Tango strategy: 12 solving techniques

Twelve ways to find the next sun or moon, graded from beginner to expert, each with an example and a practice row to try.

Think in lines

Almost every move in Tango comes from looking at a single line: one row or one column of six cells, together with the = and × clues between those six cells. When you fill a cell, it also belongs to a crossing line, and that line may now give you the next move. Solving is that loop, repeated until the board is full.

Every Better Tango puzzle can be solved with the twelve techniques below, without guessing. Three facts about a single line do most of the work:

It holds exactly three suns and three moons.
It never has three identical symbols in a row.
Only 14 arrangements satisfy both rules.

If you are new to the rules, start with how to play Tango.

Find your level

The techniques are grouped by how much of the line you need to take in to see them. Start where the moves still take you a moment, and work up.

In the diagrams, the cells to look at are tinted and the cells you can fill have a dashed outline. Cells are numbered from the left. Every example is drawn as a row, but each technique works the same way in a column. Each technique ends with a practice row: tap or click a cell to cycle through sun, moon and empty, or use the S and D keys.

Beginner: spot these at a glance

The answer sits right next to what you are looking at: a clue, a pair, or a full count.

1. Follow the clue

Beginner

The = copies the sun into cell 2. The × turns the moon in cell 4 into a sun in cell 5.

Spot: A filled cell joined to an empty cell by = or ×.
Place: Across =, copy the symbol. Across ×, place the opposite.
Why: It is the clue itself. Chains of clues work the same way: follow them one neighbour at a time, keeping the symbol across = and switching it across ×.

2. Complete the line

Beginner

Three suns are already placed, so both empty cells are moons.

Spot: A line that already has three suns or three moons.
Place: The other symbol in every remaining empty cell of that line.
Why: A line can hold only three of each symbol.

3. Block the pair

Beginner

Two moons side by side force a sun on each side.

Spot: Two identical symbols next to each other.
Place: The opposite symbol in the cell just before and the cell just after the pair.
Why: A third matching symbol next to the pair would make three in a row.

4. An = pair against the count

Beginner

Two suns are already used, so the = pair cannot be two more suns.

Spot: An empty = pair in a line that already has two of one symbol.
Place: The other symbol in both cells of the pair.
Why: The pair adds two matching symbols. Two more suns on top of two would make four.

This one often shows up together with another technique on the same cells. Here, the = pair at the edge and the sun at the far end tell you the same thing (technique 9). Counting is usually the faster way to see it.

Intermediate: look one cell further

The deciding symbol is one step away: across a gap, or just beyond a clue pair.

5. Fill the gap

Intermediate

Suns on both sides of a single empty cell force a moon between them.

Spot: Two identical symbols with exactly one cell between them.
Place: The opposite symbol in the gap.
Why: The matching symbol in the gap would complete three in a row.

6. An = pair beside a symbol

Intermediate

The empty = pair touches a moon, so both of its cells are suns.

Spot: Two empty cells joined by =, with a filled cell directly before or after the pair in the same line.
Place: The opposite of that neighbour in both cells of the pair.
Why: The = pair is two matching symbols. If they matched the neighbour too, the line would have three in a row.

Advanced: read the line end to end

These connect the two ends of a line, so you need to hold all six cells in mind.

7. Matching ends

Advanced

Suns at both ends force moons just inside them.

Spot: The same symbol in the first and last cell of a line.
Place: The opposite symbol in cells 2 and 5.
Why: The four middle cells hold one more sun and three moons. If that sun sat in cell 2, cells 3, 4 and 5 would be three moons in a row. The same goes for cell 5.

8. Edge pair, far end

Advanced

A pair of moons at the start of the line forces a sun at the far end.

Spot: Two identical symbols in the first two cells of a line, or in the last two.
Place: The opposite symbol in the cell at the other end.
Why: If the far end matched the pair, all three moons would be used, and cells 3, 4 and 5 would be three suns in a row.

9. Edge = clue, far end

Advanced

An = clue on the first two cells, and a sun at the far end: the pair is two moons.

Spot: An = clue joining the first two cells of a line (or the last two) while the cell at the opposite end is filled.
Place: The opposite of that far-end symbol in both cells of the = pair.
Why: It is technique 8 run backwards. A matching pair at the edge forces the far end to be the opposite, so a pair that matched the far end would break that rule.

Expert: count what the clues hold

Here you reason about cells you cannot fill yet: what a clue pair must contain, or which arrangements are still possible.

10. × pairs hold one of each

Expert

One × pair and two suns. The pair holds the third sun, so cells 5 and 6 are moons.

Two × pairs hold two suns and two moons, so the two cells outside them are opposite.

Spot: One or more empty × pairs that do not share a cell, in a line where the symbols outside those pairs already reach their limit.
Place: With one × pair, two placed suns mean every other empty cell is a moon. With two × pairs, one placed sun means the last outside cell is a moon. The same works with the symbols swapped.
Why: Whatever order its cells take, a × pair always contains exactly one sun and one moon. Each pair reserves one of the three suns, so you can count it before you know which cell holds it.

The pairs must be separate. Two × clues in a chain, such as cells 1 × 2 × 3, share cell 2, and only one of them counts as a reserved pair.

11. End and fifth cell

Expert

Suns in cells 1 and 5 force a moon in cell 6.

Spot: Matching symbols in cell 1 and cell 5, or in cell 6 and cell 2.
Place: The opposite symbol in the remaining end cell: cell 6, or cell 1.
Why: If cell 6 were a sun too, the three suns would sit in cells 1, 5 and 6, leaving cells 2, 3 and 4 as three moons in a row.

12. Line enumeration

Expert

When nothing else works, list every legal arrangement of a line that agrees with its filled cells and its clues, then fill any cell that is the same in all of them. This pays off in a line with two or more = or × clues.

You rarely need to write out every arrangement. Two shortcuts cover the cases that come up most.

Shortcut: the four-cell block

Cells 2 to 5 always hold two suns and two moons, so cells 1 and 6 must be opposite.

Spot: An = and a × that share a cell, plus the cell just beyond the = end. Together they make a block of four.
Place: Opposite symbols in the two cells outside the block.
Why: The = pair matches, say two suns. The × makes the next cell a moon, and the cell before the pair must also be a moon to avoid three suns in a row. The block is always balanced, two and two, so the remaining two cells share one sun and one moon.

Only two arrangements survive in this example, and both put a moon in cell 6:

Shortcut: separate = and × pairs

One sun, a × pair and a separate = pair settle the whole line.

Spot: Separate = and × pairs in one line, with a filled symbol outside both pairs.
Place: The opposite of that filled symbol in both cells of the = pair.
Why: The × pair uses one sun and one moon. With the sun in cell 1, only one sun is left, so the = pair cannot be two suns: it is two moons. That makes three moons, so cell 6 is a sun. Finally, a moon in cell 3 would sit beside the two moons, so cell 3 is a sun and cell 2 a moon.

All 14 legal lines

These are the only ways to fill six cells with three suns, three moons and no three in a row. They come in pairs: swap every sun for a moon to get the partner.

A solving routine

Work from the quick checks to the slow ones. Most moves come from the first two steps.

Follow every = and × clue that touches a filled cell.
Look for lines with three of a symbol, pairs side by side, and single gaps.
Check the edges: = pairs beside a symbol, matching ends, edge pairs, and edge = clues.
Count × pairs as one sun and one moon each.
Check cell 1 against cell 5, and cell 6 against cell 2.
Only then work through a line with two or more clues, using the shortcuts above.

After every placement, look at the crossing line through that cell. That is where the next move usually is. If you are stuck, the Hint button in the game shows the next step, and Learn why walks through the reasoning.

Put the techniques to work on a fresh board.

Play Tango