How to Play Tango: The Complete Rules Guide

Tango is a 6×6 sun and moon logic puzzle. The rules take about a minute to learn and a lifetime of coffee breaks to get fast at. Here is everything that governs the board, with worked examples.

The goal

Fill all 36 cells of the grid with either a sun or a moon. A puzzle starts with a handful of symbols already placed and a scattering of = and × clues sitting on the edges between cells. Your job is to work out the rest. Every properly built puzzle has exactly one valid solution, and you can always reach it by pure deduction — guessing is never required and never helps.

The four rules

Rule 1 — Balance: three suns and three moons per line

Every row and every column must end up holding exactly 3 suns and 3 moons. This is the rule that does most of the heavy lifting late in a puzzle: the instant a line contains three of one symbol, every remaining empty cell in that line is forced to the opposite symbol.

Rule 2 — No three in a row

You may never have more than two identical symbols touching each other in a straight line, horizontally or vertically. Two in a row is fine. Three is illegal. This rule is what makes Tango feel tight — it constrains the board long before the balance rule kicks in.

Two suns already sit side by side, so the cell immediately to their right must be a moon. There is no choice involved.

Rule 3 — The = sign means "same"

When two neighbouring cells are joined by an =, they must contain the same symbol. If either one becomes known, the other is immediately known too.

Rule 4 — The × sign means "different"

When two neighbouring cells are joined by an ×, they must contain different symbols. One sun, one moon — in whichever order the rest of the board demands.

A worked example

Suppose a row currently reads: sun, empty, sun, empty, empty, moon.

Start with rule 2. Cell 2 sits between two suns. If you placed a sun there you would create three suns in a row, so cell 2 must be a moon. That is the "sandwich" pattern, and it is the single most useful shape to train your eye on.

Now count. The row holds two suns and two moons, with cells 4 and 5 still empty. Rule 1 says the finished row needs three of each, so those two cells must be one sun and one moon. Which way round depends on the columns crossing them — and that is exactly how a Tango puzzle chains: a deduction in one line unlocks a deduction in another.

Three mistakes new players make

• Guessing when stuck. There is always a forced move available. If you cannot see one, you have not finished scanning — re-check the lines that are closest to full.
• Ignoring the clue signs after the opening. Players use the = and × clues to get started, then forget them. But a clue that was useless at the start becomes decisive the moment one of its two cells gets filled.
• Only counting one symbol. A line with three moons is just as finished as a line with three suns. Watch both.

Frequently asked questions

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