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How to play Binairo

Three rules, one solution, no guessing. Here's each rule with a board you can tap.

Updated 12 October 2026 · 6 min read

What are the rules of Binairo?

Binairo is a grid puzzle with two symbols — owls and foxes here, 0s and 1s in the classic version. Every row and column must hold the same number of each symbol, and no three identical symbols may sit next to each other in a line. Some puzzles add = and × links between cells. Each puzzle has exactly one solution.

What is a binary puzzle?

"Binary puzzle" is the generic name for this family: any grid you fill with exactly two symbols under balance and no-three rules. Binairo, Takuzu, Tic-Tac-Logic, Simon Tatham's Unruly and LinkedIn's Tango are all versions of it. Learn it once and you can play any of them.

Rule 1 — Balance

Every row and every column contains the same number of owls and foxes. On a 6×6 that's three of each per line; on an 8×8, four of each.

Pip: Count first. This row already has three owls — half of six — so every empty cell must be a fox.

Interactive example · 1 of 3 · tap the empty cells

Rule 2 — No crowds

Never three identical animals in a row, horizontally or vertically. Two together is fine; three is a crowd.

Pip: Two owls together, so the cells either side can't be owls — that would make three. Place both foxes, and you've made a fox pair. Same rule again for the last cell.

Interactive example · 2 of 3 · tap the empty cells

Rule 3 — Links (Plus puzzles)

Some puzzles show a small = or × on the edge between two cells. = means the two cells hold the same animal; × means they differ.

Pip: The = joins an owl to an empty cell, so that cell is an owl too. The × means the cell beside the fox is an owl. Three owls now — the rest are foxes.

Interactive example · 3 of 3 · tap the empty cells

What you're promised

Every Hoot & Fox puzzle has exactly one solution and can be reached by deduction alone. If you feel you have to guess, there's a technique you haven't spotted yet — the techniques guide walks through all seven.

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