How to Play the Sun and Moon Puzzle (Takuzu): Rules and Tips
November 2, 2026
The Sun and Moon puzzle is a logic puzzle where you fill a grid with two symbols. It is known around the world as Takuzu or Binairo, and some newspapers call it a binary puzzle because it was first played with 0s and 1s. In Grid Ritual it’s the second puzzle of the morning, called Sun & Moon.
Like all our puzzles, every grid has exactly one answer, and you never need to guess.
The rules
Fill every empty square with a sun or a moon so that:
- Every row and every column has the same number of suns and moons. On a 6 × 6 grid, that’s 3 suns and 3 moons in each line.
- There are never three of the same symbol in a row, across or down. Two suns side by side are fine. Three are not.
- Squares with a darker background are given and can’t be changed.
How to play in Grid Ritual
Tap an empty square to place a sun. Tap again for a moon. Tap once more to clear it.
5 tips to solve any grid
1. Look for pairs
When two suns sit side by side, the squares on both ends of the pair must be moons. Otherwise you’d have three suns in a row. This is the most useful trick in the puzzle, and it works for moons too.
2. Look for gaps
If you see a sun, an empty square, and another sun (sun, gap, sun), the gap must be a moon. Again, a sun there would make three in a row.
3. Count each line
On a 6 × 6 grid, once a row has 3 suns, every other square in that row must be a moon. When a row is almost full, count what’s missing.
4. Try a square in your head
When a row needs just one more sun, picture the sun in each empty square, one at a time. If a spot would force three moons together somewhere else in the row, the sun can’t go there. Cross that spot off in your mind and try the next. This takes a little practice, but it cracks most of the harder grids.
5. Check across and down
Every square belongs to a row and a column. When you’re stuck on a row, look at the columns that cross it. A clue that’s hidden in one direction is often obvious in the other.
Why people love it
The Sun and Moon puzzle feels calm and orderly. The rules fit in one breath, the grids are small, and each square you fill makes the next one easier. If you enjoy LinkedIn’s Tango, you’ll feel right at home: it’s the same family of puzzle.
