Battle?
Not in a well-made puzzle. A good Star Battle has exactly one solution, and there is always a next step you can prove from the rules. Every puzzle in Puzzle Picnic is checked by a solver to have exactly one solution that logic can reach.
Is Star Battle the same as Queens?
They share the same rules in the one-star form: one star (or crown) per row, column and region, none touching. The name Queens comes from the chess puzzle about placing queens, but in Star Battle a star only rules out the squares right next to it on a diagonal, not the whole diagonal.
What size Star Battle should a beginner start with?
Start with a one-star grid of 6x6 or smaller. You meet every basic idea on a small grid, and you can see the whole puzzle at once. Move up a size when you can solve the small ones without missing marks.
Where to go next
Solve three or four small grids using the five first moves above, saying each reason to yourself as you mark. Once you notice yourself spotting "this region fits in one row" without thinking, you are ready for the counting techniques in the Star Battle strategies guide.
The Stars page has the rules and a Play button. Easy is a 6x6 grid like the one above, so it is a good place for your first solo puzzle.