How to play Tango
Tango is a deduction puzzle, not a guessing game. Master the rules, then learn five techniques and you'll solve most boards in under three minutes.
The rules
- Two symbols. Each cell holds either a sun or a moon.
- Balance. Every row and every column must contain the same number of suns and moons.
- No triples. Three of the same symbol in a row, horizontally or vertically, is illegal.
- Equals. An "=" between two adjacent cells means they hold the same symbol.
- Differs. An "×" between two adjacent cells means they hold opposite symbols.
- Unique. Every puzzle has exactly one solution, reachable without guessing.
Controls
- Tap / click an empty cell to cycle: empty → sun → moon → empty.
- Long-press (mobile) or right-click (desktop) cycles in reverse — useful when you just overshot.
- Arrow keys move the selection. S places a sun, M places a moon. Space or Enter cycles. ⌫ clears.
- Hint places one cell that's strictly deducible from your current board — so you learn the technique, not just the answer.
- Undo / Redo walk your full move history.
Five deduction techniques
1. The gap technique
Two of the same symbol with one blank between them: the blank must hold the opposite. A third sun in ☀ · ☀ would create a triple, which is illegal.
2. The doubles rule
Two identical symbols sitting next to each other force the cells immediately before and after to be the opposite. · ☀ ☀ · resolves to 🌙 ☀ ☀ 🌙.
3. Counting
When a row (or column) already has half its cells filled with one symbol, every remaining empty cell in that row must hold the opposite.
4. Uniqueness
No two rows or columns may end up identical. If completing a row one way would duplicate a finished row, choose the other.
5. Progressive deduction
Every cell you place changes the picture for its row, its column, and any cell linked by a = or × marker. After each move, scan again — a dead end thirty seconds ago is often a forced move now.
Ready?
Pick a board and put it into practice.