How to play SunMoon
SunMoon is a binary logic puzzle solved by pure deduction. Here are the rules and the techniques that crack every board.
The rules
- Every cell holds one of two symbols: a ☀️ sun or a 🌙 moon.
- No three identical symbols may sit next to each other in a row or column.
- Each row and each column contains an equal number of ☀️ and 🌙.
- A = clue between two cells means they are the same; an ✕ clue means they differ.
- Some cells are given at the start (locked).
Controls
- Tap an empty cell → ☀️. Tap again → 🌙. Tap a third time → clear.
- Given (locked) cells can't be changed.
- Cells that break a rule are outlined in red.
Solving strategies
- Avoid triples. If two identical symbols sit side by side, the cells on both ends must be the opposite symbol.
- Fill the gaps. A single empty cell between two identical symbols must be the opposite (otherwise you'd make three in a row).
- Count to the balance. Once a row or column has all of one symbol placed (N/2), every remaining cell in that line must be the other symbol.
- Use the clues. An ✕ forces opposites, an = forces a matching pair — chain these with the no-triple rule for quick wins.