Binary Puzzle (Takuzu)

How to play Binary Puzzle

Binary Puzzle, also called Takuzu or Binairo, is a logic puzzle for one player. The square grid has an even size. Some squares already hold a 0 (blue) or a 1 (orange). You fill in all the others.

Goal

Fill every empty square with a 0 or a 1 so that three rules hold:

• No three in a row. The same digit may never appear three times next to each other, across or down. Two side by side is fine.
• Equal counts. Every row and every column has as many 0s as 1s. On a 6×6 grid that is three of each.
• No twins. No two rows are the same, and no two columns are the same.

Every puzzle here has exactly one answer, and you can always find it by logic.

Step by step

1. Tap an empty square to place a 0. Tap again for a 1, and once more to clear it. Right-click goes the other way.
2. You can also select a square and use the 0, 1 and Erase buttons under the grid.
3. On a keyboard, move with the arrow keys and type 0 or 1. Space cycles and Backspace clears.
4. Starting digits are a little darker and have a small line under them. They cannot be changed.
5. Tiles that break a rule get a red outline: three in a row, too many of one digit in a line, or two equal full lines.
6. Press Undo to take back a move.

Levels

Easy is a 6×6 grid that you can solve with the three basic patterns below. Medium is 8×8 and sometimes needs the “no twins” rule. Hard is 10×10 with fewer clues, where you must think a step ahead.

End of the game

The puzzle is solved when every square is filled correctly. The timer stops and shows your time, and your game is saved in this browser until you finish. For a different grid challenge, try Sudoku.

Strategy tips

• Close the pairs. Two equal digits side by side, like 0 0, must have the other digit on both ends: 1 0 0 1.
• Fill the gaps. A gap between two equal digits, like 1 _ 1, must hold the other digit: 1 0 1.
• Count each line. When a row already has all its 0s, every empty square in it is a 1.
• Watch out for three. If a line needs one more 1 and placing it in one spot would force three 0s together, that spot must be a 0.
• Compare almost full lines. If a row has two empty squares and matches a full row everywhere else, fill the two squares the other way round.
• Switch between rows and columns. Every new digit helps the crossing line, so check both after each move.