The joker card, the "Tractor" one, has two possible uses.

During your turn, you may discard it and this allows you to continue the game on your left without playing any other cards.

It’s a very useful defensive action to avoid passing, but it is also an important strategic choice, if we can use it to delay the release of a valuable card for our opponents.

The other use is to replace any card numbered 1 through 16 (therefore excludes all final fruits / vegetables), but in order to play this type of move is also essential to position the immediately following card of the sequence .

If you do not have such card, the joker cannot be played.

It is possible to use more than one joker in the same sequence

In the example on the left you see how the player who needed the black 8 card has played the "Tractor" followed by 12.

The player whose card has been replaced may discard it at any time, but the effects of this move become active only when it’s the players’ effective turn.