How to play Binary

The goal

The rules

• No more than two of the same digit next to each other in any row or column: 0 0 is fine, 0 0 0 is not.
• Every row and every column has as many 0s as 1s.
• No two rows are the same, and no two columns are the same.

Playing

• Tap an empty square to place a 0 (blue), tap again for a 1 (orange), and once more to empty it.
• The deeper-colored squares with a small dot are clues. They’re locked.
• Anything breaking a rule is outlined in red: three alike in a row, a line with too many of one digit, or a full line that repeats another.
• Undo takes back your last change. Hint fixes a wrong square, or fills in one you can work out next.

Tips

• Next to a pair, the digit must be the other one: 1 1 means a 0 on each side.
• Between two alike, the gap must be the other one: 0 _ 0 means a 1 in the middle.
• Once a line has all its 0s (or 1s), the rest of it is the other digit.
• On Hard, look at whole lines: sometimes only one way to finish a line avoids three in a row or copying another line.

Difficulty

• Easy: 6×6 with plenty of clues. Normal: 8×8, solvable with the tips above. Hard: 10×10 with as few clues as possible.
• Every puzzle is new. Your best times are kept for each difficulty.

Keyboard

• Arrow keys to move, 0 or 1 to place, Space to cycle, Backspace to clear, H for a hint, and Ctrl or ⌘+Z to undo.

Questions

Strategy guides