How to Play Usowan
Usowan is a Nikoli-style logic puzzle where you shade cells on a grid divided into rooms. The twist? One clue per room is a liar!
- Number clues: Each number shows how many of its orthogonal (up/down/left/right) neighbors should be shaded black.
- The liar rule: In each room (area bounded by thick borders), exactly one clue number is wrong. Part of the puzzle is figuring out which!
- No adjacent blacks: Shaded cells cannot touch horizontally or vertically.
- Connected whites: All unshaded cells must form a single connected group.
Tips and Strategy
- Start with clues that have value 0: they guarantee no black neighbors, helping you mark cells white.
- Use the no adjacent blacks rule to eliminate impossible shading positions.
- If a room has two clues that conflict, one of them must be the liar.
- Check white connectivity periodically: isolated white islands mean you have over-shaded.