Astronauts love floating in space, but not all by themselves. Tether them together so they don't drift through the galaxy alone.
Each card in Tether has a two-digit number in the top corner, and when you rotate the card 180 degrees, the number in the opposite corner has the same two digits, but the positions are swapped. For instance the card with a 68 in one corner has 86 in the opposite corner. Opponents sit across the table from each other, which means that when you play a card each player sees a different number.
You can connect astronauts together if they have consecutive numbers. One player (or team) connects astronauts together horizontally on the table and the other connects them vertically. Since each side sees a different number and connects in a different direction, but is playing with the same astronauts, you have an asymmetric puzzle with a lot of interaction between players.
—description from the designer