When You're Stuck on a Star Battle Puzzle
Page 13 of How to Solve Star Battle Puzzles.
These puzzles are made to be solved by logic alone. Being stuck means there is a move that you have not spotted yet. It does not mean that you have to guess.
A checklist
Work down this list. Go back to the top whenever you place a mark. The moves are in the order that most players find them, from easiest to hardest. Each one links to its page when the page exists.
- Star neighbors. Does a star have squares around it that still have no dot?
- Finished. Does a row, a column or a region hold all its stars? Dot its open squares.
- Last squares. Does a row, a column or a region have as many open squares as stars left? Each one is a star.
- Region inside a line. Are all the open squares of a region in one row or column?
- Line inside a region. Are all the open squares of a row or column in one region?
- Tight squeeze. In a two-star or three-star puzzle, count the open squares in a line. Stars cannot sit side by side, so a group of side-by-side squares holds fewer stars than it has squares.
- Squeezed pair. The same count, for a group of two squares. Rule out the squares directly beside the pair in the next lines.
- Only one fit. Does a region have only one way to fit its stars?
- Every option agrees. Try each way that a small region fits its stars. For a bigger region, test one square.
- 2×2 blocks. A 2×2 block holds at most one star. Can you cover the open squares of a region with one block for each star left?
- Crowding. Suppose that a square holds a star. Does that leave a region with no place for its stars?
- Regions inside lines. Are N regions inside N rows or N columns?
- Sub-regions. Is there part of a region that must hold a star? What does that rule out?
In a one-star puzzle, the app's hints use steps 1 to 5, 7, 9, 11 and 12. Steps 6, 8, 10 and 13 matter from two stars up. From one star to two explains what changes in the counts.
Use a hint
In the app, a hint names the move, says why it works, and shows you the squares. Read the reasoning before you go on. Next time, the same step is easier to spot.
If a hint makes no sense, there may be a mistake on the board. The app can find mistakes and erase them for you.
Look ahead
There is one more move, for the very last resort. Look ahead says: suppose that a square holds a star, or that it does not. Follow that for a few steps. If a row, a column or a region then cannot hold its stars, the opposite is true.
You will almost never need it. If you are stuck, go through the checklist again. A move that you passed over is much more likely than a puzzle that needs Look ahead.
Practice on puzzles like these in our Star Battle Puzzles app, for iPhone, iPad, Mac and Android.
