Binary Puzzle
Fill every square with a sun or a moon. No more than two alike may sit side by side, every row and column holds as many suns as moons, and no two rows or columns are the same.
How to play Binary Puzzle
The rules
Fill the grid so that no more than two suns or two moons sit next to each other in a row or column, each row and each column has as many suns as moons, and no two rows (or two columns) are exactly the same. Squares with a small brass pin are given and stay as they are. Breaking a rule draws a dashed outline around the problem and says what is wrong.
How to play
Tap a square once for a sun, twice for a moon and a third time to clear it. Press and hold (or right-click) to put a moon in straight away. On a keyboard, use the arrow keys, then 1 for a sun, 2 for a moon, 0 to clear, or Space to cycle. Undo takes back one move.
Techniques
Two alike side by side need the other symbol on both ends, and a gap between two alike takes the other symbol. A row or column that has all its suns gets moons in the rest, and the other way round. When that runs out, count: if a row still needs one sun, try each spot and see which ones would leave three moons together. Last, a row that is nearly done must not end up as a copy of a finished row.
Levels and daily
The 6×6 puzzles need only pairs, gaps and full lines, sometimes a little counting. Every 8×8 needs counting. Every 10×10 also needs the rule that no two rows or columns are the same. The daily puzzle is an 8×8, the same for everyone, and changes at midnight UTC.
Questions
What are the rules of a binary puzzle?
Fill a square grid with two symbols, here suns and moons. No more than two of the same may be next to each other in a row or column, every row and column has the same number of each, and no two rows or two columns may be identical.
Is this the same as Takuzu or Binairo?
Yes. Binary Puzzle follows the same rules as the puzzle also known as Takuzu or Binairo, which is usually played with 0s and 1s. Here you place suns and moons, and the puzzles are our own.
Does every puzzle have exactly one solution?
Yes. Every puzzle was checked by a search that found exactly one solution, and solved by a step-by-step solver that uses only logical deductions, so you never need to guess.
Any tips for solving it?
Look for pairs and gaps first, then fill rows and columns that already have all their suns or all their moons. When you get stuck, count what a row still needs. Hint finds the next step from your position, fills it in and explains why; if one of your squares is wrong, it clears that first.
Is there a daily binary puzzle?
Yes. The daily puzzle is an 8×8 that is the same for everyone and changes at midnight UTC. Earlier dailies are under Past dailies.