Takuzu is a binary puzzle: every cell holds one of two symbols, here a sun or a moon. Three short rules are enough to fill the whole grid, and the satisfaction comes from watching one forced cell lead to the next.
The rules
- Fill every cell with a sun or a moon.
- Each row and each column has the same number of suns and moons (three of each on a 6×6 board).
- No more than two identical symbols may sit next to each other in a row or column.
- An = between two cells means they are the same; a × means they are different.
Tap an empty cell to cycle through sun, moon and empty. Grey cells are given and cannot be changed. You can drag to paint the same symbol across several cells.
Technique 1: Close the pair
Two identical symbols side by side must be closed on both ends with the opposite symbol, otherwise you would get three in a row.
Technique 2: Fill the sandwich
If two identical symbols have exactly one empty cell between them, that middle cell must be the opposite symbol.
Technique 3: Count to balance
Once a line already holds its full share of one symbol — three suns on a 6×6 board — every remaining cell in that line must be the other symbol.
Counting also works one step earlier: if a row needs two more moons and only two empty cells are left, both are moons.
Technique 4: Read the signs
Signs connect cells even when both are empty. An = pair behaves like a single block: if the cell next to it is a sun, the pair cannot be suns (that would make three), so both cells are moons.
A × pair always contains one sun and one moon, so it counts as one of each when you balance a line.
Technique 5: Try one cell
On harder boards, pick an empty cell and imagine it is a sun. Apply the simple rules for a few steps. If you reach three in a row or an unbalanced line, the cell must be a moon. PuzzPik puzzles never need more than this one-step check.
Tips and common mistakes
- Check columns as carefully as rows — most mistakes hide vertically.
- Use “×” pairs for counting: they always contain one of each.
- Red outlines mean a rule is broken. Undo is free; hints add 15 seconds.
FAQ
Is Takuzu the same as Binairo or Tango?+
They are the same family of binary puzzles. PuzzPik uses the sun-and-moon style with = and × clues.
Do rows have to be unique?+
Not on PuzzPik. The classic “no two identical rows” rule is not used; the clues alone make each solution unique.
Why do weekend boards use 8×8?+
Bigger boards need longer chains of reasoning, so they appear later in the week.