Read the rules before trusting a label
We checked the publishers' own instructions for the versions listed below. Puzzle Binairo explicitly calls its game Takuzu and uses black and white circles. Q42 describes 0h h1 as a game whose concept is also known as Takuzu or Binary Sudoku. Conceptis uses the name Tic-Tac-Logic and fills cells with X or O. Each of these sources specifies the same three classic constraints.
For the versions in this table, you can carry familiar deductions from Binairo to Takuzu after translating the symbols. For another app, open its rules or help panel before assuming a match. Each row below names the version we checked, with a source number leading to its original instructions. This also gives you a place to check a name when a puzzle sheet offers little explanation.
| Name and source | Symbols | Rules to expect |
|---|---|---|
| Binairo / Takuzu at Puzzle Binairo [1] | Black and white circles | Equal counts in every line, no triples, unique rows and columns. |
| Classic Binary Puzzle on this site [2] | 0 and 1 | Equal counts in every line, no triples, unique rows and columns. |
| Classic Tic-Tac-Logic by Conceptis [3] | X and O | Equal counts in every line, no triples, unique rows and columns. |
| Binoxxo Unlimited by AculApps [4] | X and O | The developer lists equal counts, no triples and unique rows and columns. |
| 0h h1 by Q42 [5] | Two tile colors | Equal counts in every line, no triples, unique rows and columns. |
Map numbers, colors and X/O consistently
Choose one translation and keep it for the whole board. You might write black as 0 and white as 1, or X as 0 and O as 1. Those assignments are conventions for your notes. Swapping both symbols everywhere preserves equal counts, identical-line comparisons and runs of matching cells. Swapping them halfway through your notes can change the puzzle you are trying to solve.
For a small translation exercise, map X to 0 and O to 1. The six-cell row X O X O O X becomes 0 1 0 1 1 0. Both descriptions contain three of each symbol and no triple. This checks one row only. Its crossing columns and any duplicate rows still need checking on a complete board.
The same translation turns X _ X into 0 _ 0, where the underscore marks an empty cell. Under the no-triples rule, the middle cell must be O, or 1 in your notes. A pair of colored tiles carries the same information when the instructions prohibit three matching tiles consecutively.
When comparing Binoxxo vs Takuzu, pay attention to where each symbol appears. An X inside a Binoxxo cell is one of its two values. A small x between cells in a relationship-clue puzzle specifies how those cells relate. Check where the mark sits before copying it into your notes.
X O X O O X0 1 0 1 1 0Here X means 0 and O means 1. Both rows have three of each symbol and no triple; this is a notation example, not a complete puzzle.
Use one rule checklist across publishers
First, check the counts. Classic rules require half of each symbol in every row and every column. A six-cell line needs three of each; an eight-cell line needs four. Read the dimensions too. On an even rectangular board, a row's quota comes from its width and a column's quota from its height.
Next, find the adjacency rule. It should forbid three consecutive matching cells horizontally or vertically. Diagonals do not enter the classic check. X and O can suggest ordinary tic-tac-toe, where making a line of three wins, so read the stated objective before importing habits from that game.
Then check line uniqueness explicitly. In the classic versions above, two completed rows cannot match cell for cell, and two completed columns cannot match either. A row can have the same sequence as a column. This condition concerns entire lines, so repeated pairs such as 00 are still permitted.
Keep that rule separate from a publisher's promise of one solution. Unique lines restrict the completed grid. A unique solution means only one completed grid fits the starting clues and all applicable rules. Knowing that a puzzle has one answer does not tell you which line constraints it uses.
Where the names stop being interchangeable
For 0h h1 and Takuzu, Q42's listed rules confirm the classic match, including line uniqueness. You can translate its two colors into digits without adding Sudoku's nine-digit or box requirements. The phrase Binary Sudoku on its About panel refers to this two-symbol game.
Several related versions need a separate check. Puzzle Binairo's Binairo+ uses relationship marks and permits repeated lines; our Binairo Plus guide explains that version. Simon Tatham's Unruly makes unique rows and columns an optional setting, so check whether it is enabled. PeterFrank's Odd Binairo requires one more 1 than 0 in each line, which changes the counting quota.
Our game uses classic Binary Puzzle rules with 0 and 1. Open the 6x6 board and choose Easy to try a move in the new notation. Keep your symbol mapping beside your notes and translate a deduction before entering its digit. For example, if your paper notes say the missing cell must be O and you chose O as 1, enter 1.