Binary Grid is a deduction puzzle built from only two values, but every entry affects two complete lines. A placement can settle the balance in its row, prevent a triple in its column and distinguish one line from another at the same time.
How Binary Grid works
Each square contains either a zero or a one. On an even-sized board, every row and column must contain exactly half of each value. Three identical values may never touch horizontally or vertically, and no two completed rows or columns may be identical.
The fixed dark squares are clues and cannot be changed. Select any empty square to cycle through 0, 1 and blank, or type 0 and 1 directly. The game marks a conflict as soon as the current entries break a published rule.
If two adjacent cells are both 1, the next cell on either side must be 0. The same rule works vertically and with zeros.
A dependable solving order
- Find pairs and sandwiches. Complete patterns such as 11_ with 0, or 1_1 with 0. These are the clearest forced moves.
- Count each nearly full line. Once a row has all of its zeros, every remaining square in that row must be 1, and vice versa.
- Compare almost-matching lines. If a nearly complete row would duplicate another, its last undecided cells must make it different.
- Recheck both directions. Every horizontal deduction changes a column. Scan that column before moving elsewhere.
A good Binary Grid rarely requires blind guessing. When progress stops, one of the three rules usually creates a forced entry in a different part of the board. The Check Grid button reports rule conflicts but never supplies a hidden value.
What changes between difficulty levels?
| Level | Grid | Fixed clues | Cells to fill | Time limit |
|---|---|---|---|---|
| Easy | 4 × 4 | 8 | 8 | 2:30 |
| Standard | 6 × 6 | 18 | 18 | 6:00 |
| Hard | 8 × 8 | 28 | 36 | 10:00 |
Larger boards create more interactions between distant lines and give the uniqueness rule more work to do. Results stay separate by difficulty so a quick 4 × 4 solve is not compared directly with an 8 × 8 puzzle.
How Binary Grid scoring works
Completing the unique grid contributes 75% of the score. Control contributes 20% and is reduced by failed checks and resets. Pace contributes only 5%, so careful deduction matters much more than hurried entry.
An unfinished attempt receives limited credit for correct editable cells but cannot receive completion or pace credit. Undo is free because it simply restores the previous cell state; Reset is recorded because it clears the complete working grid.
The score is a recreational result for comparing your own attempts at the same level. It is not an intelligence, educational, medical or neurological assessment.
How puzzles are generated and verified
The generator first builds a complete valid board from legal row patterns. It then removes clues one at a time. After every removal, an independent exact solver searches for solutions and the removal is retained only when exactly one solution remains.
The published clue counts are exact, not estimates. Validation checks the board dimensions, clue count, every given value, all three rules and the uniqueness proof before a puzzle reaches the player. Identical seeds reproduce identical puzzles.
Keyboard and touch controls
Every square is a native button with its row, column, clue state, value and conflict state in its accessible name. Arrow keys move through the grid. Press 0 or 1 to enter a value, Delete or Backspace to clear it, or use Enter and Space to cycle the selected square.
The 8 × 8 grid remains touch-operable at the supported mobile width, though larger boards are naturally more comfortable on a wider display. Live text reports progress, checks, conflicts, pauses and completion without relying on colour alone.
Binary Grid questions
Is Binary Grid the same kind of puzzle as Takuzu or Binairo?
Yes. Those names commonly describe the same core family of balanced zero-and-one puzzles with no triples and unique rows and columns.
Does every puzzle have one solution?
Yes. The generator removes each clue conditionally and the exact solver must find one solution—not zero and not two—before the puzzle is accepted.
Does Check Grid reveal an answer?
No. It identifies rule conflicts or confirms that the current partial grid has no visible conflict. It does not place a value or reveal the solution.
Are puzzles repeated?
A finite board size has a finite set of states, so no claim of literal infinity is made. Fresh standalone seeds provide a large renewable supply, and identical seeds remain reproducible for testing.
Can Binary Grid appear in the Daily Brain Workout?
Not yet. Binary Grid launches as a standalone Logic game while its Standard duration and scoring are evaluated separately. Pattern Sequence remains the current Daily Logic exercise.