Star Battle puzzle: rules and how to solve one
A Star Battle puzzle is a logic puzzle on a grid of colored regions: place one star in every row, every column and every region, and no two stars may touch, not even diagonally. Some people know the one star version as a queens puzzle. Brewdoku is that puzzle with coffee cups on café tables.
Try one now
Today’s Daily Brew is free to play in your browser. No account, no download.
The rules
The whole puzzle fits in three rules. In Brewdoku a star is a cup and a region is a table.
- Every row holds exactly one cup, and so does every column.
- Every colored table holds exactly one cup.
- Two cups never touch, not even on a corner.
There is no math and there are no words. A good puzzle has exactly one solution and you can reach it with logic alone. Every Brewdoku board is checked for both before it ships.
How to solve it, step by step
You solve a Star Battle by crossing out the spots where a cup cannot be. These six ideas solve most boards, from the easiest to the hardest.
Start with the smallest table
A table with one spot is a free cup. A table with two or three spots is the next best place to look. Once a cup is down, cross out the rest of its row, its column, its table and the eight spots around it.
A table that fits in one row
If every spot of a table lies in the same row, that row’s cup must be in that table. Cross out the rest of the row. The same works for a column.
A row that fits in one table
The other way around: if every open spot of a row belongs to one table, that table’s cup is in that row. Cross out the table’s spots in other rows.
Two tables in two rows
When two tables together fit inside two rows, those two rows are full: their cups are in those tables. Cross out every other spot in the two rows. It also works with three tables in three rows, and with columns.
The spot that blocks a whole table
Look at a small table and ask: is there a spot outside it that touches every open spot of that table? A cup there would leave the table empty, so cross it out.
Count, never guess
When you feel stuck, count open spots per row, column and table. The line with the fewest options is almost always where the next step hides.
Every technique in detail
Each one on its own page, with a real board from the game before and after the step.
- The last free spot
- A table that fits in one row
- The spot that blocks a whole table
- Two tables in two rows
- Three tables in three rows
- What if: follow a cup until it breaks
Learn it while you play
Brewdoku helps you learn these ideas as you go. Its hints come in three steps: where to look, why it works, and only then the move. 300 levels from small boards to 10x10, a new Daily Brew every day, and no clock unless you turn it on.
Questions about Star Battle
What is a Star Battle puzzle?
A Star Battle puzzle is a logic puzzle on a square grid split into regions. You place stars so that every row, column and region has the same number of stars, and no two stars touch, not even diagonally. In the one star version, which Brewdoku uses, that number is one.
Is Star Battle the same as a queens puzzle?
A queens puzzle on a grid of colored regions follows the rules of a one star Star Battle: one piece in every row, column and region, and no two pieces touch. Brewdoku uses the same rules, with cups for the pieces and tables for the regions.
Do you ever have to guess in Star Battle?
No. A well made Star Battle puzzle has exactly one solution and every step follows from the rules. If you feel you must guess, there is a spot you can still cross out.
Is Star Battle like sudoku?
It feels similar: a grid, a few fixed rules and pure deduction. Star Battle has no numbers. You only decide where a star goes and where it cannot go.
Where can I play Star Battle for free?
You can play one free puzzle a day in your browser at brewdoku.app/today. The Brewdoku app for Android has 300 levels and the same daily puzzle, free with light ads.
What size are Star Battle puzzles?
One star puzzles are usually between 5x5 and 10x10. Bigger boards with two or more stars per row exist too. Brewdoku goes up to 10x10 with one cup per row.