The three rules of Binero
Binero is played on a square grid where some cells are already filled in. Your goal is to complete all the others with one of two symbols, ○ (hollow circle) or ● (filled circle). They stand in for the 0s and 1s of classic Takuzu.
- Never three in a row. Two identical symbols may touch, three never can, horizontally or vertically.
- Equal numbers. On the daily 8×8 grid, every row and every column holds exactly four ○ and four ●.
- No duplicates. No two complete rows may be identical, and no two columns either.
The given cells are locked. They are chosen so that the grid has exactly one solution, which means no cell ever requires a guess.
The daily grid
Binero serves a new grid every day, the same for every player. On weekdays it is a medium 8×8 grid with 26 of its 64 cells given. On Sundays it stays 8×8 but reveals only 18 cells, so the deductions take longer to find.
There is also an easy level on a 6×6 grid, where each row holds three ○ and three ●. The rules do not change with the size.
How to fill in cells
Tap an empty cell and it cycles from ○ to ●, then back to empty. You can also select a cell and use the ○ and ● keys under the grid to place a symbol directly.
The other tools carry French labels in the game:
- Annuler (undo) takes back your last action, values and notes alike.
- Effacer (erase) clears the selected cell, value and notes.
- Notes switches to pencil mode: the ○ and ● keys then add a small mark to an empty cell without filling it.
- Joker reveals one cell of the solution and locks it, at the cost of a few points.
On a computer, the keyboard works too: arrow keys to move, 1 for ○, 2 for ●, Space to cycle the cell, N for notes, Backspace to erase and Cmd or Ctrl + Z to undo.
When is the grid checked?
Binero never flags a mistake mid-game. With only two symbols, saying a cell is wrong would give the answer away: it would have to be the other one. So the grid is judged only once every cell is filled.
If it is right, the game ends and your score appears. If it is wrong, the grid shakes and a message tells you the grid is complete but incorrect, without saying where the error is. Each failed check costs points, so review your grid before you fill the last cell.
Your first row, step by step
Take one row of an 8×8 grid with three given cells. Dots mark the empty cells:
○ ○ · · ● · ● ·
Step 1, the pair. The two ○ side by side at the start force a ● right after them, otherwise there would be three ○ in a row. The row becomes ○ ○ ● · ● · ● ·.
Step 2, the gaps. The 4th cell sits between two ●, so it must be a ○. The same goes for the 6th cell, also between two ●. You get ○ ○ ● ○ ● ○ ● ·.
Step 3, counting. The row already has four ○, the maximum on an 8×8 grid. The last cell is therefore a ●. Result: ○ ○ ● ○ ● ○ ● ●, which satisfies all three rules.
On a real grid you keep switching between rows and columns: each symbol placed in a row gives fresh information to the column that crosses it. When no pair, gap or count helps any more, the unique-rows rule takes over. It is covered in our Binero tips.
How scoring works
Your score, out of 1000, depends on three things: failed checks, jokers used and time. The day's difficulty then acts as a multiplier, so the Sunday grid is worth more. Score 750 or more and you earn three stars.
Jokers are unlimited. If the grid still has empty cells, a joker reveals one of them; if the grid is full but wrong, it reveals a wrong cell. That is the safest way out of a dead end.
What next?
Once the rules click, a handful of techniques will make you much faster: they are gathered in our Binero tips. For more daily puzzles in the same spirit, browse our pick of daily logic games.