Star Battle

One star per row, column, and region. No two stars adjacent.

About

Star Battle 1★ on an 8×8 grid with region partition. Place stars so that each row, each column, and each region contains exactly one star, and no two stars are orthogonally or diagonally adjacent. Three count constraints and one local-adjacency constraint — pure exact-cover deduction, no global connectivity or arithmetic.

How to play

Arrow keys move the cursor. Space toggles a star on the cursor cell. X toggles a 'no-star' annotation. Win when each row, each column, and each region contains exactly one star, and no two stars are adjacent — including diagonally.

Features

• 8×8 grid with region partition
• Exact-cover deduction (1★ variant)
• Region/row/column count constraints
• Local adjacency constraint (no king-move neighbors)
• Star and 'no-star' annotation modes
• Unique-solution generation

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