Each player in Blanco starts with a face-down 3×3 grid of cards, with each card showing a number (1-12) and a colored vertical stripe. To complete set up, turn one card face up, look at another card, then draw a hand of two cards.

On a turn, draw a card from the deck or discard pile, then either (1) discard a card and reveal a face-down card in your grid or (2) discard a grid card and replace it with a face-up card from your hand. Alternatively, instead of drawing a card, you can swap two orthogonally adjacent cards, turning one of them face up, if possible.

If all cards in a vertical column now have the same color, clear that column; if all cards in a horizontal row now have the same number, clear that row. Whenever you clear a row, you may look at one of your face-down cards. If you manage to have a chain reaction clearing two lines on the same turn you may turn over one of your face-down cards.

As soon as you have cleared your 3×3 grid, deal yourself a new face-down 4×3 grid, then turn one card face up and look at another. Whoever first clears their 4×3 grid wins.