The 16 Quarto pieces explained

About us: we make Quads, an independent game built on the same hand-your-opponent-the-piece mechanic as Quarto. It isn't affiliated with Gigamic or the makers of Quarto.

The four traits

Each piece answers four yes-or-no questions. Quads uses the same set as classic Quarto, drawn from above, so a tall piece is shown as a bigger one.

Every trait splits the set exactly in half. That is why no trait is easier to win with than another at the start of a game.

All 16 pieces

The binary column writes each piece as four digits, one per trait. Reading from the right, the digits stand for height, colour, shape and top, and a 1 means tall, dark, square or solid. Counting from 0000 to 1111 lists every piece once. This is also how the Quads app stores a piece, as a number from 0 to 15. Teachers use it to introduce 4-bit numbers, and the classroom guide has an activity built on it.

How much any two pieces have in common

Pick any piece. The other 15 are related to it in a fixed pattern:

So every piece has exactly one opposite. The tall dark square hollow piece and the short light round solid piece share nothing, and a line that contains both can never be won. For every other pair there is at least one trait in common.

Why the counts matter when you play

You win by placing the fourth piece in a row, column or diagonal where all four share at least one trait. Quads, like the advanced Quarto variant, also counts a 2×2 square. Since your opponent chooses the piece you place, the question on every turn is which of the remaining pieces are safe to hand over.

• Each trait value starts with 8 pieces. If three dark pieces sit in a line, any dark piece still in the tray wins it. Count how many are left before you hand one over.
• A line can be open on more than one trait. Three pieces that are all dark and all round can be finished by any dark piece or any round one. That is far more pieces than a single shared trait.
• Opposites close a line. Once a line holds two pieces with nothing in common, nobody can win it.
• The tray runs out. With one piece per combination, the safe pieces get used up. Late in the game a player can be left with only losing pieces to hand over.

The strategy guide works through these ideas with example positions.

Physical Quarto pieces and the Quads app

Classic Quarto, designed by Blaise Müller and published by Gigamic, uses wooden pieces that stand on the board: tall or short, light or dark wood, round or square, with a flat top or a hollowed one. Quads shows the board from above, so height becomes size and the hollow becomes a visible centre. The 16 combinations are the same, and so is the logic of the game.

Frequently asked questions