How do you play the binary puzzle?
Fill every empty cell with 0 or 1 so that no three of the same sit in a row, each row and column holds as many 0s as 1s, and no two rows or columns are identical. The puzzle is also known as Takuzu or Binairo.
On ormgames the digits are clay pieces: a yellow sun for 1 and a sky blue moon for 0. If you prefer digits, turn on numbers with the 0/1 button. Darker cells are given at the start and cannot be changed.
What are the rules?
| No three in a row | Three suns or three moons may never sit side by side, across or down |
|---|---|
| Half and half | Every row and column has exactly as many suns as moons (four each on 8×8) |
| No twins | Two full rows may not be identical, and the same goes for columns |
| Solution | Every puzzle has exactly one solution, reachable by logic alone |
| Error marks | Red rings for three in a row or too many of one kind, red dashes for identical lines |
What do the sizes and levels change?
There are four sizes, 6×6, 8×8, 10×10 and 12×12, and the level sets how deep the logic goes. Each puzzle is generated fresh and only kept if a computer solver can finish it with the logic of that level, with no guessing.
- Easy: pairs, gaps and full counts are enough.
- Normal: some cells only follow from checking the ways a line can be finished.
- Hard: you also need the rule that a line cannot copy one that is already full.
Tips for solving faster
- Look for pairs first. Two suns side by side mean a moon on both ends.
- Fill the gaps. In sun, blank, sun the blank must be a moon.
- Count. Once a row has half its suns, every other cell in it is a moon.
- Work through nearly full lines. With three or four blanks there are only a few ways to finish, and any cell that is the same in all of them is settled.
- Compare with full lines. If a line with two blanks could turn into a copy of another, place the opposite.
Stuck? Press Hint. It fills one cell that logic settles right now and explains why in one sentence. If a piece you placed does not match the solution, the hint points to it first. Best times for each size and level are saved in this browser.