Unruly vs Takuzu and the Unique Rows Setting

Read the setting before comparing boards

We checked the full Unruly manual, including its parameters section. It places the options under Custom in the Type menu. Find the checkbox labelled Unique rows and columns. The manual says that, when enabled, “no two rows are permitted to have exactly the same pattern”, with the corresponding restriction for columns.

Turning that option off removes the ban on repeated completed lines. Equal counts and the prohibition on three consecutive matching cells still apply. Use the setting shown for your game rather than assuming that every Unruly app or preset has the same configuration. This comparison concerns Simon Tatham’s documented version.

Width and height are separate parameters, and both must be even. Difficulty controls the generated challenge. Changing difficulty does not by itself explain whether a duplicate line is legal; the uniqueness option answers that question.

• Read the official Unruly parameters

Test one completed grid under both settings

The original six-by-six grid below uses 0 and 1 as a paper transcription of two colors. Keep one mapping throughout. Rows 1 and 4 both read 010101. The matching rows are separated. We still need to check the columns, because legal individual rows can form an illegal vertical run.

Every row contains three zeros and three ones, with no horizontal triple. Read the columns downward and you get 001011, 100101, 011010, 100110, 011001 and 110100. Those six columns are balanced, contain no triple, and are all different. Only the repeated row breaks the classic rules.

With uniqueness disabled, this is a legal completed arrangement. Enable uniqueness and it fails because rows 1 and 4 match. Classic Takuzu rejects it for the same reason. No symbol changed during that comparison; the extra requirement changed which completed boards are permitted.

Check columns independently of rows

Transpose the first example by turning each of its columns into a row. The resulting grid appears below. Its six rows are now distinct, while columns 1 and 4 both read 010101. Balance and the absence of triples survive the transpose because rows and columns exchange roles.

This second example passes with uniqueness off and fails with it on. It shows why checking only for repeated rows is insufficient. To verify a completed classic board, compare every column with the other columns as well.

Rows and columns belong to separate comparison groups. A row is allowed to match a column, even with uniqueness enabled. Rejecting such a cross-direction match would add a restriction that neither the classic rules nor the documented Unruly option requires.

Keep deductions based on counts and triples

The familiar pair and sandwich deductions work in both configurations. In 0 0 _ 1 _ 1, the opening pair forces the third cell to 1. The row then contains three ones, so its fifth cell must be 0, producing 0 0 1 1 0 1. Both steps use rules that remain active.

The same reasoning applies to colors once you translate them consistently. Two black cells followed by a blank force a white cell if another black would make three. A line that has already reached its quota forces the opposite color into every remaining blank.

These are line deductions. A proposed completion still has to fit crossing lines. Passing a row’s local tests gives you useful information without certifying an entire finished board.

Use duplicate-line elimination only when supported

Now suppose one completed row is 010101 and another row reads 01__01. The unfinished row needs one more zero and one more one. Exactly two patterns satisfy its local balance and adjacency requirements, 010101 and 011001.

With line uniqueness enabled, the already completed row excludes 010101. The other row must become 011001, putting 1 then 0 into the two blanks. With uniqueness disabled, both row candidates survive that comparison. Crossing columns may still decide between them, but the completed row alone cannot.

If you have used this deduction in an Unruly game whose option is off, revisit the first affected entry. Keep placements justified independently by counts or triples. Undo a value whose only support was avoiding a repeated line, then inspect its crossing column again.

Separate line uniqueness from a unique solution

A publisher’s promise that a puzzle has one solution concerns the whole starting position. Line uniqueness specifies which completed boards count as answers. A uniquely solvable puzzle can use rules that permit repeated lines; the promise alone cannot justify eliminating a repeated row.

The two full grids here demonstrate legality under specified constraints. They are original checked examples, without starting-clue sets or difficulty ratings. They do not claim to reproduce a puzzle generated by Unruly.

For classic practice on this site, line uniqueness is always active. Read the worked uniqueness guide before trying an 8x8 puzzle, where each row and column needs four zeros and four ones. If you are comparing names across other apps, use the Binairo and Takuzu guide to check their stated rules.

• Work through classic row and column uniqueness
• Compare Binairo and Takuzu names and rules
• Practice on a classic 8x8 board

Rules and example verification

The official manual establishes the optional rule. BinaryPuzzle.com supplies the classic rule comparison. Both completed grids and the candidate lists were independently checked for this article, then cross-checked against our classic validator.

• Simon Tatham’s Unruly manual
• BinaryPuzzle.com classic rules