Fungi is a 2-player set collection game. You are collecting mushrooms. You can find these mushrooms in the forest, a row of eight forest cards in the middle of the table. The first two cards in the row are mushrooms that are right in front of your feet, you can collect one of those cards for free in your turn. You can also collect mushrooms deeper into the forest, but you have to walk longer and that's why you have to pay some sticks before you can grab them.
