Build a House of Cards. Stack your cards carefully. For the construction of the walls you have to click on two cards of the same suit or the same value. For the roofs you can click on any card. The walls need to be supported by pairs with equal or higher value or the walls below will collapse. There are two special pairs: 20 and 21. A pair with a value of 20 can be placed on top of any other pair (even lower values). A pair with a value 21 can be placed on top of any pair and will also strenghen the walls directly below. Complete the house and you will advance to the next level.