How to play Tango

The complete rules of the 6×6 sun and moon puzzle, exactly as Better Tango checks them, plus the controls, hints, and friend challenges.

The goal

Tango is a logic puzzle on a 6×6 grid. Fill every empty cell with a sun or a moon so that all four rules below hold at once. Some cells start filled, and some neighbouring cells are joined by an = or × clue. Every puzzle has exactly one solution, and you can always reach it by reasoning. You never need to guess.

The rules

1. Three of each in every lineEach row and each column holds exactly three suns and three moons.
2. No three in a rowThree identical symbols may never sit next to each other, horizontally or vertically. Two in a row is fine.
3. = means the sameTwo cells joined by an equals sign hold the same symbol: both suns or both moons.
4. × means oppositeTwo cells joined by a cross hold different symbols: one sun and one moon.

Shaded cells are fixed clues. They are part of the puzzle and cannot be changed. Unlike some other binary puzzles, Tango has no rule against identical rows or columns: two rows may be filled exactly the same way.

How mistakes are shown

One second after your last edit, cells that break a rule get a dashed outline. A line with four of one symbol is outlined from end to end, three in a row outlines those three cells, and a broken = or × outlines both of its cells. A symbol that is legal so far but wrong for the final solution is not marked. Ask for a hint to find it.

Try it: a practice puzzle

This puzzle can be solved from start to finish with just five techniques from the strategy guide (follow the clue, complete the line, block the pair, fill the gap, and an = pair beside a symbol), and it needs every one of them. Click a cell to cycle through sun, moon and empty, right-click or long-press to go back, or use the arrow keys with S, D and Backspace. Hint points at the next cell you can work out and names the technique that cracks it.

The first moves

Seven moves in, every one of the five techniques has already appeared:

1. Follow the clue: row 4, column 4 is a moon, because the × below it flips the fixed sun in row 5.
2. Block the pair: row 2 ends with two suns side by side, so the cell before them, column 4, is a moon.
3. Fill the gap: row 2 now has moons in columns 2 and 4, so column 3 between them is a sun.
4. Complete the line: row 2 now has three suns, so its last empty cell, column 1, is a moon.
5. Fill the gap: row 6 has moons in columns 1 and 3, so column 2 is a sun.
6. Fill the gap: column 4 has moons in rows 2 and 4, so row 3 is a sun.
7. An = pair beside a symbol: in column 1, the = pair in rows 3 and 4 sits right below the moon in row 2, so both are suns.

The rest of the board falls the same way. The Tango strategy guide explains all five techniques, and the harder ones that come after them, with a practice board for each.

Why every puzzle is fair

Better Tango generates each puzzle in your browser. It first builds a complete, valid grid, then adds between four and ten = and × clues that are true for that grid. It removes symbols one at a time, keeping a removal only if the puzzle can still be solved step by step with the solver’s line techniques. Finally, an independent exhaustive search confirms that exactly one solution exists.

Each puzzle also gets a difficulty score: the solver adds up a weight for every technique it needs, and harder techniques weigh more. Scores up to 62 are Easy, up to 71.5 Medium, up to 80 Hard, and anything above 80 Very Hard. The level is shown above the board.

Pro mode

New puzzles are generated in Pro mode. Instead of taking the first solvable puzzle, the generator builds a batch of at least 32 candidates and keeps the highest-scoring one, and it only accepts a score above 80. That is why new boards are labelled Very Hard. Boards opened from a shared link keep their own difficulty.

Controls

Each cell cycles through three states: empty, sun, moon, and back to empty.

Mouse

Click a cell to cycle forward. Right-click to cycle backward. Hover over a cell and press S for a sun or D for a moon.

Touch

Tap to cycle forward. Press and hold for about half a second to cycle backward.

Keyboard

Arrow keys move between cells. S places a sun and D a moon. Space cycles (Shift + Space backward). Backspace or Delete empties a cell. Home and End jump to the ends of a row; with Ctrl they jump to the corners of the board. Tab leaves the board.

Undo

Ctrl + Z (⌘ + Z on a Mac) or the Undo button. Repeated changes to the same cell undo as one step.

Clear

Removes everything you placed and keeps the fixed clues.

Timer

Click the time to hide or show it. Switching to another tab or window pauses the clock and hides the board until you come back.

Your current game, undo history and settings are saved in your browser, so a refresh picks up where you left off. The header has a light and dark theme switch and a sound toggle.

Hints

Press Hint and the game marks one cell, shows the symbol that belongs there, dims the cells that do not matter, and names the reason in a sentence. The hint comes from the same step-by-step solver that checked the puzzle, so it is always a deduction you could have made from the board in front of you. If you have placed a symbol that does not match the solution, the hint points to that cell first and tells you what to change it to.

Learn why opens a short walkthrough. It tries the opposite symbol in the hinted cell, follows the consequences along that row or column until a rule breaks, and ends with a pattern to spot next time.

Sharing, challenges and replays

Share

Copies a link to the current puzzle, including the cells you have filled, or opens your device’s share menu.

Challenge

After solving, choose Challenge a friend and send the link. Your friend plays the same puzzle without seeing your time.

Race

When your friend finishes, Watch race plays both recordings side by side on the same clock. Send result lets your friend send the race back to you.

Replays

Every game is recorded. Save a replay from the completion screen, then rename, rewatch or delete it from the Replays button. Saved replays stay in your browser.

Challenge and result links are stored on the server so they work across devices. Anyone with a link can open it, and no account is needed.

Frequently asked questions

Is Better Tango free?

Yes. Better Tango is a free, independent browser game with no account, no download and no daily limit. Press New puzzle whenever you want another board.

Can I play Tango on my phone?

Yes. It runs in any modern mobile or desktop browser, and puzzles are generated on your device.

Can two rows be the same?

Yes. The only rules are the balance of three and three, no three in a row, and the = and × clues. Identical rows or columns are allowed.

Will I ever have to guess?

No. Every puzzle can be solved one forced step at a time, and the generator confirms there is exactly one solution.

How many clues does a puzzle have?

Between four and ten = and × signs, plus the fixed symbols.

What does the difficulty level mean?

It reflects how many deductions the puzzle needs and how advanced they are. See Why every puzzle is fair above, and the strategy guide for the weight of each technique.