The rules of this version (other versions may have slight differences) are as follows:
The deck is shuffled, and four cards are given into your hand. These cards are the contents of a dungeon room.

The spades and clubs are monsters. Flipping a monster card will start a battle, in which the monster will deal you its value worth of damage before being defeated. Number cards are worth 2 to 10, jacks, queens, kings and aces are 11,13,15 and 17.

The diamonds are shields. Flipping a shield card will equip the shield, and reduce the damage dealt by monsters by its value. However, a shield can only be used against monsters in descending order of value, otherwise it breaks and you receive full damage. Number cards are worth 2 to 10 and face cards are worth 11.

The hearts are health potions. Flipping one will consume the potion and recover health points according to its value, up to a maximum of 21. However, if you try drinking two or more potions in a row, the later potions will not have any effect. Number cards are worth 2 to 10 and face cards are worth 11.

The jokers are Donsols, the two extra-powerful monsters with a value of 21. This means that even at full health, you need a brand-new shield to defeat them.