Cards represent D&D chromatic and metallic dragons (red, white, gold, bronze, etc.), which all have a strength and a power.
At the start of a game, every player has 50 Gold Pieces, and the game ends when one player has 0 or fewer at the end of a round. The one with the most GP wins.
A game is made of a series of rounds in which each player will play 4 cards : one for determining first player and ante, and three others to determine who will win the Ante.
Metallic dragons draw cards, while chromatic ones steal cards or money from the ante (gold dragons let you draw 1 card per other metallic ones you've played, for instance, and black dragons steal 2 GP from the ante).
You need to play a card whose strength is inferior or equal to previous player's card to activate its power. Otherwise, it will only contribute to your total strength.
There are also mortals card (the druidess is the most famous, as she reverses the winning condition), a Dracolich and, of course, one Bahamut and a Tiamat.