Tango: The Suns and Moons Balance Puzzle ☀️🌙

The rules

Fill every cell of a 6×6 grid with a sun or a moon, so that:

• each row and column has three of each, and
• no three identical symbols in a row, horizontally or vertically.

Some cells start filled, and some pairs of neighbouring cells carry a clue: = means they match, × means they differ.

The two deductions you need

Sandwich. Two identical symbols with a gap between them — sun, blank, sun — force a moon in the gap. Three suns in a row is illegal, so the middle can't be a sun. This is the single most common move in the game.

Pair extension. Two identical symbols side by side force the opposite symbol at both ends. Sun-sun means the cell before and the cell after are both moons. People reliably remember one end and forget the other.

Add the counting rule — once a line already has its three suns, every remaining cell in it is a moon — and you have everything the early levels need.

Equals and cross clues

The clue markers are what make the harder boards work. An = between two cells means whatever you deduce about one applies immediately to the other, which effectively glues them into a single unit for the counting rule: an = pair uses up two of a line's three slots at once.

A × pair always contributes exactly one sun and one moon to its line, which is often the deduction that finishes a row: if a row has one known sun and an × pair, the remaining free cells are forced.

About our version

99 levels on a curve that reduces the number of starting cells and clue markers as you climb. Tap a cell to cycle sun, moon, empty. Unlimited undo, hints, and every board verified to have a single solution.

It runs in your browser, works offline once loaded, needs no account, and costs nothing.

Questions people actually ask

Can there be three suns in a row?
Never — not horizontally and not vertically. Two in a row is fine, and in fact pairs are what most deductions hang off.

What do the = and × symbols mean?
They sit between two neighbouring cells. = means the two cells hold the same symbol; × means they hold different ones.

Is Tango the same as Binairo or Takuzu?
It's the same family. The three-of-each and no-three-in-a-row rules are shared; the = and × clue markers are what distinguish this variant.

Keep reading

• Crowns: The One-Per-Region Puzzle You'll Finish in Five Minutes 👑 — One rule you can learn in ten seconds, and deduction chains that run five steps deep. The best entry point into logic puzzles we have.
• Logic Puzzle Games: A Guide to the 12 in Go Brain 🧠 — Sudoku, Kakuro, Nonogram, Crowns and eight more. What separates a real deduction puzzle from a guessing game, and which to start with.
• Sudoku Online: How to Play and How to Get Faster 🔢 — Four difficulties, pencil marks, and a hint that teaches instead of just filling a square. Plus the three techniques that get you past Easy.