Rule changes when playing at yucata.de
If you can't move and need to exchange cards you need to show your hand cards to your opponent. This is intended to prevent that a player overlooks a legal move or even tries cheating. On yucata.de the system checks for legal moves, thus it is not necessary to show your hand cards to your opponent when exchanging cards.
According to the original rules, cubes are taken blindly from the bag and distributed on the mats. This leads regularly to a lock-up of the game. E.g. there are five gray cubes and five gray cards in the game. If the grey cubes are all at the same time on the mats and the cards are distributed to all mats, it is not possible to finish the mats any more: the game is blocked. The implemented algorithm ensures that there are always less cubes of a colour in the game than which are needed to claim a cup. I.e. never more than two gray, three blue and so on.
The original rules do not list the cards contained in the game. The following cards exist:
The rules regarding 3:1 exchange are not very clear in the original rules. In fact, there is nothing like a 3:1 exchange. But, when claiming a cup, you may substitute a missing cube by three other cubes with the same colour, given that their cup has already been claimed. E.g. you may "pay" for the green cup four green and three yellow cubes, given that the yellow cup has already been awarded. You may also substitute more than one cube. Thus, you may "pay" six red cups and three green ones for the gray cup, given that the red and green cup had been awarded earlier.
Cubes used for payment are not put back into the bag: they are taken out of the game.