How to Solve Star Battle: Regions, Rows, and the Elimination Habit

Updated August 2026

Star Battle gives you a grid carved into irregular regions and asks for one star in every row, every column and every region, with no two stars touching — not even diagonally. The rules fit in a sentence, which fools people into solving by trial. Do it by elimination instead and the boards fall over in a predictable order.

Mark what cannot hold a star

The single most important habit is marking dead cells. Every time you place a star, immediately cross out all eight of its neighbours, plus the rest of its row, the rest of its column, and the rest of its region. That is a lot of the board gone in one stroke, and each crossing-out feeds the next deduction. Solvers who only mark stars stall constantly; solvers who mark exclusions never do.

Regions trapped inside a row or column

This is the workhorse technique. If an entire region sits within a single row, that region's star must be in that row — so the row's star is inside the region, and every cell of that row outside the region can be crossed out. The same works for columns, and for a region confined to two rows when you have two such regions.

The reverse is just as useful. If a row's remaining free cells all lie inside one region, then that region's star is in that row, so every other cell of the region can be crossed out. Sweeping for both directions after each placement is where most of the progress comes from.

Count the space, not the cells

Because stars cannot touch, a star occupies more than its own cell — it sterilises a 3×3 block. That means a narrow region or a thin corridor can hold fewer stars than its size suggests. When a region is a long thin strip, the possible positions are far more limited than they look. Ask not "how many cells are here" but "how many mutually non-touching cells are here".

Corners and edges resolve early

A region tucked into a corner has fewer neighbours to worry about but also fewer escape routes. Regions along an edge are frequently forced, because half of a candidate cell's blocking area falls off the board and the row and column constraints bite harder. Start your scanning at the edges and work inward; the middle usually resolves itself once the border is settled.

Two candidates in a line

When a region is down to two possible cells and both sit in the same row, you know that row's star belongs to this region even without knowing which cell it is. Cross out the rest of the row immediately. This "I do not know where, but I know the line" step is the deduction that most often breaks a stuck board, and it costs nothing to look for after every placement.

Never guess

A properly constructed Star Battle has exactly one solution reachable by these steps. If you feel like guessing, you have almost always skipped an elimination sweep. Go back and re-check each region against the rows and columns it touches — the board has changed since you last looked, and a region that spanned three rows a moment ago may now be confined to one.

A reliable order of attack

1. Cross out every cell touching a placed star, plus its row, column and region.
2. Find regions contained in a single row or column and clear the rest of that line.
3. Find rows or columns whose free cells all lie in one region and clear the rest of that region.
4. Look for regions with only one non-touching placement left and place the star.
5. Work edges and corners before the middle.
6. Repeat from step one after every star.

Run that loop and each star you place typically forces one or two more. The puzzle finishes in cascades, not in a slog.