- 1Put a 🐱 or a 🐶 in every square.
- 2No more than two of the same animal side by side, across or down.
- 3Every row and every column holds three cats and three dogs.
- 4An = between two squares means the same animal; a × means different ones.
Tap a square once for a cat, twice for a dog, a third time to clear it. The grey squares are given and stay put. Every board has one answer you can reach by logic alone, so you never need to guess.
Grids like this are known as binary puzzles, also called Takuzu or Binairo. Tango and Cats & Dogs add the = and × signs.
Three moves that open every board
Two alike side by side: the squares at both ends must be the other animal. A gap between two alike: the middle square must be the other animal. A full half: once a row has three cats, the rest of it is dogs. Follow the signs as you go, and the board fills itself in.